Forest Pest Insects

in North America:

A Photographic

Guide

Roy G. Van Driesche

Joseph H. LaForest

Charles T. Bargeron

Richard C. Reardon

Megan Herlihy

FHTET-2012-02

September 2013

Center for Invasive Species and

Ecosystem Health Warnell School of 

Forestry and Natural Resources

College of Agricultural 

and Environmental Sciences
Forest Pest Insects in North America:

A Photographic Guide
Forest Pest Insects

in North America:

A Photographic

Guide



Forest Pest Insects

in North America:

A Photographic

Guide

Roy G. Van Driesche1

Joseph H. LaForest2

Charles T. Bargeron2

Richard C. Reardon3

Megan Herlihy1

1University of Massachusetts, Environmental Conservation/Entomology

2University of Georgia

3USDA Forest Service, Forest Health Technology Enterprise Team

FHTET-2012-02

September 2013

Center for Invasive Species and

Ecosystem Health Warnell School of 

Forestry and Natural Resources

College of Agricultural 

and Environmental Sciences
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs 

and activities on the basis of race, color, national origin, sex, religion, age, disability, 

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bases apply to all programs.) Persons with disabilities who require alternative means 

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contact USDA’s TARGET Center at 202-720-2600 (voice and TDD). 

To file a complaint of discrimination, write USDA, Director, Office of Civil Rights, 

Room 326-W, Whitten Building, 1400 Independence Avenue SW, Washington, DC 

20250-9410 or call 202-720-5964 (voice and TDD). USDA is an equal opportunity 

provider and employer.

Federal Recycling Program

Printed on recycled paper

Cover Image Credits

Ponderosa pine stand; Chris Schnepf, University of Idaho, Bugwood.org

Male pine butterfly, Neophasia menapia; Terry Spivey, USDA Forest Service, 

Bugwood.org

For additional copies of this publication, contact:

Richard C. Reardon

USDA Forest Service

180 Canfield Avenue

Morgantown, WV 26505

304-285-1566

rreardon@fs.fed.us

An electronic version of this publication is available online at: 

http://www.forestpests.org/book/
The information in this publication is intended to help foresters, urban 

landscaping employees, or others working with trees recognize some of 

the common native and nonnative pest insects affecting trees in North 

America, and understand their life cycles and how they damage trees. 

Recognition is based on photographs of the pest in various lifestages 

rather than on technical keys, and the user’s identification of a pest 

may not be accurate if there are many similar species in a group. The 

information was drawn from books, websites, factsheets, and some 

original literature. This publication is not a guide for specialists. In 

many groups, such as the bark beetles and aphids, confirmation of 

species identity requires attention to details not visible in photos with 

comparisons to other similar species and use of keys. Information on 

important biological control agents of each species is provided when 

available. Sources for further information (websites and articles) are 

given at the bottom of each species’ page; however, an exhaustive 

review of the literature was beyond the scope of this project. In most 

cases, pages on individual species were reviewed by experts with direct 

knowledge of the species. While any residual mistakes remain mine 

(Roy Van Driesche), I am deeply indebted to the many people who 

greatly improved pages on particular insects with their comments, 

photos, and edits. I would also like to thank Wendy Harding for 

design and layout of this printed version.

Preface

1. Pear Thrips, Taeniothrips inconsequens (Uzel) (Thysanoptera: Thripidae) . . . . . . . . . . . . . . . . . . . 1

2. Introduced Basswood Thrips, Thrips calcaratus Uzel (Thysanoptera: Thripidae) . . . . . . . . . . . . . . . 3

3. Redbanded Thrips, Selenothrips rubrocinctus (Giard) (Thysanoptera: Thripidae) . . . . . . . . . . . . . . 6

4. Slash Pine Flower Thrips, Gnophothrips fuscus (Morgan) (Thysanoptera: Phlaeothripidae) . . . . . . 9

5. Northern Walkingstick, Diapheromera femorata (Say) (Phasmatodea: Heteronemiidae) . . . . . . . . 11

6. Oak Lace Bug, Corythucha arcuata (Say) (Hemiptera: Tingidae) . . . . . . . . . . . . . . . . . . . . . . . . . . 15

7. Sycamore Lace Bug, Corythucha ciliata (Say) (Hemiptera: Tingidae) . . . . . . . . . . . . . . . . . . . . . . 18

8. Shield-backed Pine Seed Bug, Tetyra bipunctata (Herrich-Schäffer) 

 (Hemiptera: Scutellaridae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

9. Leaffooted Pine Seed Bug, Leptoglossus corculus (Say) (Hemiptera: Coreidae) . . . . . . . . . . . . . . 25

10. Royal Palm Bug, Xylastodoris luteolus Barber (Hemiptera: Thaumastocoridae) . . . . . . . . . . . . . 27

11. Saratoga Spittlebug, Aphrophora saratogensis (Fitch) (Hemiptera: Cercopidae) . . . . . . . . . . . . . 29

12. Pine Spittlebug, Aphrophora parallela (Say) (Hemiptera: Cercopidae) . . . . . . . . . . . . . . . . . . . . . 32

13. Thorn Bug, Umbonia crassicornis (Amyot and Serville) (Hemiptera: Membracidae) . . . . . . . . . . 34

14. Periodical Cicada, Magicicada septendecim L. (Hemiptera: Cicadidae) . . . . . . . . . . . . . . . . . . . . 36

15. Eastern Spruce Gall Adelgid, Adelges abietis (L.) (Hemiptera: Adelgidae) . . . . . . . . . . . . . . . . . . 41

16. Balsam Woolly Adelgid, Adelges piceae (Ratzeburg) (Hemiptera: Adelgidae) . . . . . . . . . . . . . . . 44

17. Hemlock Woolly Adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae) . . . . . . . . . . . . . . . . . 48

18. Cooley Spruce Gall Adelgid, Adelges cooleyi (Gillette) (Hemiptera: Adelgidae) . . . . . . . . . . . . . . 53

19. Pine Bark Adelgid, Pineus strobi (Hartig) (Hemiptera: Adelgidae) . . . . . . . . . . . . . . . . . . . . . . . . 56

20. Pine Leaf Adelgid, Pineus pinifoliae (Fitch) (Hemiptera Adelgidae) . . . . . . . . . . . . . . . . . . . . . . . 59

21. White Pine Aphid, Cinara strobi (Fitch) (Hemiptera: Aphidae) . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

22. Woolly Elm Aphid, Eriosoma americanum (Riley) (Hemiptera: Aphididae; Eriosomatinae) . . . . . 64

23. Woolly Beech Aphid, Phyllaphis fagi (L.) (Hemiptera: Aphidae) . . . . . . . . . . . . . . . . . . . . . . . . . . 66

24. Tuliptree Aphid, Illinoia liriodendri (Monell) (Hemiptera: Aphididae) . . . . . . . . . . . . . . . . . . . . . . . 68

25. Norway Maple Aphid, Periphyllus lyropictus (Kessler) (Hemiptera: Aphidae) . . . . . . . . . . . . . . . . 70

26. Linden Aphid, Eucallipterus tiliae (L.) (Hemiptera: Aphididae) . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

27. Spruce Aphid, Elatobium abietinum (Walker) (Hemiptera: Aphidae) . . . . . . . . . . . . . . . . . . . . . . . 76

28. Beech Scale, Cryptococcus fagisuga Lindinger (Hemiptera: Eriococcidae) . . . . . . . . . . . . . . . . . 79

29. Gillette’s Eriococcin, Eriokermes gillettei (Tinseley) 

 (Hemiptera: Kermesidae, formerly Eriococcidae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

30. Pine Bast Scale, Matsucoccus matsumurae (Kuwana) (Hemiptera: Matsucoccidae) . . . . . . . . . . 86

31. Tuliptree Scale, Toumeyella liriodendri (Gmelin) (Hemiptera: Coccidae) . . . . . . . . . . . . . . . . . . . 88

32. Pine Tortoise Scale, Toumeyella parvicornis (Cockerell) (Hemiptera: Coccidae) . . . . . . . . . . . . . 91

33. Tessellated Scale, Eucalymnatus tessellatus (Signoret) (Hemiptera: Coccidae) . . . . . . . . . . . . . 95

Contents
34. Elongate Hemlock Scale, Fiorinia externa Ferris (Hemiptera: Diaspididae) . . . . . . . . . . . . . . . . . 97

35. Oystershell Scale, Lepidosaphes ulmi (L.) (Hemiptera: Diaspididae) . . . . . . . . . . . . . . . . . . . . . 101

36. San José Scale, Diaspidiotus perniciosus (Comstock) (Hemiptera: Diaspididae) . . . . . . . . . . . 105

37. Willow Scale, Diaspidiotus gigas (Thiem and Gerneck) (Hemiptera: Diaspididae) . . . . . . . . . . . 110

38. Camphor Scale, Pseudaonidia duplex (Cockerell) (Hemiptera: Diaspididae) . . . . . . . . . . . . . . . 114

39. Coconut Scale, Aspidiotus destructor Signoret (Hemiptera: Diaspididae) . . . . . . . . . . . . . . . . . 117

40. Florida Red Scale, Chrysomphalus aonidum (L.) (Hemiptera: Diaspididae) . . . . . . . . . . . . . . . . 120

41. Magnolia White Scale, Pseudaulacaspis cockerelli (Cooley) (Hemiptera: Diaspididae) . . . . . . . 122

42. White Peach Scale, Pseudaulacaspis pentagona (Targioni-Tozzetti) 

 (Hemiptera: Diaspididae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124

43. Citrus Whitefly, Dialeurodes citri (Ashmead) (Hemiptera: Aleyrodidae) . . . . . . . . . . . . . . . . . . . 126

44. The Mealybug Oracella acuta (Lobdell) (Hemiptera: Pseudococcidae) . . . . . . . . . . . . . . . . . . . 130

45. Cottonwood Leaf Beetle, Chrysomela scripta Fabricius (Coleoptera: Chrysomelidae) . . . . . . . . 133

46. Imported Willow Leaf Beetle, Plagiodera versicolora (Laicharting) 

 (Coleoptera: Chrysomelidae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

47. Elm Leaf Beetle, Xanthogaleruca luteola (Müller) (Coleoptera: Chrysomelidae) . . . . . . . . . . . . 139

48. Larger Elm Leaf Beetle, Monocesta coryli (Say) (Coleoptera: Chrysomelidae) . . . . . . . . . . . . . 144

49. Giant Palm Weevil, Rhynchophorus cruentatus (F.) (Coleoptera: Curculionidae) . . . . . . . . . . . . 147

50. Red Palm Weevil, Rhynchophorus ferrugineus (Olivier) (Coleoptera: Dryophthoridae) . . . . . . . 150

51. Pales Weevil, Hylobius pales (Herbst) (Coleoptera: Curculionidae) . . . . . . . . . . . . . . . . . . . . . . 154

52. Pine Root Collar Weevil, Hylobius radicis (Buchanan) (Coleoptera: Curculionidae) . . . . . . . . . . 157

53. Pitch-eating Weevil, Pachylobius picivorus (Germar) (Coleoptera: Curculionidae) . . . . . . . . . . . 160

54. White Pine Weevil, Pissodes strobi (Peck) (Coleoptera: Curculionidae) . . . . . . . . . . . . . . . . . . . 163

55. Eastern Pine Weevil, Pissodes nemorensis Germar (Coleoptera: Curculionidae) . . . . . . . . . . . 167

56. Whitefringed Beetles (Naupactus spp.) (Coleoptera: Curculionidae) . . . . . . . . . . . . . . . . . . . . . 170

57. Yellow-poplar Weevil, Odontopus calceatus (Say) (Coleoptera: Curculionidae) . . . . . . . . . . . . . 174

58. Native Elm Bark Beetle, Hylurgopinus rufipes (Eichhoff) 

 (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

59. Smaller European Elm Bark Beetle, Scolytus multistriatus (Marsham) 

 (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182

60. Spruce Beetle, Dendroctonus rufipennis (Kirby) (Coleoptera: Curculionidae, Scolytinae) . . . . . 186

61. Black Turpentine Beetle, Dendroctonus terebrans (Olivier) 

 (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191

62. Eastern Larch Beetle, Dendroctonus simplex (LeConte) 

 (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196

Contents (continued)
63. Southern Pine Beetle, Dendroctonus frontalis (Zimmermann) 

 (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200

64. Western Pine Beetle, Dendroctonus brevicomis LeConte 

 (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207

65. Jeffrey Pine Beetle, Dendroctonus jeffreyi Hopkins 

 (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212

66. Mountain Pine Beetle, Dendroctonus ponderosae Hopkins 

 (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216

67. Douglas-fir Beetle, Dendroctonus pseudotsugae Hopkins 

 (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220

68. Engraver Beetle, Ips typographus (L.) (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . . . 224

69. Pine Engraver Beetle, Ips pini (Say) (Coleoptera: Curculionidae [formerly Scolytidae]) . . . . . . . 229

70. Southern Pine Engraver, Ips grandicollis (Eichhoff) 

 (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234

71. Six-spined Ips, Ips calligraphus (Germar) (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . 238

72. Small Southern Pine Engraver, Ips avulsus Eichhoff 

 (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243

73. Silver Fir Beetle, Pseudohylesinus sericeus (Mannerheim) 

 (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248

74. Fir Engraver, Scolytus ventralis LeConte (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . 250

75. Columbian Timber Beetle, Corthylus columbianus Hopkins 

 (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254

76. Ambrosia Beetles, Xyleborus spp. (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . . . . . . 257

77. Redbay Ambrosia Beetle, Xyleborus glabratus Eichhoff 

 (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261

78. Walnut Twig Beetle, Pityophthorus juglandis Blackman 

 (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267

79. Striped Ambrosia Beetle, Trypodendron lineatum (Olivier) 

 (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274

80. Black Twig Borer, Xylosandrus compactus (Eichhoff) 

 (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278

81. Larger Pine Shoot Beetle, Tomicus piniperda (L.) 

 (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283

82. White Pine Cone Beetle, Conophthorus coniperda (Schwarz) 

 (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290

83. Lodgepole Cone Beetle, Conophthorus ponderosae Hopkins 

 (Coleoptera: Curculionidae, Scolytinae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295

85. May and June Beetles, Phyllophaga spp. (Coleoptera: Scarabaeidae) . . . . . . . . . . . . . . . . . . . 300

Contents (continued)
86. Black Vine Weevil, Otiorhynchus sulcatus (Fabricius) (Coleoptera: Curculionidae) . . . . . . . . . . 306

87. Strawberry Root Weevil, Otiorhynchus ovatus (L.) (Coleoptera: Curculionidae) . . . . . . . . . . . . . 310

88. Japanese Beetle, Popillia japonica Newman (Coleoptera: Scarabaeidae) . . . . . . . . . . . . . . . . . 313

89. Twolined Chestnut Borer, Agrilus bilineatus (Weber) (Coleoptera: Buprestidae) . . . . . . . . . . . . 317

90. Bronze Birch Borer, Agrilus anxius Gory (Coleoptera: Buprestidae) . . . . . . . . . . . . . . . . . . . . . . 321

91. Emerald Ash Borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) . . . . . . . . . . . . . . 326

92. Goldspotted Oak Borer, Agrilus auroguttatus Schaeffer (Coleoptera: Buprestidae) . . . . . . . . . . 335

93. Soapberry Borer, Agrilus prionurus Chevrolat (Coleoptera: Buprestidae) . . . . . . . . . . . . . . . . . . 340

94. Hickory Spiral Borer, Agrilus torquatus LeConte (Coleoptera: Buprestidae) . . . . . . . . . . . . . . . . 344

95. Flatheaded Appletree Borer, Chrysobothris femorata (Olivier) (Coleoptera: Buprestidae) . . . . . 347

96. Red Oak Borer, Enaphalodes rufulus (Haldeman) (Coleoptera: Cerambycidae) . . . . . . . . . . . . 350

97. Black Fir Sawyer Beetle, Monochamus urussovii (Fischer von Waldheim) 

 (Coleoptera: Cerambycidae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355

98. Japanese Pine Sawyer, Monochamus alternatus Hope (Coleoptera: Cerambycidae) . . . . . . . . 358

99. Asian Longhorned Beetle, Anoplophora glabripennis Motschulsky 

 (Coleoptera: Cerambycidae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365

100. Poplar Borer, Saperda calcarata Say (Coleoptera: Cerambycidae) . . . . . . . . . . . . . . . . . . . . . 373

102. Cottonwood Borer, Plectrodera scalator (Fabricius) (Coleoptera: Cerambycidae) . . . . . . . . . . 377

103. Banded Hickory Borer, Knulliana cincta (Drury) (Coleoptera: Cerambycidae) . . . . . . . . . . . . . 381

104. Locust Borer, Megacyllene robiniae (Forster) (Coleoptera: Cerambycidae) . . . . . . . . . . . . . . . 383

105. White Oak Borer, Goes tigrinus (De Geer) (Coleoptera: Cerambycidae) . . . . . . . . . . . . . . . . . 387

106. Whitespotted Sawyer, Monochamus scutellatus (Say) (Coleoptera: Cerambycidae) . . . . . . . . 390

107. Bagworm, Thyridopteryx ephemeraeformis (Haworth) (Lepidoptera: Psychidae) . . . . . . . . . . . 393

108. Birch Casebearer, Coleophora serratella (L.) (Lepidoptera: Coleophoridae) . . . . . . . . . . . . . . 398

109. Larch Casebearer, Coleophora laricella (Hübner) (Lepidoptera: Coleophoridae) . . . . . . . . . . . 400

110. Pecan Cigar Casebearer, Coleophora laticornella (Clemens) 

 (Lepidoptera: Coleophoridae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405

111. Oak Skeletonizer, Bucculatrix ainsliella Murtfeldt (Lepidoptera: Bucculatricidae) . . . . . . . . . . . 407

112. Palm Leaf Skeletonizer, Homaledra sabalella (Chambers) (Lepidoptera: Coleophoridae) . . . . 411

113. Mimosa Webworm, Homadaula anisocentra Meyrick (Lepidoptera: Galacticidae) . . . . . . . . . . 413

114. Lodgepole Needleminer, Coleotechnites milleri (Busck) (Lepidoptera: Gelechiidae) . . . . . . . . 416

115. Banded Ash Clearwing, Podosesia aureocincta Purrington and Nielson, 

 and Ash/Lilac Clearwing, Podosesia syringae (Harris) (Lepidoptera: Sesiidae) . . . . . . . . . . . . 419

116. Red Oak Clearwing Borer, Paranthrene simulans (Grote) (Lepidoptera: Sesiidae) . . . . . . . . . 423

117. Persimmon Borer, Sannina uroceriformis Walker (Lepidoptera: Sesiidae) . . . . . . . . . . . . . . . . 425

Contents (continued)
118. Poplar Clearwing Borer, Paranthrene dollii (Neumoegen) (Lepidoptera: Sesiidae) . . . . . . . . . . 428

119. Carpenterworm, Prionoxystus robiniae (Peck.) (Lepidoptera: Cossidae) . . . . . . . . . . . . . . . . . 431

120. Pecan Carpenterworm, Cossula magnifica (Stecker) (Lepidoptera: Cossidae) . . . . . . . . . . . . 436

121. Spruce Budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae) . . . . . . . . . 439

122. Jack Pine Budworm, Choristoneura pinus pinus Freeman (Lepidoptera: Tortricidae) . . . . . . . . 445

123. Large Aspen Tortrix, Choristoneura conflictana (Walker) (Lepidoptera: Tortricidae) . . . . . . . . . 451

124. Sugar Pine Tortrix, Choristoneura lambertiana Busck (Lepidoptera: Tortricidae) . . . . . . . . . . . 456

125. Western Spruce Budworm, Choristoneura occidentalis Freeman 

 (Lepidoptera: Tortricidae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 460

126. Spruce Bud Moth, Zeiraphera canadensis Mutuura and Freeman 

 (Lepidoptera: Tortricidae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 466

127. Cottonwood Twig Borer, Gypsonoma haimbachiana (Kearfott) (Lepidoptera: Tortricidae) . . . . 469

129. Oak Leafroller, Archips semiferanus (Walker) (Lepidoptera: Tortricidae) . . . . . . . . . . . . . . . . . 473

130. Longleaf Pine Seedworm, Cydia ingens (Heinrich) (Lepidoptera: Tortricidae) . . . . . . . . . . . . . 475

131. European Pine Shoot Moth, Rhyacionia buoliana (Denis and Schiffermiiller) 

 (Lepidoptera: Tortricidae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 477

132. Nantucket Pine Tip Moth, Rhyacionia frustrana (Comstock) (Lepidoptera: Tortricidae) . . . . . . 482

133. Pitch Pine Tip Moth, Rhyacionia rigidana (Fernald) (Lepidoptera: Tortricidae) . . . . . . . . . . . . . 487

134. Southwestern Pine Tip Moth, Rhyacionia neomexicana (Dyar) (Lepidoptera: Tortricidae) . . . . 489

135. Eastern Pine Shoot Borer, Eucosma gloriola Heinrich (Lepidoptera: Tortricidae) . . . . . . . . . . . 491

136. Lodgepole Cone Moth, Eucosma rescissoriana Heinrich (Lepidoptera: Tortricidae) . . . . . . . . . 494

137. Western Pine Shoot Borer, Eucosma sonomana Kearfott (Lepidoptera: Tortricidae) . . . . . . . . 497

138. Douglas-fir Cone Moth, Barbara colfaxiana (Kearfott) (Lepidoptera: Tortricidae) . . . . . . . . . . . 500

139. Pine Webworm, Pococera robustella (Zeller) (Lepidoptera: Pyralidae) . . . . . . . . . . . . . . . . . . . 503

140. Zimmerman Pine Moth, Dioryctria zimmermani (Grote) (Lepidoptera: Pyralidae) . . . . . . . . . . 506

141. Fall Cankerworm, Alsophila pometaria (Harris) (Lepidoptera: Geometridae) . . . . . . . . . . . . . . 509

142. Spring Cankerworm, Paleacrita vernata (Peck) (Lepidoptera: Geometridae) . . . . . . . . . . . . . . 513

143. Eastern Hemlock Looper, Lambdina fiscellaria fiscellaria Guenée 

 (Lepidoptera: Geometridae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 516

144. Western Hemlock Looper, Lambdina fiscellaria lugubrosa (Hulst) 

 (Lepidoptera: Geometridae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 519

145. Greenstriped Forest Looper, Melanolophia imitata (Walker) (Lepidoptera: Geometridae) . . . . 522

146. Saddleback Looper, Ectropis crepuscularia (Denis and Schiffermüller) 

 (Lepidoptera: Geometridae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 524

147. Spearmarked Black Moth, Rheumaptera hastata (L.) (Lepidoptera: Geometridae) . . . . . . . . . 526

148. Elm Spanworm, Ennomos subsignarius (Hübner) (Lepidoptera: Geometridae) . . . . . . . . . . . . 529

Contents (continued)
149. Winter Moth, Operophtera brumata (L.) (Lepidoptera: Geometridae) . . . . . . . . . . . . . . . . . . . . 533

150. Bruce Spanworm, Operophtera bruceata (Hulst) (Lepidoptera: Geometridae) . . . . . . . . . . . . . 536

151. Forest Tent Caterpillar, Malacosoma disstria Hübner (Lepidoptera: Lasiocampidae) . . . . . . . . 538

152. Eastern Tent Caterpillar, Malacosoma americanum (F.) (Lepidoptera: Lasiocampidae) . . . . . . 543

153. Siberian Moth, Dendrolimus sibiricus TschetvericKov (Lepidoptera: Lasiocampidae) . . . . . . . 549

154. Pinkstriped Oakworm, Anisota virginiensis (Drury) (Lepidoptera: Saturniidae) . . . . . . . . . . . . . 553

155. Orangestriped Oakworm, Anisota senatoria (J. E. Smith) (Lepidoptera: Saturniidae) . . . . . . . 557

156. Pandora Moth, Coloradia pandora Blake (Lepidoptera: Saturniidae) . . . . . . . . . . . . . . . . . . . . 560

157. European Gypsy Moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae) . . . . . . . . . . . . . . . . 563

158. Asian Pink Moth, Lymantria mathura Moore (Lepidoptera: Lymantriidae) . . . . . . . . . . . . . . . . . 569

159. Nun Moth, Lymantria monacha Moore (Lepidoptera: Lymantriidae) . . . . . . . . . . . . . . . . . . . . . 573

160. Browntail Moth, Euproctis chrysorrhoea L. (Lepidoptera: Lymantriidae) . . . . . . . . . . . . . . . . . . 578

161. Pine Tussock Moth, Dasychira pinicola (Dyar) (Lepidoptera: Lymantriidae) . . . . . . . . . . . . . . . 583

162. Whitemarked Tussock Moth, Orgyia leucostigma (J. E. Smith) 

 (Lepidoptera: Lymantriidae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 586

163. Douglas-fir Tussock Moth, Orgyia pseudotsugata (McDunnough) 

 (Lepidoptera: Lymantriidae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 590

164. Poplar Tentmaker, Clostera inclusa (Hübner) (Lepidoptera: Notodontidae) . . . . . . . . . . . . . . . 594

165. Saddled Prominent, Heterocampa guttivitta (Walker) (Lepidoptera: Notodontidae) . . . . . . . . . 597

166. Walnut Caterpillar, Datana integerrima Grote and Robinson (Lepidoptera: Notodontidae) . . . . 600

167. Variable Oak Leaf Caterpillar, Lochmaeus manteo (Doubleday) 

 (Lepidoptera: Notodontidae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 605

168. Fall Webworm, Hyphantria cunea (Drury) (Lepidoptera: Arctiidae) . . . . . . . . . . . . . . . . . . . . . . 609

169. Arborvitae Leafminer, Argyresthia thuiella (Packard) (Lepidoptera: Argresthiidae) . . . . . . . . . . 614

170. Pine Needle Sheathminer, Zelleria haimbachi Busck (Lepidoptera: Yponomeutidae) . . . . . . . 618

171. Pine Butterfly, Neophasia menapia (Felder and Felder) (Lepidoptera: Pieridae) . . . . . . . . . . . 621

172. Balsam Gall Midge, Paradiplosis tumifex Gagné (Diptera: Cecidomyiidae) . . . . . . . . . . . . . . . 625

173. Poplar Leafcurl Midge, Prodiplosis morrisi Gagné (Diptera: Cecidomyiidae) . . . . . . . . . . . . . . 628

174. Douglas-fir Needle Midge, Contarinia pseudotsugae Condrashoff 

 (Diptera: Cecidomyiidae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 630

175. Pine False Webworm, Acantholyda erythrocephala (L.) (Hymenoptera: Pamphiliidae) . . . . . . 633

176. Redheaded Pine Sawfly, Neodiprion lecontei (Fitch) (Hymenoptera: Diprionidae) . . . . . . . . . . 637

177. Swaine Jack Pine Sawfly, Neodiprion swainei (Middleton) (Hymenoptera: Diprionidae) . . . . . 641

178. European Pine Sawfly, Neodiprion sertifer (Geoffroy) (Hymenoptera: Diprionidae) . . . . . . . . . 644

179. Virginia Pine Sawfly, Neodiprion pratti pratti (Dyar) (Hymenoptera: Diprionidae) . . . . . . . . . . . 648

180. Hemlock Sawfly, Neodiprion tsugae Middleton (Hymenoptera: Diprionidae) . . . . . . . . . . . . . . 651

Contents (continued)
181. Introduced Pine Sawfly, Diprion similis (Hartig) (Hymenoptera: Diprionidae) . . . . . . . . . . . . . . 655

182. European Spruce Sawfly, Gilpinia hercyniae (Hartig) (Hymenoptera: Diprionidae) . . . . . . . . . 659

183. Larch Sawfly, Pristiphora erichsonii (Hartig) (Hymenoptera: Tenthridinidae) . . . . . . . . . . . . . . 662

184. Mountain Ash Sawfly, Pristiphora geniculata (Hartig) (Hymenoptera: Tenthridinidae) . . . . . . . 666

185. Yellowheaded Spruce Sawfly, Pikonema alaskensis (Rohwer) 

 (Hymenoptera: Tenthredinidae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 669

186. Birch Leafminer, Fenusa pumila (Leach) (Hymenoptera: Tenthridinidae) . . . . . . . . . . . . . . . . . 673

187. Ambermarked Birch Leafminer, Profenusa thomsoni (Konow) 

 (Hymenoptera: Tenthridinidae) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 678

188. Sirex Woodwasp, Sirex noctilio (Fabricius) (Hymenoptera: Siricidae) . . . . . . . . . . . . . . . . . . . 682

189. Asian Chestnut Gall Wasp, Drycosmus kuriphilus Yasumatsu (Hymenoptera: Cynipidae) . . . . 689

190. Spruce Spider Mite, Oligonychus ununguis (Jacobi) (Acari: Tetranychidae) . . . . . . . . . . . . . . . 692

Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 697

Contents (continued)

A Photographic Guide 1

1. Pear Thrips, Taeniothrips inconsequences (Uzel) (Thysanoptera: 

Thripidae)

Orientation to Pest Pear thrips, Taeniothrips inconsequences (Uzel), is an invasive species 

in North America from Europe, first being recorded in the USA in 

California in 1900. Pear thrips have rasping/sucking mouthparts and use 

them to feed in early spring on buds and young leaves of hardwood trees. 

Potential for damage to sugar maples (Acer sacchrum Marshall) has been 

the greatest concern. Feeding injuries to embryonic or developing leaves 

result in mature leaves being deformed or tattered. Damage may spike in 

some years (e.g., the late 1980s) when thrips emerge earlier with respect 

to timing of bud break of key species, but such events are weatherdependent and do not occur regularly. In general the damage from this 

species is light.

Sugar maples (A. sacchrum Marshall) and other hardwoods.

No map available. The species is found in California, the northeast USA 

and southern Canada.

Hosts Commonly Attacked

Distribution

Images of Pear Thrips

Figure 1. Adult pear thrips, Taeniothrips inconsequences. (Left: Pennsylvania 

Department of Conservation and Natural Resources - Forestry Archive, 

Bugwood.org; right: Pennsylvania Bureau of Forestry)

Figure 2. Larva of pear thrips. (Pennsylvania Department of Conservation and 

Natural Resources - Forestry Archive, Bugwood.org)
2 Forest Pest Insects in North America:

Images of Pear Thrips

(continued)

Figure 3. Leaf deformities on sugar maple due to feeding of pear thrips on buds. 

(Left: Ronald S. Kelley, Vermont Department of Forests, Parks and Recreation, 

Bugwood.org; right: Margaret Miller-Weeks, USDA Forest Service)

No specialized natural enemies of this thrips are known and the minor 

and irregular damage caused by this pest suggests that it is best left 

unmanaged or controlled only on limited acreage with pesticides if need 

be in years of unusually high damage.

http://ento.psu.edu/extension/factsheets/pear-thrips-PA; bulletin from 

Pennsylvania State University on biology and control.

http://ecommons.cornell.edu/bitstream/1813/14346/2/Pear%20Thrips.

pdf; bulletin from Cornell University on biology and control.

http://www.na.fs.fed.us/spfo/pubs/pest_al/pt/pt.htm; bulletin of the 

United States Department of Agriculture.

http://www.onlinegardener.com/pests/Pear%20thrips.pdf; bulletin of 

Bartlett Tree Company on biology and control.

http://www.dec.ny.gov/docs/lands_forests_pdf/thrips.pdf; article from 

“New York Forest Owner” 1993 discussing impact of pear thrips on 

forests.

None

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Pear Thrips

Articles
A Photographic Guide 3

2. Introduced Basswood Thrips, Thrips calcaratus Uzel (Thysanoptera: 

Thripidae)

Orientation to Pest Introduced basswood thrips, Thrips calcaratus Uzel, is a European 

species invasive in eastern North America. Basswood thrips have 

rasping/sucking mouthparts and in early spring feed on buds, especially 

of American basswood (Tilia americana L.). Such bud-feeding causes 

mature leaves to be deformed or tattered and defoliation may occur. 

Repeated defoliation of American basswood reduces tree growth 

and increases rates of dieback from other causes. The species is of 

importance in northern Wisconsin, where outbreaks of damage occur.

In North America, this species feeds on American basswood 

(T. americana). 

The species is found in New England and Quebec, westward through 

Ontario, Pennsylvania, New York, and the Great Lake States.

Hosts Commonly Attacked

Distribution

Images of Introduced

Basswood Thrips

Figure 1. Adult of introduced basswood thrips, Thrips calcaratus. (Kenneth Raffa, 

University of Wisconsin, Bugwood.org)

Figure 2. Larva of introduced basswood thrips. (Kenneth Raffa, University of 

Wisconsin, Bugwood.org)
4 Forest Pest Insects in North America:

Images of Introduced

Basswood Thrips (continued)

Figure 3. Typical damage to basswood buds from thrips feeding (here by another 

thrips, Neohydratothrips tiliae [Hood]). (Steven Katovich, USDA Forest Service, 

Bugwood.org)

No specialized natural enemies of this thrips are known.

http://www.na.fs.fed.us/spfo/pubs/howtos/ht_bassthrips/ht_bassthrips.

htm; USDA Bulletin on biology of introduced basswood thrips.

Figure 4. Defoliation of American basswood by introduced basswood thrips. 

(Steven Katovich, USDA Forest Service, Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Introduced Basswood 

Thrips
A Photographic Guide 5

Raffa, K.F. and D.J. Hall. 1988. Thrips calcaratus Uzel (Thysanoptera: 

Thripidae), a new pest of basswood trees in the Great Lakes region. 

Canadian Journal of Forest Research 19: 1662-1663. 

Raffa, K.F. 1991. Biology and impact of Thrips calcaratus Uzel in the 

Great Lakes region. In: Parker, B.L., M. Skinner, and T. Lewis (eds.). 

Towards Understanding Thysanoptera. USDA Forest Service General 

Technical Report NE-147: 317-324. 

Werner, S.M., M.A. Albers, T. Cryderman, D. Diminic, R. Heyd, B. 

Hrašovic, S. Kobro, S. Larsson, R. Mech, P. Niemela, M. Rousi, K.F. 

Raffa, K. Scanlon, and S. Weber. 2006. Is the outbreak status of Thrips 

calcaratus Uzel in North America due to altered host relationships? 

Forest Ecology and Management 225: 200-206.

Articles
6 Forest Pest Insects in North America:

3. Redbanded Thrips, Selenothrips rubrocinctus (Giard) (Thysanoptera: 

Thripidae)

Orientation to Pest Redbanded thrips, Selenothrips rubocinctus (Giard), is an invasive 

polyphagous tropical thrips of Asian origin found in Hawaii, Florida, 

and Puerto Rico. A sucking/rasping insect, its damage is similar in some 

regards to that of mite damage on foliage, consisting of a mixture of 

discolored areas and the dark areas that result from the liquid deposited 

where eggs are inserted in plant tissues. Affected leaves may be distorted 

or may drop from plant. Dense thrips populations may defoliate plants. 

Thrips also produce honeydew, which leads to growth of sooty molds.

Hosts of redbanded thrips include various fruits (cashew, grape, mango, 

avocado, guava), ornamentals, and shade trees.

Redbanded thrips is found in Hawaii, Florida, and Puerto Rico.

Hosts Commonly Attacked

Distribution

Images of 

Redbanded Thrips

Figure 1. Adult of redbanded thrips, Selenothrips rubocinctus. (Lyle Buss, 

University of Florida, Bugwood.org)

Figure 2. Pupae of redbanded thrips. (Lyle Buss, University of Florida, 

Bugwood.org)
A Photographic Guide 7

Figure 4. Damage of 

redbanded thrips on 

mango. (Scot Nelson, 

University of Hawaii at 

Manoa, Bugwood.org)

Figure 3. Damage by redbanded thrips. (James L. Castner, University of Florida)

Images of Redbanded 

Thrips (continued)

Goetheana shakespearei Girault is a self-introduced eulophid parasitoid 

of redbanded thrips found in Florida since 1992, originally detected 

in a greenhouse. The same parasitoid under the name Dasyscapus 

parvipennis was shipped from Trinidad to Puerto Rico in the 1930s and 

established. In Australia, a weaver ant is cited as of importance, while in 

South Africa, a species of predatory bug (Orius thripoborus [Hesse]) has 

been noted as a predator of this thrips. 

Important Biological Control 

Agents Related to this 

Pest Species
8 Forest Pest Insects in North America:

Web Links for Information 

on Redbanded Thrips

http://edis.ifas.ufl.edu/pdffiles/IN/IN25600.pdf; University of Florida 

factsheet.

https://transact.nt.gov.au/ebiz/dbird/TechPublications.nsf/

56FBE080115393C669256EFF004B540D/$file/752.pdf; an Australian 

bulletin on redbanded thrips.

Dennill, G.B. 1992. Orius thripoborus (Anthocoridae), a potential 

biocontrol agent of Heliothrips haemorrhoidalis and Selenothrips 

rubrocinctus (Thripidae) on avocado fruits in the eastern Transvaal. 

Journal of the Entomological Society of Southern Africa 55(2): 255-258.

Bennett, F.D., H.A. Glenn, and R.M. Baranowski. 1993. Goetheana 

shakespearei (Hymenoptera: Eulophidae) an immigrant parasitoid of 

thrips in Florida and Guadeloupe. Florida Entomologist 76: 395-397.

Peng, R.K. and K. Christian. 2004 The weaver ant, Oecophylla 

smaragdina (Hymenoptera: Formicidae), an effective biological control 

agent of the red-banded thrips, Selenothrips rubrocinctus (Thysanoptera: 

Thripidae) in mango crops in the Northern Territory of Australia. 

International Journal of Pest Management 50(2): 107-114. 

Articles
A Photographic Guide 9

4. Slash Pine Flower Thrips, Gnophothrips fuscus (Morgan) (Thysanoptera: 

Phlaeothripidae)

The biology of slash pine flower thrips, Gnophothrips fuscus (Morgan), 

is poorly known. It is assumed to be widespread throughout the eastern 

United States but has only been of concern in seed orchards of slash pine 

(Pinus elliottii var. elliottii Engelm.), where feeding on female cones 

destroys about a quarter of the potential seed set. 

The principal hosts are slash (P. elliottii var. elliottii), jack (P. banksiana

Lamb.), and loblolly (P. taeda L.) pines. 

Slash pine flower thrips is found in the southeastern United States, from 

Florida to east Texas, north to Ohio and Maryland. 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Figure 1. U.S. distribution of slash 

pine flower thrips, Gnophothrips 

fuscus. (USDA Forest Service, “Seed 

and Cone Insects of Southern Pines”)

Figure 2. Slash pine flower thrips. (István Mikó and the NCSU Insect Museum)

Images of Slash Pine

Flower Thrips
10 Forest Pest Insects in North America:

Images of Slash Pine

Flower Thrips (continued)

Figure 3. Young female slash pine cone showing damage from slash pine flower 

thrips. (Bernard H. Ebel, USDA Forest Service, Bugwood.org)

Figure 4. Damage of slash pine 

flower thrips as seen in mature cones. 

(USDA Forest Service, “Seed and 

Cone Insects of Southern Pines”)

Nothing is known about specialized natural enemies of this species.

http://216.166.86.145/pubs/seed-and-cone/page7.html; USDA Forest 

Service bulletin “Seed and cone insects of southern pines.”

Fatzinger, C.W. and W.N. Dixon. 1991. Development of sampling 

methods for the slash pine flower thrips, Gnophothrips fuscus (Morgan) 

(Thysanoptera: Phlaeothripidae). In: Parker, B.L., M. Skinner, and T. 

Lewis (eds.). Towards Understanding Thysanoptera. USDA Forest 

Service General Technical Report NE-147: 149-161.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Slash Pine Flower Thrips

Articles
A Photographic Guide 11

5. Northern Walkingstick, Diapheromera femorata (Say) (Phasmatodea: 

Heteronemiidae)

Orientation to Pest The northern walkingstick, Diapheromera femorata (Say), is the only 

walkingstick of economic importance in the USA. While young nymphs 

feed on shrubs of various species, older nymphs and adults feed on 

leaves of a wide variety of hardwood trees. Populations at times are 

dense enough to completely defoliate affected trees. Eggs fall from 

trees and when populations are dense, sounds of falling eggs are readily 

noticed. Overwintering occurs in the egg stage.

Species fed on by the northern walkingstick include black (Quercus

velutina Lamb.) and red (Q. rubra L.) oaks, American basswood (Tilia 

americana L.), American elm (Ulmus americana L.), black locust 

(Robinia pseudoacacia L.), cherry (Prunus spp.), and other hardwoods.

This walkingstick is found in southern Canada and most of the eastern 

United States, west to Texas and the Great Plains. 

Hosts Commonly Attacked

Distribution

Images of 

Northern Walkingstick

Figure 1. Adult of the northern walkingstick, Diapheromera femorata. (Kenneth 

Raffa, University of Wisconsin, Bugwood.org)
12 Forest Pest Insects in North America:

Images of Northern 

Walkingstick (continued)

Figure 2. Mating 

pair of the northern 

walkingstick; small 

male mounted on large 

female. (Kenneth Raffa, 

University of Wisconsin, 

Bugwood.org)

Figure 3. Seed-like eggs of the northern walkingstick being examined by an ant. 

(Photo copyright Alex Wild/alexanderwild.com)
A Photographic Guide 13

Images of Northern 

Walkingstick (continued)

Figure 4. Oak foliage showing feeding of the walkingstick. (Both photosl: James 

Solomon, USDA Forest Service, Bugwood.org)

Figure 5. Forest in Mena, Arizona partially defoliated by the walkingstick. (James 

Solomon, USDA Forest Service, Bugwood.org)
14 Forest Pest Insects in North America:

The parasitoid Mesitiopterus kahlii (Ashmead) (Hymenoptera: 

Chrysididae) attacks the D. femorata. Also, birds can feed heavily on 

walkingsticks when their population densities are high.

http://wiki.bugwood.org/Archive:South/Walkingstick

http://www.na.fs.fed.us/spfo/pubs/fidls/walkingstick/walkingstick.htm; 

Forest Insect & Disease Leaflet 82, U.S. Department of Agriculture, 

Forest Service.

Ignoffo, C.M., D.L. Hostetter, and W.H. Kearby. 1973. Susceptibility of 

walkingstick, orangestriped oakworm, and variable oakleaf caterpillar to 

Bacillus thuringiensis var. alesti. Environmental Entomology 2: 807-809.

Giese, R.L. and K.H. Knauer. 1977. Ecology of the walkingstick. Forest 

Science 23: 45-63.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Northern Walkingstick

Articles
A Photographic Guide 15

6. Oak Lace Bug, Corythucha arcuata (Say) (Hemiptera: Tingidae)

Oak lace bug, Corythucha arcuata (Say), is a minor pest of various oaks 

in its native range in North America. The insect may overwinter as either 

adults or eggs. Adults have lacey wings held flat over the body with an 

ornate pronotum. Nymphs are mostly black with spines. Feeding begins 

in early spring at leaf expansion. Eggs are laid on the underside of leaves. 

Nymphs and adults occur in colonies on foliage where they feed by 

sucking sap from plant tissues. Damage is similar to the yellow stippling 

produced by spider mite feeding, but without webbing. Black fecal spots 

are also present on foliage infested by lace bugs. Dense populations can 

cause premature leaf drop. There are multiple generations per year.

The main hosts of this species are white (Quercus alba L.), bur (Q. 

macrocarpa Michx.), and chestnut oaks (Q. prinus L.). 

This bug occurs from Alabama and the Carolinas north to southern 

Canada. 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of Oak Lace Bug

Figure 1. Adult of oak lace bug, Corythucha arcuata. (Joseph Berger, 

Bugwood.org)
16 Forest Pest Insects in North America:

Images of Oak Lace Bug

(continued)

Figure 3. Oak foliage showing damage (yellow stippling) on the upper leaf 

surface from feeding of oak lace bug. (Jim Baker, North Carolina State University, 

Bugwood.org)

Figure 2. Nymphs of oak lace bug on underside of oak leaf. (Jim Baker, North 

Carolina State University, Bugwood.org)

Little is known of the specific natural enemies of the oak lace bug. One 

generalist predator associated with the species is the mirid Deraeocoris 

nebulosus (Uhler).

http://www.fs.fed.us/r8/foresthealth/pubs/oakpests/p30.html

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Oak Lace Bug
A Photographic Guide 17

Horn, K.F., C.G. Wright, and M.H. Farrier. 1979. The lace bugs 

(Hemiptera: Tingidae) of North Carolina and their hosts. North Carolina 

Agricultural Experiment Station Technical Bulletin No. 257: 22 p.

Wheeler, A.G., Jr., B.R. Stinner, and T.J. Henry. 1975. Biology and 

nymphal stages of Deraeocoris nebulosus (Hemiptera: Miridae), a 

predator of arthropod pests on ornamentals. Annals of the Entomological 

Society of America 68: 1063-1068.

Articles
18 Forest Pest Insects in North America:

7. Sycamore Lace Bug, Corythucha ciliata (Say) (Hemiptera: Tingidae)

Sycamore lace bug, Corythucha ciliata (Say), is a minor pest of 

American sycamore (Planatus occidentalis L.) in its native range in 

North America but is very important in Europe as an invasive species 

on urban plane trees. It has also invaded Australia, China, Turkey, and 

Chile. Adults overwinter under the bark flakes of sycamores. Feeding 

activity begins in early spring at leaf expansion of host plants. Eggs are 

laid on the underside of leaves. Nymphs and adults occur in colonies 

on the underside of foliage where they feed by sucking sap from plant 

cells. Feeding by low densities of lace bugs results in yellow stippling, 

starting along the mid-veins, similar in appearance to the damage caused 

by spider mites, but without webbing. Black fecal spots are also present 

on the undersides of leaves infested by lace bugs. Dense populations can 

cause a white or bronzed appearance to the leaves and premature leaf 

drop. In the northeast United States, there are two to four generations 

per year.

The principal host of sycamore lace bug is American sycamore 

(P. occidentalis), but it occasionally feeds on ash (Fraxinus), hickory 

(Carya), and mulberry (Morus).

This bug is native throughout the eastern USA and southern Canada. It 

is also invasive in Europe, Turkey, Australia, China, and Chile. Spread 

is likely due to tendency of adults to secrete themselves into crevices 

for overwintering, allowing them to be easily moved in crates or cargo 

between countries. 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of 

Sycamore Lace Bug

Figure 1. Adult of sycamore lace bug, Corythucha ciliate. (Louis-Michel 

Nageleisen, Département de la Santé des Forêts, Bugwood.org)
A Photographic Guide 19

Images of Sycamore 

Lace Bug (continued)

Figure 2. Adults of sycamore lace bug feed in groups on the undersides of 

leaves (note the black fecal spots). (Jim Baker, North Carolina State University, 

Bugwood.org)

Figure 3. Nymphs of sycamore lace bug. (James Solomon, USDA Forest Service, 

Bugwood.org)

Figure 4. Size of mature nymphs of sycamore lace bug (black, on left) as 

compared to adults. (Steven Katovich, USDA Forest Service, Bugwood.org)
20 Forest Pest Insects in North America:

Images of Sycamore 

Lace Bug (continued)

Figure 5. Close up showing the black fecal spots deposited by sycamore lace bug. 

(Bruce W. Kauffman, Tennessee Department of Agriculture, Bugwood.org)

Figure 6. Yellow stippling and bronzing of foliage caused by sycamore lace bug. 

(Whitney Cranshaw, Colorado State University, Bugwood.org)

Figure 7. Sycamore trees bronzed by feeding of sycamore lace bug. 

(Terry S. Price, Georgia Forestry Commission, Bugwood.org)
A Photographic Guide 21

Little is known of the specific natural enemies of the sycamore lace bug. 

The generalist predatory mirid Deraeocoris nebulosus (Uhler) is known 

to feed on sycamore lace bugs.

http://entnemdept.ufl.edu/creatures/trees/sycamore_lace_bug.htm; fact 

sheet of the University of Florida.

Halbert, S.E. and J.R. Meeker. 1998. The Sycamore Lace Bug, 

Corythucha ciliata (Say) (Hemiptera: Tingidae). Entomology Circular 

No.387. Florida Dept. Agric. & Consumer Services, Division of Plant 

Industry. (Available at http://www.fl-dof.com/publications/fh_pdfs/

Sycamore%20Lace%20Bug.pdf). 

Wheeler, A.G., Jr., B.R. Stinner, and T.J. Henry. 1975. Biology and 

nymphal stages of Deraeocoris nebulosus (Hemiptera: Miridae), a 

predator of arthropod pests on ornamentals. Annals of the Entomological 

Society of America 68: 1063-1068.

Horn, K.F., C.G. Wright, and M.H. Farrier. 1979. The lace bugs 

(Hemiptera: Tingidae) of North Carolina and their hosts. North Carolina 

Agricultural Experiment Station Technical Bulletin No. 257: 22 p.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Sycamore Lace Bug

Articles
22 Forest Pest Insects in North America:

8. Shield-backed Pine Seed Bug, Tetyra bipunctata (Herrich-Schäffer) 

(Hemiptera: Scutellaridae)

The shield-backed pine seed bug, Tetyra bipunctata (Herrich-Schäffer), 

feeds on seeds in cones of various pines and thus causes losses in seed 

orchards. There is one generation a year, and nymphs and adults feed in 

groups. Most damage to seeds is done in late summer or fall and is not 

visible, even after the seeds have been extracted from cones. 

This insect feeds on various pines, including loblolly (Pinus taeda L.), 

slash (Pinus elliottii Engelm.), shortleaf (Pinus echinata Mill.), Virginia 

(Pinus virginiana Mill.), eastern white (Pinus strobus L.), red (Pinus 

resinosa Sol. ex Aiton), jack (Pinus banksiana Lamb.), and sand (Pinus 

clausa [Chapm. ex Engelm.] Sarg.) pines.

The shield-backed pine seed bug occurs from Virginia north to Ontario 

and Quebec and west to Minnesota and Oklahoma. 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of the

Shield-backed Pine Seed Bug

Figure 1. Adult shieldbacked pine seed bug, 

Tetyra bipunctata. 

(John Maxwell, Marlton, NJ, 

USA, Bugguide.net)

Figure 2. Eggs of shieldbacked pine seed bug. 

(Texas Forest Service 

Archive, Texas Forest 

Service, Bugwood.org)
A Photographic Guide 23

Figure 3. Nymph of shield-backed pine seed bug. (USDA Forest Service - 

Northeastern Area Archive, USDA Forest Service, Bugwood.org)

Figure 4. Shield-backed pine seed bug adults feeding on cones. (Larry R. Barber, 

USDA Forest Service, Bugwood.org)

Images of the Shield-backed 

Pine Seed Bug (continued)

Specific natural enemies of this species are unknown.

http://www.forestpests.org/nursery/seedandcone.html; fact sheet “Seed 

and Cone Insects” by Larry R. Barber, Entomologist, Region 8, USDA 

Forest Service, Asheville, North Carolina.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Shield-backed 

Pine Seed Bug
24 Forest Pest Insects in North America:

Articles on Shield-backed

Pine Seed Bug

DeBarr, G.L. 1979. Importance of the seedbugs Leptoglossus corculus

(Say) (Hemiptera: Coreidae) and Tetyra bipunctata (H.-S.) (Hemiptera: 

Pentatomidae) and their control in southern pine seed orchards. 

Proceedings: a symposium on flowering and seed development in trees. 

Starkville, Mississippi: Southern Forest Experiment Station: 330-341.

Gilbert, B.L., S.J. Barras, and D.M. Norris. 1967. Bionomics of Tetyra 

bipunctata (Hemiptera: Pentatomidae: Scutellerinae) as associated with 

Pinus banksiana in Wisconsin. Annals of the Entomological Society of 

America 60: 698-701.

Goyer, R.A. and V.G. Williams.1981. The effects of feeding by 

Leptoglossus corculus (Say) and Tetyra bipunctata (Herrich and 

Schaffer) on loblolly pine (Pinus taeda L.) conelets. Journal of Georgia 

Entomological Society 16: 16-21.

Turgeon, J.J., P. de Groot, and J.D. Sweeney. 2005. Insects of seed cones 

in eastern Canada; field guide. Ontario Ministry of Natural Resources/

Forestry Canada, Toronto: 127 p.
A Photographic Guide 25

9. Leaffooted Pine Seed Bug, Leptoglossus corculus (Say) (Hemiptera: 

Coreidae)

The leaffooted pine seed bug, Leptoglossus corculus (Say), is a sucking 

insect that damages cones in pine seed orchards in the southern United 

States. Both adults and nymphs fed on seeds in cones of various pines, 

greatly reducing production of viable seed. There are several generations 

per year in the southern United States. 

The leaffooted pine seed bug commonly attacks cones of loblolly 

(Pinus taeda L.), slash (P. elliottii Engelm.), shortleaf (P. echinata Mill.), 

Virginia (P. virginiana Mill.), eastern white (P. strobus L.), pitch 

(P. rigida Mill.) and Table Mountain (P. pungens Lamb.) pines, as well 

as cones of some spruce (Picea).

The leaffooted pine seed bug occurs throughout the eastern United 

States.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of 

Leaffooted Pine Seed Bug

Figure 2. String of eggs of leaffooted pine seed bug. (Lacy L. Hyche, Auburn 

University, Bugwood.org)

Figure 1. Adult leaffooted pine seed bug, Leptoglossus corculus. See the flat, 

expanded lower section of hind legs. (R. Scott Cameron, Advanced Forest 

Protection, Inc., Bugwood.org) 
26 Forest Pest Insects in North America:

Images of Leaffooted 

Pine Seed Bug (continued)

Figure 3. Nymph of leaffooted pine seed bug. (Tim Tigner, Virginia Department of 

Forestry, Bugwood.org)

The parasitoid Ooencyrtus leptoglossi Yoshimoto is known to attack the 

eggs of this species. 

http://www.forestpests.org/nursery/seedandcone.html; fact sheet “Seed 

and Cone Insects” by Larry R. Barber, Entomologist, Region 8, USDA 

Forest Service, Asheville, North Carolina.

DeBarr, G.L. 1979. Importance of the seedbugs Leptoglossus corculus

(Say) (Hemiptera: Coreidae) and Tetyra bipunctata (H.-S.) (Hemiptera: 

Pentatomidae) and their control in southern pine seed orchards. 

Proceedings: a symposium on flowering and seed development in trees. 

Starkville, Mississippi. Southern Forest Experiment Station: 330-341.

Figure 4. Leaffooted pine seed bug adult feeding on immature cone of pine. 

(Larry R. Barber, USDA Forest Service, Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Leaffooted Pine Seed Bug

Articles
A Photographic Guide 27

10. Royal Palm Bug, Xylastodoris luteolus Barber (Hemiptera: 

Thaumastocoridae)

Royal palm bug, Xylastodoris luteolus Barber, is a sucking bug that feeds 

on immature leaves of royal palm (Roystonea regia [Kunth] O.F. Cook). 

If densities are high, this feeding may cause browning of affected foliage.

This sucking bug feeds on royal palm (R. regia), sometimes called 

Florida royal palm or Cuban royal palm.

This insect’s native range is Cuba, but it also occurs in southern Florida.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of 

Royal Palm Bug

Figure 1. Adults of royal palm bug, Xylastodoris luteolus. (Lyle Buss, University of 

Florida, Bugwood.org)

Figure 2. Close view of damage to Florida royal palms by the royal palm bug. 

(Doug Caldwell, University of Florida, Bugwood.org)
28 Forest Pest Insects in North America:

Images of Royal 

Palm Bug (continued)

Figure 3. Damage to Florida 

royal palm frond by the royal 

palm bug. (Doug Caldwell, 

University of Florida, 

Bugwood.org)

Figure 4. Whole tree view of damage to Florida royal palm frond by the 

royal palm bug. (Both photos: Dr. A. D. Ali, Davey Tree Expert Company, 

Bugwood.org)

Specialized natural enemies of this species are unknown. 

http://entnemdept.ufl.edu/creatures/orn/palms/royal_palm_bug.htm

http://edis.ifas.ufl.edu/in254; fact sheet of University of Florida IFAS 

Extension.

Weissling, T.J., F.W. Howard, and A.W. Meerow. Royal palm bug, 

Xylastodoris luteolus Barber (Insecta: Hemiptera: Thaumastocoridae). 

EENY-097 University of Florida IFAS Extension. (Available at http://

edis.ifas.ufl.edu/in254).

Ali, A.D. and D. Caldwell. 2010. Royal palm bug Xylastodoris luteolus

(Hemiptera: Thaumastocoridae) control with soil-applied systemics. 

Florida Entomologist 93: 294-297. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Royal Palm Bug

Articles
A Photographic Guide 29

Figure 1a. Adults of Saratoga spittlebug, Aphrophora saratogensis. 

(Pennsylvania Department of Conservation and Natural Resources - Forestry 

Archive, Bugwood.org)

11. Saratoga Spittlebug, Aphrophora saratogensis (Fitch) (Hemiptera: 

Cercopidae)

Orientation to Pest Saratoga spittlebug, Aphrophora saratogensis (Fitch), is a native insect 

in North America whose adults damage certain pines, especially red 

pine (Pinus resinosa Sol. ex Aiton), usually when grown in plantations. 

Damage also occurs on jack (P. banksiana Lamb.) and Scots pines 

(P. sylvestris L.). Adult feeding damages pines because toxics injected 

into the plant kill tissues, causing dead pockets of xylem and phloem 

tissue. Extensive feeding kills branches, stunts and deforms shoots, 

and may sometimes kill trees. This species is generally considered 

the most serious sap-feeding pest of red pine plantations. In contrast, 

nymphs are not pests because they feed on different plants. Young 

nymphs feed on understory plants such as brambles (species of Rubus), 

orange hawkweed (Pilosella aurantiaca [L.] F.W. Schultz and SchultzBip), pearly everlasting (Anaphalis nubigena DC.), and asters (Aster), 

while older nymphs are found on sweetfern (Comptonia peregrine [L.] 

J.M. Coulter) and young willows (Salix). Saratoga spittlebug has one 

generation each year. On red pine, eggs are laid under the outer scales of 

buds in the upper branches. Selection criteria have been developed that 

use information on nymphal host plant abundance to pick sites for new 

red pine plantations that will have low risk of damage from Saratoga 

spittlebug. A site-risk diagram has been developed for this purpose (see 

figure in USDA Forest Service leaflet at http://www.na.fs.fed.us/spfo/

pubs/fidls/saratoga/saratoga.htm).

Saratoga spittlebug is known as a pest of some pines, especially red pine 

(P. resinosa) grown in plantations.

This insect occurs where ever its hosts grow, from Maine to Minnesota in 

the United States and in the southern portions of the adjacent Canadian 

Provinces. It is of particular importance in Michigan and Wisconsin.

Hosts Commonly Attacked

Distribution

Images of 

Saratoga Spittlebug
30 Forest Pest Insects in North America:

Figure 1b. Adult Saratoga 

spittlebug, Aphrophora 

saratogensis. (Tom Murray)

Figure 2. Eggs of Saratoga spittlebug (dark bodies in woolly mass). 

(James B. Hanson, USDA Forest Service, Bugwood.org)

Figure 3. Spittle masses of Saratoga spittlebugs at base of stems of sweetfern, 

the favorite host of older nymphs. (Linda Haugen, USDA Forest Service, 

Bugwood.org)

Images of Saratoga 

Spittlebug (continued)
A Photographic Guide 31

Figure 4. Saratoga spittlebug feeding damage to red pine (Both photos: USDA 

Forest Service - Northeastern Area Archive, USDA Forest Service, Bugwood.org)

Images of Saratoga 

Spittlebug (continued)

Eggs of Saratoga spittlebug are attacked by two parasitoids, Ooctonus

aphrophorae Milliron and Tumidiscapus cercopiphagus Milliron, but 

attack rates are low (<5 percent). A fly in the family Pipunculidae, 

Verrallia virginica Banks, may be a significant source of mortality 

(causing up to 50 percent mortality). 

http://www.na.fs.fed.us/spfo/pubs/fidls/saratoga/saratoga.htm; a USDA 

Forest Service pest leaflet.

http://www.maine.gov/doc/mfs/saratoga.htm; Maine fact sheet.

Wilson, L.F. 1971. Risk-rating Saratoga spittlebug damage by abundance 

of alternate-host plants. Research Note NC-110, North Central Forest 

Experiment Station, Forest Service, United States Department of 

Agriculture: 4 p.

Linnane, J.P. and E.A. Osgood. 1977. Verrallia virginica (Diptera: 

Pipunculidae) reared from the Saratoga spittlebug in Maine. Proceedings 

of the Entomological Society of Washington 79(4): 622-623.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Saratoga Spittlebug

Articles
32 Forest Pest Insects in North America:

12. Pine Spittlebug, Aphrophora parallela (Say) (Hemiptera: Cercopidae)

Pine spittlebug, Aphrophora parallela (Say), is a native insect in North 

America that is found in most of the eastern United States and adjacent 

southern Canada. Adults and nymphs develop on the same plant species. 

The most favored host is Scots pine (Pinus sylvestris L.). Eggs are 

deposited under bark and are the overwintering stage. Nymphs initially 

feed on twigs, but later move to the trunk, forming protective spittle 

masses each time they move. Adults return to twigs to feed. There is 

a single generation per year. Feeding of this spittlebug promotes the 

spread of a pathogenic fungus, Sphaeropsis sapinea (synonyms S. ellisii

and Diplodia pinea), which invades weakened trees through spittlebug 

feeding punctures. This fungus is responsible for a considerable part of 

the dead branches associated with this insect.

Pine spittlebugs seem to prefer Scots pine but are also found on six 

other pines, three species of spruce (Picea), balsam fir (Abies balsamea

[L.] Miller), larch (Larix), and eastern hemlock (Tsuga canadensis (L.) 

Carrière).

Pine spittlebug is found throughout the eastern United States and 

adjacent parts of southern Canada.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of Pine

Spittlebug

Figure 1. Adult of pine spittlebug, Aphrophora parallela. (Lacy L. Hyche, Auburn 

University, Bugwood.org)

Figure 2. Spittle mass pushed aside to show nymph of pine spittlebug. 

(Lacy L. Hyche, Auburn University, Bugwood.org)
A Photographic Guide 33

The fungus Entomophora aphrophorae Rostrup at times causes high 

mortality to nymphs. 

http://wiki.bugwood.org/Aphrophora_parallela; short fact sheet by 

BugwoodWiki.

http://www.entomology.umn.edu/cues/Web/199Spittlebugs.pdf; fact 

sheet with a comparison among spittlebug species.

http://ipm.illinois.edu/diseases/rpds/625.pdf; report on Sphaeropsis blight 

or Diplodia tipblight of pines. 

http://www.maine.gov/doc/mfs/pinespit.htm; Maine government fact 

sheet.

Wilson, L.F. and D.G. Mosher. 1981. How to identify and control pine 

spittlebug [Aphrophora parallela]. North Central Forest Experiment 

Station, USDA Forest Service, St. Paul, Minnesota: 6 p. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Pine Spittlebug

Articles
34 Forest Pest Insects in North America:

13. Thorn Bug, Umbonia crassicornis (Amyot and Serville) (Hemiptera: 

Membracidae)

Orientation to Pest The thorn bug Umbonia crassicornis (Amyot and Serville) is a sucking 

bug that is an occasional pest of ornamentals and fruit trees in southern 

Florida. Colonies of these insects may be very visible on the twigs of 

their hosts. Feeding may lead to defoliation or twig death in some species 

of plants. Also, thorn bugs produce honeydew, which leads to growth of 

sooty mold. Eggs are laid in bark of tender twigs and, most interestingly 

for insects, females show maternal care by actively tending their 

offspring. Young nymphs have three horns instead of the one seen on the 

adults. Colonies of insects are chemically defended against predators. 

Among plants that suffer important injury when infested with thorn bugs 

are species of Hibiscus, powder-puff (Calliandra), woman’s tongue 

tree (Albizzia lebbek [L.] Benth.), and species of Acacia. Other hosts 

suitable for reproduction include wild tamarind (Lysiloma bahamensis), 

tamarind (Tamarindus indica L.), Casuarina sp., Crotalaria sp., rayado 

bundleflower (Desmanthus virgatus Benth.), bottle brush (Callistemon

sp.), Jerusalem thorn (Parkinsonia aculeate L.), and dwarf date palm 

(Phoenix roebelenii O’Brien). 

This thorn bug is subtropical or tropical and found in Mexico, Central 

and South America. In the United States, it is found only in southern and 

central Florida. 

Hosts Commonly Attacked

Distribution

Images of Thorn Bug

Figure 1. Adult of the thorn bug Umbonia crassicornis. (Lyle Buss, University of 

Florida, Bugwood.org)
A Photographic Guide 35

Images of Thorn Bug

(continued)

Figure 2. Adults of this thorn bug are variable in terms of the shape and size of 

their horn. (Lyle Buss, University of Florida, Bugwood.org)

No information is available on specialized natural enemies of this 

species.

http://edis.ifas.ufl.edu/pdffiles/IN/IN33200.pdf; fact sheet of the 

University of Florida.

Wood, T.K. 1976. Alarm behavior of brooding female Umbonia 

crassicornis (Homoptera: Membracidae). Annals of the Entomological 

Society of America 69: 340-344.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Thorn Bug

Articles
36 Forest Pest Insects in North America:

14. Periodical Cicada, Magicicada septendecim L. (Hemiptera: Cicadidae)

The periodical cicada, Magicicada septendecim L., is the largest of 

periodically emerging cicada species (adult, 40 mm in length). Females 

are black on top and males are black with a pattern of 4 or 5 orangebrown abdominal segments when viewed from below. The female has a 

stout ovipositor that is used to insert eggs into the bark of small branches 

and twigs. Eggs are laid in batches of 25-30, and many batches may 

be laid in the same twig. After eggs hatch, nymphs drop to the ground 

and burrow into the soil, where they feed on the plant’s roots. Nymphs 

require 17 years to complete their development. Emergence of last instar 

nymphs is synchronous, producing mass swarms of adults at 17-year 

intervals. Broods (populations in different areas) are not necessarily in 

synchrony. Effect of nymphal feeding on roots has not been quantified. 

The only significant injury caused by this insect is the dieback of small 

branches (“flagging”) from the cuts made for oviposition. While this 

injury can be highly visible it is not harmful to larger trees and shrubs 

since it only occurs every 17 years and large plants can tolerate this level 

of damage. On smaller trees, however, extensive oviposition may be 

harmful. Homeowners who need to protect small trees and shrubs from 

damage can do so by covering plants with netting to exclude cicadas, 

which should be left in place until most cicadas have died off (about 

four weeks from their first appearance). Periodical cicadas are often 

too numerous to make applications of pesticides practical. The mass 

emergences of this insect are much appreciated as a wildlife phenomenon 

and this species is best viewed as an impressive act of nature rather than 

as a pest. 

This cicada lays its eggs in more than 70 species of trees or other 

plants, but the most affected trees are oaks (Quercus), hickory (Carya), 

honeylocust (Gleditsia triacanthos L.), dogwood (Cornus), apple (Malus

domestica Borkh.), and peach (Prunus persica [L.] Batsch.). But many 

other species may also be attacked at times. 

Magicicada septendecim is widely distributed in the eastern United 

States.

Orientation to Pest

Hosts Commonly Attacked

Distribution
A Photographic Guide 37

Images of the

Periodical Cicada

Figure 2. Oviposition scars made by the periodical cicada in a branch. 

(John H. Ghent, USDA Forest Service, Bugwood.org)

Figure 3. Nymph of periodical cicada, the below-ground life stage. (Bill Gallup, 

Bugwood.org)

Figure 1. Adult of the periodical cicada, Magicicada septendecim, a 17-yr cicada. 

(John H. Ghent, USDA Forest Service, Bugwood.org)
38 Forest Pest Insects in North America:

Images of the Periodical 

Cicada (continued)

Figure 4. Holes in soil made by emerging last instar nymphs of the periodical 

cicada. (Jim Occi, BugPics, Bugwood.org)

Figure 5. Adult of a periodical cicada as it begins to molt from the last nymphal 

instar after its emergence from the soil. (John H. Ghent, USDA Forest Service, 

Bugwood.org)

Figure 6. Cast skins of periodical cicada nymphs produced during the insect’s 

mass emergence. (Jim Occi, BugPics, Bugwood.org)
A Photographic Guide 39

Images of the Periodical 

Cicada (continued)

Figure 7. Flagging of 

branches due to oviposition 

wounds of periodical cicada. 

(John H. Ghent, 

USDA Forest Service, 

Bugwood.org)

Figure 8. Close up of branch flagging from oviposition wounds of periodical 

cicada. (Jim Occi, BugPics, Bugwood.org)

Almost everything seems to eat periodical cicadas including birds, 

squirrels, snakes, spiders, etc. The massive populations of periodical 

cicadas, however, are able to satiate such predators and they appear to 

have little effect in reducing cicada densities.

Important Biological Control 

Agents Related to this 

Pest Species
40 Forest Pest Insects in North America:

http://insects.ummz.lsa.umich.edu/fauna/michigan_cicadas/periodical/

index.html; discusses the various species of periodical cicadas.

http://www.magicicada.org/about/species_pages/m_sdecim.php; has 

sound files of cicada songs.

Miller, F.D. 1997. Effects and control of periodical cicada Magicicada

septendecim and Magicicada cassini oviposition injury on urban forest 

trees. Journal of Arboriculture 23(6): 225-232. 

Miller, F. and W. Crowley. 1998. Effects of periodical cicada 

ovipositional injury on woody plants. Journal of Arboriculture 24(5): 

248-253.

Web Links for Information 

on the Periodical Cicada

Articles
A Photographic Guide 41

15. Eastern Spruce Gall Adelgid, Adelges abietis (L.) (Hemiptera: Adelgidae)

Eastern spruce gall adelgid, Adelges abietis (L.), is a pest of the 

introduced Norway spruce (Picea abies [L.]) and of various native 

North American spruces, especially white spruce (P. glauca [Moench]). 

It is an invasive species believed to be of European origin. Damage is 

caused by induction of galls on new growth. Adults, which are wingless, 

deposit their eggs near buds in spring and newly developing needles 

are stimulated by developing nymphs to become enlarged, fusing into 

a pineapple-shaped gall, within which nymphs mature. In summer 

and early fall, the chambers of the gall open and nymphs emerge and 

transform themselves into winged adults, which lay eggs. These hatch 

and nymphs overwinter at the base of needles and buds. In spring, when 

the gall is newly formed, it is light green in color, but after it matures and 

insects emerge, it dries and turns brown, remaining on the branch as a 

sign of earlier infestation. Damage results from twig deaths induced by 

galls, which makes the tree misshapen. Heavily infested trees may die. 

This adelgid feeds on black (P. mariana (Mill.) Britton, Sterns & 

Poggenburg), Norway (P. abies), and white (P. glauca) spruces.

Eastern spruce gall adelgid occurs widely in the eastern United States 

from Maine to Tennessee and Illinois, as well as in northern Minnesota, 

Wisconsin, and Michigan, and adjacent parts of Canada. Localized 

infestations also occur in parts of Montana, Wyoming, and South Dakota. 

A map of this distribution is available at http://www.fs.fed.us/nrs/tools/

afpe/maps/ESGA.pdf.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of Eastern

Spruce Gall Adelgid

Figure 1. Close view of living galls of eastern spruce gall adelgid, Adelges abietis. 

(E. Bradford Walker, Vermont Department of Forests, Parks and Recreation, 

Bugwood.org)
42 Forest Pest Insects in North America:

Images of Eastern Spruce 

Gall Adelgid (continued)

Figure 2. Living galls of 

eastern spruce gall adelgid 

cut in cross section and 

showing chambers where 

insects feed. (Thérèse 

Arcand - Natural Resources 

Canada, Canadian Forest 

Service) 

Figure 3. Dead galls of eastern spruce gall adelgid. (E. Bradford Walker, Vermont 

Department of Forests, Parks and Recreation, Bugwood.org)

Figure 4. Openings in gall of eastern spruce gall adelgid after insect emergence. 

(Stanislaw Kinelski, Bugwood.org)
A Photographic Guide 43

Figure 5. Adult of eastern 

spruce gall adelgid, 

Adelges abietis. (Thérèse 

Arcand - Natural Resources 

Canada, Canadian Forest 

Service)

Because damage from this species is not severe, natural enemies have 

not been imported from the pest’s native range into North America for 

control. Predacious flies have been observed feeding on this adelgid in 

Europe (the syphid Cnemodon sp.) and, in Turkey, Leucopis species have 

been recorded feeding on related adelgids, but in general little is known 

about the natural enemies of this species.

http://www.ravageursexotiques.gc.ca/ins_details_eng.asp?pestType=ins&

lang=en&geID=5306; website of Environment Canada on invasive forest 

insects.

http://ohioline.osu.edu/hyg-fact/2000/2550.html; fact sheet of Ohio State 

University, includes information on control.

Flaherty, L., D. Quiring, and J.A. Kershaw, Jr. 2010. Post-gall induction 

performance of Adelges abietis (L.) (Homoptera: Adelgidae) is 

influenced by clone, shoot length, and density of colonising gallicolae. 

Ecological Entomology 35: 9-15.

Images of Eastern Spruce 

Gall Adelgid (continued)

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information on

Eastern Spruce Gall Adelgid

Articles
44 Forest Pest Insects in North America:

16. Balsam Woolly Adelgid, Adelges piceae (Ratzeburg) (Hemiptera: 

Adelgidae)

Balsam woolly adelgid, Adelges piceae (Ratzeburg), attacks only true 

firs (Abies). It is native to Eurasia and is a serious invasive pest in 

both eastern and western North America. Balsam woolly adelgids are 

small, <1 mm in size, and covered with white, woolly wax. Adults 

and nymphs feed on both the bole and twigs and inject hormones with 

their saliva that causes gouty twigs and growth of compression wood 

on the bole. These deformities disrupt water conduction and reduce 

tree growth and market value. Heavy infestations eventually kill the 

tree. Extensive damage to Fraser fir (Abies fraseri [Pursh] Poir.) in the 

southern Appalachian Mountains caused severe ecological damage to 

unique mountain-top habitats created by stands of this species. Damage 

to balsam (A. balsamea (L.) Mill.) and western firs has caused significant 

economic losses due to a combination of elevated rates of tree mortality 

and reduced growth. Various predators imported and released during the 

1950s from the European Alps failed to bring the pest under biological 

control. However, it is possible that the Alps themselves were an invaded 

area and that the true native range is the Caucasus Mountains. Thus, this 

region has potential as a source of effective natural enemies for this pest. 

The host plants of balsam woolly adelgid are Fraser fir (A. fraseri), 

balsam fir (A. balsamea), subalpine fir (A. lasiocarpa [Hooker] Nuttall), 

Pacific silver fir (Abies amabilis Douglas ex J. Forbes), and grand fir 

(A. grandis [Douglas ex D. Don] Lindley).

Balasm woolly adelgid is found in New York, New England, the 

Canadian Maritimes, British Columbia, the Pacific northwestern U.S. 

states, and limited areas of the southern Appalachian Mountains and the 

central coast of California. 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Figure 1. Distribution of 

balsam woolly adelgid, 

Adelges piceae, in North 

America. (USDA Forest 

Service, Forest Insect 

& Disease Leaflet 118 

revised May 2006)
A Photographic Guide 45

Images of Balsam

Woolly Adelgid

Figure 2. Bole of fir tree infested with 

balsam woolly adelgid. (USDA Forest 

Service - Ashville Archive, USDA Forest 

Service, Bugwood.org)

Figure 3. Close view of balsam woolly 

adelgids on bark of fir tree. (Ladd 

Livingston, Idaho Department of Lands, 

Bugwood.org)

Figure 4. High magnification of crawler (first instar) of balsam woolly adelgid. 

(USDA Forest Service - Ashville Archive, USDA Forest Service, Bugwood.org)
46 Forest Pest Insects in North America:

Images of Balsam

Woolly Adelgid

Figure 6. Fraser fir trees killed by balsam woolly adelgid. (Robert L. Anderson, 

USDA Forest Service, Bugwood.org)

More than 23 species of natural enemies were imported and released 

into the United States against this pest. Six species established, but 

remain rare: Aphidecta obliterata (L.) (Coleop.: Coccinellidae), 

Scymnus impexus (Mulsant) (Coleop.: Coccinellidae), Laricobius 

erichsonii (Rosenhauer) (Coleop.: Derodontidae), Aphidoletes thompsoni

Möhn (Diptera: Cecidomyiidae), Cremifania nigrocellulata Czerny 

(Diptera: Chamaemyiidae), and Leucopis obscura (Hal.) (Diptera: 

Chamaemyiidae).

Important Biological Control 

Agents Related to this 

Pest Species

Figure 5. Goutiness of Fraser fir twigs due to feeding by balsam woolly adelgid. 

(William M. Ciesla, Forest Health Management International, Bugwood.org)
A Photographic Guide 47

http://www.na.fs.fed.us/pubs/fidls/bwa.pdf; U.S. Department of 

Agriculture, Forest Service Forest Insect & Disease Leaflet 118 (Revised 

May 2006). 

http://pubs.ext.vt.edu/3006/3006-1452/3006-1452.pdf; Virginia 

Cooperative Extension bulleting on balsam woolly adelgid by Scott 

Salom and Eric Day.

http://www.ces.ncsu.edu/fletcher/programs/xmas/ctnotes/ctn020.html; 

North Carolina State University Cooperative Extension (a short bulletin 

discussing how to manage this pest in Christmas trees).

Harris, J.W.E. and A.F. Dawson. 1979. Predator release program for 

balsam woolly aphid, Adelges piceae (Homoptera: Adelgidae), in British 

Columbia, 1960-1969. Journal of the Entomological Society of British 

Columbia 76: 21-26. 

Schooley, H.O. and L. Oldford. 1981. An annotated bibliography of the 

balsam woolly aphid (Adelges piceae [Ratzeburg]). Information Report 

N-X-196, Canadian Forestry Service: 97 p.

Schooley, H.O., J.W.E. Harris, and B. Pendrel. 1984. Adelges piceae

(Ratz.) balsam woolly adelgid (Homoptera: Adelgidae). In: Kelleher, J.S. 

and M.A. Hulme (eds.). Biological Control Programmes against Insects 

and Weeds in Canada, 1969-1980. Commonwealth Agricultural Bureaux, 

Farnham Royal, England: 229-234. 

McManamay, R.H., L.M. Resler, J.B. Campbell, and R.A. McManamay. 

2011. Assessing the impacts of balsam woolly adelgid (Adelges piceae

Ratz.) and anthropogenic disturbance on the stand structure and mortality 

of Fraser fir [Abies fraseri (Pursh) Poir.] in the Black Mountains, North 

Carolina. Castanea 76(1): 1-19.

Web Links for Information 

on Balsam Woolly Adelgid

Articles
48 Forest Pest Insects in North America:

17. Hemlock Woolly Adelgid, Adelges tsugae Annand (Hemiptera: 

Adelgidae)

Hemlock woolly adelgid, Adelges tsugae Annand, is an invasive insect 

in eastern North America. DNA evidence suggests that the invasive 

eastern U.S. population came from Japan and not the western United 

States, where the species is also present. Hemlock woolly adelgids are 

small in size and to the naked eye only their woolly coverings are easily 

visible. The insect has two generations per year and growth occurs from 

fall through late spring. Insects in summer are inactive and scarcely 

visible at the bases of needles as black dots. Woolly masses (the sign 

allowing the species to be recognized) develop in October and are 

present thereafter through June of the following year. In the western 

United States, A. tsugae feeds on western hemlock (Tsuga heterophylla

[Raf.] Sarg.) but is believed to be native and is not a pest. In the eastern 

USA, hemlock woolly adelgid is killing eastern (T. canadensis [L.] 

Carrière) and Carolina (T. caroliniana Engelm.) hemlocks in large 

numbers from Connecticut south along the Appalachian Mountains. 

From Massachusetts north, or at high elevations, tree mortality has been 

restrained by higher rates of mortality of adelgids in winter due to low 

temperatures. A biological control program is in progress against this 

pest, based on specialized predatory beetles that feed only on adelgids, 

collected in western North America (Laricobius nigrinus Fender) or 

China/Japan (species of Laricobius and various Scymnus ladybird 

beetles). To date, releases have not demonstrated any reductions in 

adelgid densities from predators. Populations of L. nigrinus have become 

well established and abundant in some areas of western North Carolina. 

In North America, this species feed only on eastern hemlock 

(T. canadensis), Carolina hemlock (T. caroliniana), and western hemlock 

(T. heterophylla).

The hemlock woolly adelgid is found as a native species in the western 

United States in the Pacific northwestern states (Oregon, Washington, 

Idaho, and Montana) and as an invasive species from Japan in the eastern 

United States, from southern Maine to northern Georgia. 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Figure 1. Distribution of hemlock 

woolly adelgid, Adelges tsugae, 

in the eastern United States in 2009. 

(USDA Forest Service, Northeastern 

Area, Forest Health Protection - 

Distribution Maps)
A Photographic Guide 49

Images of 

Hemlock Woolly Adelgid

Figure 2. Hemlock woolly adelgid on hemlock. (Michael Montgomery, USDA 

Forest Service, Bugwood.org)

Figure 3. Individuals of hemlock woolly adelgid covered with white wool (see 

crawler emerging, arrow). (Pennsylvania Department of Conservation and 

Natural Resources - Forestry Archive, Bugwood.org)

Figure 4. High 

magnification of the 

aphid-like body of an adult 

hemlock woolly adelgid 

after removal of the wool. 

(Michael Montgomery, 

USDA Forest Service, 

Bugwood.org)
50 Forest Pest Insects in North America:

Images of Hemlock 

Woolly Adelgid (continued)

Figure 5. Eggs of hemlock woolly adelgid (wool pulled aside for viewing). 

(Lorraine Graney, Bartlett Tree Experts, Bugwood.org)

Figure 6. Damage from hemlock woolly adelgid is seen as needle loss, leading to 

branch death. (Chris Evans, River to River CWMA, Bugwood.org)

Figure 7. Dead or dying hemlock in 

Joyce Kilmer area, North Carolina due 

to hemlock woolly adelgid feeding. 

(Jason VanDriesche, Bugwood.org)
A Photographic Guide 51

Images of Hemlock 

Woolly Adelgid (continued)

Figure 8. Laricobius nigrinus, which feeds only on adelgids, is the most promising 

agent released so far against hemlock woolly adelgid. (Ashley Lamb, Virginia 

Polytechnic Institute and State University, Bugwood.org)

There is an on going classical biological control project against this 

pest. As of 2010, the principal species introduced against this pest have 

been the following four species: Sasajiscymnus tsugae (Sasaji and 

McClure) (Coleop.: Coccinellidae), Scymnus sinuanodulus Yu and Yao 

(Coleop.: Coccinellidae), Scymnus ningshanensis Yu and Yao (Coleop.: 

Coccinellidae), and Laricobius nigrinus Fender (Coleop.: Derodontidae).

http://na.fs.fed.us/fhp/hwa/biology/biological_control.shtm; information 

on hemlock woolly adelgid’s biology, impacts, distribution, and control 

(chemical and biological).

http://www.na.fs.fed.us/spfo/pubs/pest_al/hemlock/hwa05.htm; a brief 

printable summary of life history and control;

http://www.dcnr.state.pa.us/forestry/woollyadelgid/index.aspx; contains 

an annual life cycle diagram.

Zilahi-Balogh, G.M.G., L.T. Kok, and S.M. Salom. 2002. Host 

specificity of Laricobius nigrinus Fender (Coleoptera: Derodontidae), a 

potential biological control agent of the hemlock woolly adelgid, Adelges

tsugae Annand (Homoptera: Adelgidae). Biological Control 24: 192-198.

Zilahi-Balogh, G.M.G., S.M. Salom, and L.T. Kok. 2003. Development 

and reproductive biology of Laricobius nigrinus, a potential biological 

control agent of Adelges tsugae. BioControl 48: 293-306.

Mausel, D.L., S.M. Salom, L.T. Kok, and G.A. Davis. 2010. 

Establishment of the hemlock woolly adelgid predator, Laricobius

nigrinus (Coleoptera: Derodontidae), in the eastern United States. 

Environmental Entomology 39: 440-448.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Hemlock Woolly Adelgid

Articles
52 Forest Pest Insects in North America:

Articles on 

Hemlock Woolly Adelgid 

(continued)

Krapfl, K.J., E.J. Holzmueller, and M.A. Jenkins. 2011. Early impacts of 

hemlock woolly adelgid in Tsuga canadensis forest communities of the 

southern Appalachian Mountains. Journal of the Torrey Botanical Society

138: 93-106.

Montgomery, M.E., S. Shiyake, N.P. Havill, and R.A.B. Leschen, 2011. 

A new species of Laricobius (Coleoptera: Derodontidae) from Japan 

with phylogeny and a key for native and introduced congeners in North 

America. Annals of the Entomological Society of America 104: 389-401.
A Photographic Guide 53

18. Cooley Spruce Gall Adelgid, Adelges cooleyi (Gillette) (Hemiptera: 

Adelgidae)

Cooley spruce gall adelgid, Adelges cooleyi (Gillette), is native to 

the Rocky Mountain region of North America, where it galls various 

species of spruce (Picea). It is also found in Europe, where it was 

accidentally introduced through movement of North American conifers 

for use in plantations, and where it is a pest in plantations of Douglas-fir 

(Pseudotsuga menziesii [Mirbel] Franco). In North America, damage 

occurs principally on landscape trees and in plantations. Damage is 

not important in native forests. Galls are formed on the apical portion 

of shoot, in contrast to eastern spruce gall adelgid (Adelges abietis

[L.]) galls that are found on the basal portion of the twig. Damage is 

merely aesthetic, but may be economically significant in Christmas tree 

plantations.

The most important host is blue spruce (Picea pungens Engelm.), 

but other species attacked include white spruce (P. glauca [Moench] 

Voss), Sitka spruce (P. sitchensis [Bong.] Carr.), Engelmann spruce 

(P. engelmannii Parry ex Engelm.), and as an alternate host, Douglas-fir 

(P. menziesii)

This species occurs from coast to coast in the northern United States and 

throughout the range of white spruce in Canada. Populations occur in the 

eastern United States where blue spruce is planted as an ornamental.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of Cooley Spruce 

Gall Adelgid

Figure 1. Appearance of the large (2-3 cm long) galls caused by Cooley spruce 

gall adelgid, Adelges cooleyi. (Whitney Cranshaw, Colorado State University, 

Bugwood.org)
54 Forest Pest Insects in North America:

Images of Cooley Spruce 

Gall Adelgid (continued)

Figure 2. Close view of living galls of Cooley spruce gall adelgid. (Whitney 

Cranshaw, Colorado State University, Bugwood.org)

Figure 3. Living galls of Cooley spruce gall adelgid cut in cross section and 

showing chambers where insects feed. (Chris Schnepf, University of Idaho, 

Bugwood.org)

Figure 4. Overwintering adults of Cooley spruce gall adelgid. (Whitney Cranshaw, 

Colorado State University, Bugwood.org)
A Photographic Guide 55

Images of Cooley Spruce 

Gall Adelgid (continued)

Figure 5. Appearance of Cooley spruce 

gall adelgids on its alternate host, 

Douglas-fir. (Ladd Livingston, Idaho 

Department of Lands, Bugwood.org)

Figure 6. Heavy infestation of Cooley 

spruce gall adelgid on Christmas trees. 

Such trees are not saleable. (Eric R. 

Day, Virginia Polytechnic Institute and 

State University, Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

Little to nothing is known of the natural enemies of this species. 

Investigations in its native range in the Rocky Mountains of North 

America may be useful as a source of natural enemies for importation to 

Europe, where this species is an invasive pest.

http://imfc.cfl.scf.rncan.gc.ca/insecte-insect-eng.asp?geID=5307; website 

of Environment Canada on invasive forest insects.

http://ohioline.osu.edu/hyg-fact/2000/2551.html; fact sheet of Ohio State 

University that includes information on control.

Lasota, J.A. and D.J. Shetlar. 1986. Assessing seasonal and spatial 

abundance of Adelges cooleyi (Gillette) (Homoptera: Adelgidae) by 

various sampling techniques. Environmental Entomology 15: 254-257.

Cranshaw, W.S. 1989. Patterns of gall formation by the Cooley spruce 

gall adelgid on Colorado blue spruce. Journal of Arboriculture 15(11): 

277-280.

Web Links for Information on 

Cooley Spruce Gall Adelgid

Articles
56 Forest Pest Insects in North America:

19. Pine Bark Adelgid, Pineus strobi (Hartig) (Hemiptera: Adelgidae)

Orientation to Pest Pine bark adelgid, Pineus strobi (Hartig), populations are at times 

dense and strikingly visible; however, this native adelgid is generally 

only a minor pest of eastern white pine (Pinus strobus L.). Even dense 

populations do little harm if the tree is otherwise healthy. In plantations 

and on Christmas trees, pine bark adelgid infestations may reduce growth 

and induce excessive branching, reducing the value of Christmas trees. 

The species may have up to five generations per year. 

The host of this species is eastern white pine (P. strobus).

This adelgid is found widely in North America throughout the range of 

eastern white pine.

Hosts Commonly Attacked

Distribution

Images of 

Pine Bark Adelgid

Figure 1. An infestation of pine bark 

adelgid, Pineus strobi, on the trunk 

of eastern white pine. (Petr Kapitola, 

State Phytosanitary Administration, 

Bugwood.org)

Figure 2. Closer view of pine trunk 

infested with pine bark adelgid. 

(Steven Katovich, USDA Forest 

Service, Bugwood.org)
A Photographic Guide 57

Images of Pine Bark 

Adelgid (continued)

Figure 3. Pine bark adelgids infesting pine branch. (Petr Kapitola, State 

Phytosanitary Administration, Bugwood.org)

Figure 5. Laricobius rubidus

(Coleop.: Derodontidae) is an 

important predator of pine bark 

adelgid in the eastern United States. 

(Jim McClarin, BugGuide.net)

Figure 4.Excess bud formation from pine bark adelgid feeding can cause shoot 

proliferation in tree top. Note also the lady beetle feeding on the adelgids. (Eric 

R. Day, Virginia Polytechnic Institute and State University, Bugwood.org)
58 Forest Pest Insects in North America:

Because damage from this species is generally not important in North 

America, natural enemies of this species have not been well studied. 

However, some predators of this adelgid, have been noted in the eastern 

United States, including the derodontid beetle Laricobius rubidus

LeConte and chamaemyiid fly Leucopis pinicola Mall. 

http://pubs.ext.vt.edu/2907/2907-1402/2907-1402.pdf; Virginia Tech 

extension leaflet updated by Scott Salom.

Sluss, T.P. and B.A. Foote. 1973. Biology and immature stages 

of Leucopis pinicola and Chamaemyia polystigma (Diptera: 

Chamaemyiidae). The Canadian Entomologist 105: 1443-1452.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Pine Bark Adelgid

Articles
A Photographic Guide 59

20. Pine Leaf Adelgid, Pineus pinifoliae (Fitch) (Hemiptera Adelgidae)

Pine leaf adelgid, Pineus pinifoliae (Fitch), is native to North America 

and feeds alternatively on spruce (Picea) and pine (Pinus). On spruce, 

galls are produced. On pine, nymphs feeds openly on terminal foliage. 

In the eastern United States, red (Picea rubens Sargent) and black (P.

mariana [Miller] Britton, Sterns and Poggenburg) spruce are the initial 

hosts, with adults produced there, migrating to white pine (Pinus strobus

L.). In the western United States, the initial hosts are Engelmann spruce 

(Picea engelmannii Parry ex Engelm.), black spruce, blue spruce (P.

pungens Engelm.), and white spruce (P. glauca [Moench] Voss), and the 

pine host is western white pine (Pinus monticola Douglas ex D. Don). 

Two years are required to complete this cycle among tree hosts. Pine leaf 

adelgid can be an important pest in white pine plantations on young trees. 

Heavy infestations can reduce growth of pine or even kill trees. Galls on 

spruce do not damage the health of the tree.

This species feeds on red (Picea rubens), black (P. mariana), Engelmann 

(P. engelmannii), blue (P. pungens), and white (P. glauca) spruce as 

primary hosts and eastern white (Pinus strobus) and western white 

(P. monticola) pines as alternate hosts.

This adelgid is found widely in North America wherever the ranges of its 

primary and alternative hosts overlap.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of 

Pine Leaf Adelgid

Figure 1. Close view of pine leaf adelgid, Pineus pinifoliae, on a spruce host. 

(Whitney Cranshaw, Colorado State University, Bugwood.org)
60 Forest Pest Insects in North America:

Images of Pine Leaf 

Adelgid (continued)

Figure 2. Fresh gall of pine leaf adelgid on a spruce host. (Whitney Cranshaw, 

Colorado State University, Bugwood.org)

Figure 3. Old gall of pine leaf adelgid on a spruce host, after adelgid emergence. 

(Whitney Cranshaw, Colorado State University, Bugwood.org)

Figure 4. Adults of pine leaf adelgid on a pine host. (E. Bradford Walker, Vermont 

Department of Forests, Parks and Recreation, Bugwood.org)
A Photographic Guide 61

Figure 5. Flagging tip on pine, a symptom of feeding of pine leaf adelgid. 

(Ronald S. Kelley, Vermont Department of Forests, Parks and Recreation, 

Bugwood.org)

Images of Pine Leaf 

Adelgid (continued)

No information is available on the natural enemies of this adelgid. They 

are likely to be similar to those recorded for other Pineus and Adelges

species in North America.

http://www.forestpests.org/vermont/pineleafadelgid.html; fact sheet of 

the state of Vermont of biology and control. 

http://www.maine.gov/doc/mfs/pineleaf.htm; fact sheet of the state of 

Maine on biology and control.

Dimond, J.B. 1974. Sequential surveys for the pine leaf chermid, Pineus 

pinifoliae. Technical Bulletin No. 68, Life Sciences and Agriculture 

Experiment Station, University of Maine; Orono, Maine, USA: 15 p.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Pine Leaf Adelgid

Articles
62 Forest Pest Insects in North America:

21. White Pine Aphid, Cinara strobi (Fitch) (Hemiptera: Aphidae)

White pine aphid, Cinara strobi (Fitch), is a native insect in North 

America that feeds on white pine (Pinus strobus L.). It is easily 

recognized by its large size (3-4 mm), slightly dull metallic grey color 

with a white stripe on middle of the thorax and spots of white wax on 

each side of the abdomen. Eggs are laid in the fall, end-to-end along the 

needle and hatch in the spring. White pine aphid feeds on branches and 

upper trunks. Because it forms large colonies and is large, it produces 

copious amounts of honeydew. It is usually attended by ants. Other than 

the honeydew being a nuisance and fostering sooty mold, direct damage 

to the tree itself is rare; but occasionally dense aphid populations damage 

young pines or individual branches of large trees.

This aphid is only found on white pine (P. strobus).

White pine aphid is found in the United States from New England to 

the Great Lakes states, south to the Carolinas in association with eastern 

white pine.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of 

White Pine Aphid

Figure 1. Close view of white pine aphid, Cinara strobi. (Jim Baker, North 

Carolina State University, Bugwood.org)
A Photographic Guide 63

Images of White Pine 

Aphid (continued)

Figure 2. Colony of white 

pine aphid. (William H. 

Hoffard, USDA Forest 

Service, Bugwood.org)

Figure 3. Eggs of white pine aphid on pine needle. (Lacy L. Hyche, Auburn 

University, Bugwood.org)

The braconids Pauesia bicolor (Ashmead) and Pausia xanthothera

(Smith) are known as parasitoids of this and other aphids in the genus 

Cinara.

http://wiki.bugwood.org/Cinara_strobi

None

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on White Pine Aphid

Articles
64 Forest Pest Insects in North America:

22. Woolly Elm Aphid, Eriosoma americanum (Riley) (Hemiptera: Aphididae; 

Eriosomatinae)

Woolly elm aphid, Eriosoma americanum (Riley), is a native insect 

in North America whose primary hosts are American elm (Ulmus 

americana L.) and secondary, summer hosts are serviceberry (called 

saskatoon in Canada) and other species of Amelanchier spp. This aphid 

flies to elm in the fall where it mates and lays overwintering eggs. These 

hatch in the spring and nymphs feed on the edges of young elm leaves, 

causing them to roll inward and form a gall over the colony. In early 

summer, winged-forms migrate to Almelanchier species where they form 

colonies on the roots. Two other species of Eriosoma may also be found 

on elm, E. lanigerum (Hausmann) that causing terminal shoots to form 

rosettes and E. rileri Thomas, which forms woolly clusters on limbs and 

trunks. This aphid is a minor pest on Amelanchier alnifolia (Nutt.), which 

is a fruit crop in Manitoba, Canada.

American elm (U. americana) is the primary host, and species of 

serviceberry (Amelanchier) are the alternative hosts.

Woolly elm aphid is widely distributed throughout the eastern United 

States and Canada in the range of elm and serviceberry species.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of Woolly 

Elm Aphid

Figure 1. Winged adult 

of woolly elm aphid, 

Eriosoma americanum. 

(Government of 

Alberta, Agriculture and 

Rural Development, 

agriculture.alberta.ca)

Figure 2. Elm leaf galled by woolly elm aphid. (Steven Katovich, USDA Forest 

Service, Bugwood.org)
A Photographic Guide 65

Figure 3. Stem of 

serviceberry infested by 

woolly elm aphid. (Whitney 

Cranshaw, Colorado State 

University, Bugwood.org) 

Images of Woolly 

Elm Aphid (continued)

Given this aphid’s native status and limited damage, little is known 

about its natural enemies. In North America, some predators have been 

observed feeding on it, including the mirid Saileria irrorata Henry and 

the coccinellid Scymnus brulleri Mulsant.

http://www.gov.mb.ca/agriculture/crops/insects/fad92s00.html; gives 

details of biology and effect on saskatoon (A. alnifolia),which is grown 

for its fruit in Manitoba, Canada.

http://wiki.bugwood.org/Eriosoma_americanum; entry in Bugwood Wiki.

Miranpuri, G.S. and G.G. Khachatourians. 1996. Bionomics and 

fungal control of woolly elm aphid, Eriosoma americanum (Riley) 

(Eriosomatidae: Homoptera) on Saskatoon berry, Amelanchier alinifolia. 

Journal of Insect Science 9: 33-37.

Fry, K.M. 2001. Eriosoma americanum (Riley), woolly elm aphid 

(Homoptera: Pemphigidae). Mason, P.G. and J.T. Huber (eds.). 

Biological Control Programmes in Canada, 1981-2000. CABI 

Publishing, Wallingford, UK: 120-123.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Woolly Elm Aphid

Articles
66 Forest Pest Insects in North America:

23. Woolly Beech Aphid, Phyllaphis fagi (L.) (Hemiptera: Aphidae)

Woolly beech aphid, Phyllaphis fagi (L.), is an invasive aphid in North 

America, likely of European origin. It feeds on all species of beech, 

but high densities are usually only found on European beech (Fagus 

sylvatica L.), which is widely used in landscape plantings. The aphid 

is usually not a problem in the United States on the American beech, 

F. grandifolia Ehrh., growing in forests or low stress sites. This woolly 

aphid, which feeds on the undersides of leaves, can be confused with 

the beech blight aphid (Grylloprociphilus imbricator [Fitch]), which 

begins feeding on the leaves and then moves onto stems. The woolly 

beech aphid eggs hatch in the spring and there are about ten generations 

per year of apterous and winged forms, which occur together. Huge 

populations can occur year after year without causing visible harm to the 

tree. The massive amounts of honeydew produced by large colonies can 

be a nuisance. 

This aphid is found most often on European beech (F. sylvatica L.) 

planted in urban or residential landscapes.

This aphid is widely distributed in both eastern and western North 

America, where ever beech is grown. 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of Woolly

Beech Aphid

Figure 1. Colony of woolly beech aphid, Phyllaphis fagi, on undersurface of 

leaves of European beech. (Haruta Ovidiu, University of Oradea, Bugwood.org)
A Photographic Guide 67

Figure 3. Leaf rolling on European beech, a symptom of damage by woolly 

beech aphid. (Louis-Michel Nageleisen, Département de la Santé des Forêts, 

Bugwood.org)

Figure 2. Close up of woolly beech aphid showing nymphs and older stages 

with wool. (Louis-Michel Nageleisen, Département de la Santé des Forêts, 

Bugwood.org)

Images of Woolly

Beech Aphid (continued)

The braconid parasitoids Praon flavinode (Haliday) and Trioxys

phyllaphidis Mackauer are known to attack this species in Europe, but 

are not reported from North America. 

http://www.plante-doktor.dk/boegebladluseng.htm; Danish fact sheet on 

control of this species. 

Iversen, T. and S. Harding. 2007. Biological and other alternative control 

methods against the woolly beech aphid, Phyllaphis fagi L., on beech, 

Fagus sylvatica, seedlings in forest nurseries. Journal of Pest Science 80: 

159-166. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Woolly Beech Aphid

Articles
68 Forest Pest Insects in North America:

24. Tuliptree Aphid, Illinoia liriodendri (Monell) (Hemiptera: Aphididae)

Tuliptree aphid, Illinoia liriodendri (Monell), is a relatively large aphid 

(1.7-2.0 mm), spindle-shaped, pale green and lightly dusted with wax, 

that is native to the eastern United States. It occurs east of the Mississippi 

River, except northern New England, wherever its hosts, the tuliptree 

(Liriodendron tulipifera L.) and some species of magnolia (Magnolia), 

are endemic. It is also invasive in many areas where tuliptrees have been 

planted as ornamentals outside their native range, including California 

and other parts of the western USA, Europe (France, Germany, Italy, 

Slovenia, UK), Japan, and Canada (Ontario, British Columbia). This 

aphid is of little or no concern in its native range, but in parts of its 

invaded range, high aphid densities occur that produce unsightly coatings 

of honeydew and sooty mold. 

This aphid’s hosts are the tuliptree (L. tulipifera L.) and some species of 

magnolia (Magnolia).

Tuliptree aphid is found throughout the eastern USA and in urban areas 

of California and other western states where tuliptrees have been planted. 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Image of 

Tuliptree Aphid

Figure 1. Adult and nymphs of tuliptree aphid, Illinoia liriodendra. 

(Robert L. Anderson, USDA Forest Service, Bugwood.org)
A Photographic Guide 69

Parasitoids of this aphid in its native range (the eastern United States) 

include a species of Praon, Ephedrus incompletus Provancher, Aphidius

polygonaphis (Fitch), A. nigripes Ashmead, and A. rosae Haliday. Three 

parasitoids—a Praon species, E. incompletus, and A. polygonaphis—

were imported from the eastern United Statees and released in California, 

where A. polgonaphis established but did not completely control the 

aphid population. 

http://meta.arsia.toscana.it/meta/meta?id_cms_doc=1&id_news=201; an 

Italian site covering this species as a pest of ornamentals.

Zuparko, R.L. and D.L. Dahlsten. 1993. Survey of the parasitoids of 

the tuliptree aphid, Illinoia liriodendri (Hom: Aphididae), in northern 

California. Entomophaga 38: 31-40.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Tuliptree Aphid

Articles
70 Forest Pest Insects in North America:

25. Norway Maple Aphid, Periphyllus lyropictus (Kessler) (Hemiptera: 

Aphidae)

Norway maple aphid, Periphyllus lyropictus (Kessler), is a European 

species that is invasive in the United States, where it occurs on Norway 

maple (Acer platanoides L.). This aphid is widespread in eastern North 

America, wherever Norway maple is planted. Given that Norway maple 

is now considered an invasive forest pest in many areas, this aphid’s 

damage to the tree might be considered beneficial. Large populations 

can cause leaves to become brown or wrinkled and cause premature 

leaf drop. However, the primary concern is usually the large amount 

of honeydew it can produce, which is a nuisance to sidewalks and cars 

beneath the trees. Both winged and wingless forms occur and the latter 

form has a yellow-green body with a “lyre”-shaped brownish marking on 

the abdomen. 

Its only host in North America is the imported species Norway maple 

(A. platanoides).

This aphid is found widely in eastern North America, wherever Norway 

maple has been planted.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of 

Norway Maple Aphid

Figure 1. Colony of Norway maple aphid, Periphyllus lyropictus. 

(Michael Montgomery, USDA Forest Service, Bugwood.org)
A Photographic Guide 71

Figure 2. Sooty mold and cast skins of Norway maple aphid. (Pennsylvania 

Department of Conservation and Natural Resources - Forestry Archive, 

Bugwood.org)

Images of Norway 

Maple Aphid (continued)

In its native range in Europe, three species of parasitoids have been 

recorded that are believed to be specialized on this genus of aphid: 

Aphidius setiger Mackauer, Trioxys falcatus Mackauer, and Praon

silvestre Starý. Of these, only A. setiger is known to be present in North 

America.

None

Starý, P. 1972. Host life-cycle and adaptation of parasites of Periphyllus 

aphids (Homoptera, Chaitophoridae; Hymenoptera, Aphidiidae). Acta 

Entomologica Bohemoslovaca 69(2): 89-96.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Norway Maple Aphid

Articles
72 Forest Pest Insects in North America:

26. Linden Aphid, Eucallipterus tiliae (L.) (Hemiptera: Aphididae)

Linden aphid, Eucallipterus tiliae (L.), is invasive in the United States. 

It is native to Eurasia, but now occurs worldwide, wherever species of 

native or introduced linden trees (Tilia) occur. The winged adults are 

easily recognized by the black stripe along the body and the cloudyblack at the wing edge. Trees planted along streets and by parking areas 

are frequently attacked, and the honeydew produced by the aphid makes 

walkways and cars parked beneath them sticky. Sooty mold growing 

on honeydew blackens the leaves. Progeny are produced continuously 

during the growing season. It is attacked by several genera of parasitoids 

as well as lady beetles and other generalist predators. 

Basswood, also called American linden, (Tilia americana L.) and its 

variety, white basswood (T. americana var. heterophylla) are North 

American trees that are fed on by this aphid. However, damage to these 

plants is rarely serious because they are less susceptible to this aphid 

than are the introduced species of Tilia commonly planted in urban 

landscapes. Damage to such introduced species is the main focus of 

concern with this aphid.

This aphid is found widely in eastern North America on basswood and on 

exotic species of Tilia in landscape plantings. California, especially, has 

problems with this aphid on exotic Tilia and has introduced parasitoids 

for its biological control.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of Linden Aphid Figure 1. Winged adult linden 

aphid, Eucallipterus tiliae. 

(Bob Gaia)
A Photographic Guide 73

Figure 2. Nymph of linden 

aphid. (Bob Gaia)

Figure 3. Group of winged adult linden aphids on underside of Tilia leaf. 

(Whitney Cranshaw, Colorado State University, Bugwood.org)

Figure 4. Honeydew and sooty mold on linden, typical signs of linden aphid. 

(Whitney Cranshaw, Colorado State University, Bugwood.org)

Images of Linden Aphid

(continued)
74 Forest Pest Insects in North America:

Images of Linden Aphid

(continued)

Figure 5. Dark discoloration 

on cement caused by sooty 

mold growing on honeydew 

dripping from linden tree 

infested by linden aphid. 

(Whitney Cranshaw, 

Colorado State University, 

Bugwood.org)

In California, where this is an invasive aphid on exotic street trees, a 

species of European parasitoid, Trioxys curvicaudus Mackauer, was 

introduced and anecdotal information suggests this introduction lowered 

density of aphids on street lindens. In Europe, parasitoids seem not 

to be the primary regulator of linden aphid numbers, and generalist 

predators and density-dependent feedback from the tree are believed 

to be important. This aphid and seven related species occur in northern 

China and the Russian Far East; hence, this area may be a good source 

of natural enemies. There are ten parasitoid species in the superfamily 

Ichneumonoidea and nine in the Chalcidoidea recorded from aphids in 

the genus Eucallipterus. 

None found that provide significant information.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Linden Aphid
A Photographic Guide 75

Dixon, A.F.G. and N.D. Barlow. 1979. Population regulation in the lime 

aphid. Zoological Journal of the Linnean Society 67: 255-237.

Zuparko, R. 1983. Biological control of Eucallipterus tiliae [Hom.: 

Aphididae] in San Jose, California, through establishment of Trioxys

curvicaudus [Hym.: Aphidiidae]. Entomophaga 28: 325-330.

Hajek, A.E. 1986. New North American records of European parasitoids 

(Hymenoptera) of the linden aphid, Eucallipterus tiliae (Aphidoidea: 

Drepanosiphidae). Journal of the New York Entomological Society 94: 

443-446.

Blackman, R.L. and V.F. Eastop. 1994. Aphids on the World’s Trees: An 

Identification and Information Guide. CAB International, Oxfordshire, 

United Kingdom.

Zuparko, R.L. and D.L. Dahlsten. 1996. New potential for classical 

biological control of Eucallipterus tiliae (Homoptera: Drepanosiphidae. 

Biological Control 6: 407-408.

Foottit, R.G., S.E. Halbert, G.L. Miller, E. Maw, and L.M. Russell. 2006. 

Adventive aphids (Hemiptera: Aphididae) of America North of Mexico. 

Proceedings of the Entomological Society of Washington 108(3): 583-610.

Articles
76 Forest Pest Insects in North America:

27. Spruce Aphid, Elatobium abietinum (Walker) (Hemiptera: Aphidae)

Spruce aphid, Elatobium abietinum (Walker) (known as “green spruce 

aphid” in some places), is native to part of Europe, where it feeds on 

Norway spruce (Picea abies [L.] H. Karst). It is seldom a pest on this 

species in Europe, causing only infrequent, very minor local outbreaks. 

However, it is a major pest in northwestern Europe in plantations of 

North American Sitka spruce (P. sitchensis [Bong.] Carr. Outside of 

Europe, spruce aphid is invasive in many areas with maritime climates 

and also the montane forests of the southwestern United States. In 

North America, spruce aphid occurs in natural forests on various spruce 

species, mostly in coastal areas of the Pacific northwestern United States 

and British Columbia. It also occurs in Arizona, where spruce aphid 

outbreaks damage Engelmann spruce (P. engelmannii Parry ex Engelm.), 

killing 10 to 24 percent of infested trees, depending on the severity 

of injury. In maritime areas, spruce aphid is parthenogenic (females 

only), but in its native range and in Arizona the life cycle includes both 

parthenogenic and sexual forms. 

Spruce aphid feeds on virtually all spruce, including Norway (P. abies), 

Sitka (P. sitchensis), Englemann (P. engelmannii), and Colorado blue 

spruce (P. pungens Englmann).

In addition, to its native range in Europe, this aphid has invaded parts of 

Russia, Australia, New Zealand, Chile, and North America. It is found in 

British Columbia, Ontario, Quebec, California, North Carolina, Oregon, 

Arizona, Utah, and Washington.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Figure 1. Spruce aphid, Elatobium abietinum. (Donald Owen, California 

Department of Forestry and Fire Protection, Bugwood.org)

Images of Spruce Aphid
A Photographic Guide 77

Figure 2. Damage to Sitka spruce from spruce aphid. (Elizabeth Willhite, USDA 

Forest Service, Bugwood.org)

Figure 3. Stand of Sitka spruce in Alaska showing damage of spruce aphid 

(areas in brown). (Andris Eglitis, USDA Forest Service, Bugwood.org)

Images of Spruce Aphid

(continued)

Generalist predators of this species have been noted, but parasitoids 

have not been studied. Pathenogenic fungi, especially species of 

Entomophthorales, are important natural enemies of spruce aphid.

http://www.fs.fed.us/r3/resources/health/field-guide/sap/spruce.shtml

http://apps.rhs.org.uk/advicesearch/Profile.aspx?pid=520; a control 

factsheet from the UK Royal Horticultural Society. 

http://www.oregon.gov/ODF/privateforests/docs/fh/SpruceAphid.

pdf?ga=t

www.science.ulster.ac.uk/lnsrg/elatobium_abietinum.html; University 

of Ulster, Northern Ireland. Includes photos of some natural enemies of 

spruce aphid.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Spruce Aphid
78 Forest Pest Insects in North America:

Straw, N.A., J.E.L. Timms, and S.R. Leather. 2009. Variation in the 

abundance of invertebrate predators of the green spruce aphid Elatobium

abietinum (Walker) (Homoptera: Aphididae) along an altitudinal transect 

Elatobium abietinum. Forest Ecology and Management 258: 1-10.

Lynch, A.M. 2004. Fate and characteristics of Picea damaged by 

Elatobium abietinum (Walker) (Homoptera: Aphididae) in the White 

Mountains of Arizona. Western North American Naturalist 64: 7-17. 

Articles on Spruce Aphid
A Photographic Guide 79

28. Beech Scale, Cryptococcus fagisuga Lindinger (Hemiptera: 

Eriococcidae)

Beech scale, Cryptococcus fagisuga Lindinger, is invasive in the 

United States and very likely also invasive in Europe. Its native range is 

believed, based on studies of mitochondrial DNA, to be in western Asia 

(Turkey and the Caucasus Mountains) or southeastern Europe, where 

its host is oriental beech (Fagus orientalis Lipsky). It is a moderately 

damaging pest in Europe on European beech (F. sylvatica L.) and a 

devastating pest in North America of American beech (F. grandifolia

Ehrh.). The insect infests the trunk of beech, inducing cracking which 

allows invasion by fungal pathogens (genus Neonectria), which kill the 

trunk. Roots survive and trees regenerate, but the disease cycle is too 

frequent to permit most trees to reach large size. Trunks are deformed 

by cracking and the development of cankers. Visible signs are the white 

woolly coverings of scales and the red fruiting bodies of the Neonectria

fungus. About 1 percent of American beech are naturally immune from 

attack and remain healthy. Following the accidental introduction of the 

scale to the Halifax Arboretum in the late 1800s, an epidemic of beech 

bark disease has spread south and west, and now covers a substantial 

part of the range of American beech. This insect is apparently completely 

parthenogenetic; no males have ever been found.

Oriental beech (F. orientalis) is believed to be the native host. European 

beech (F. sylvatica) and American beech (F. grandifolia) are hosts 

acquired in invaded areas.

In North America, beech scale occurs from Nova Scotia to central 

Pennsylvania, with infested pockets in West Virginia, North Carolina, 

and Michigan, but continues to spread. In Eurasia, the scale is found 

from the United Kingdom to Iran. It is found throughout Europe; 

however, this area is no longer believed to be the native range. Of 

areas studied so far, mitochondrial haplotype diversity is greatest in the 

Caucasus Mountains and that area may be part of the original range of 

this insect. Surveys are underway in the Caucasus Mountains of Georgia 

for parasitoids of this scale. 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Figure 1. Distribution of beech 

scale, Cryptococcus fagisuga, and 

its associated invasive pathogen 

in North America in 2005, following 

its introduction in about 1890 in 

Halifax, Nova Scotia. (USDA Forest 

Service, Northeastern Area, Forest 

Health Protection: Beech Bark 

Disease)
80 Forest Pest Insects in North America:

Images of Beech Scale

Figure 2. Close up of beech scales under their woolly coverings (left) and 

with wool removed, showing orange scale bodies (right). (Both photos: Chris 

Malumphy, The Food and Environment Research Agency, Bugwood.org)

Figure 3. First instar nymph (crawler) of beech scale. (Joseph O’Brien, USDA 

Forest Service, Bugwood.org)

Figure 4. View of trunk of 

American beech infested with 

beech scale (light colored 

material). (Joseph O’Brien, USDA 

Forest Service, Bugwood.org)
A Photographic Guide 81

Figure 5. Beech scale on bark of severely damaged American beech (left) (note 

also lumpy cankers on trunk caused by beech bark disease); close up of colonies 

of beech scale (right). (Left: Joseph O’Brien, USDA Forest Service, Bugwood.org; 

right: Chris Malumphy, The Food and Environment Research Agency, 

Bugwood.org)

Figure 6. Beech trees in forest killed by beech bark disease. (Joseph O’Brien, 

USDA Forest Service, Bugwood.org)

Figure 7. Cracked bark of tree with beech bark disease (left) compared to smooth 

grey bark of healthy American beech (right). (Both photos: Joseph O’Brien, USDA 

Forest Service, Bugwood.org)

Images of Beech Scale

(continued)
82 Forest Pest Insects in North America:

Figure 9. Dark weeping spots are also a sign of beech bark disease. (Joseph 

O’Brien, USDA Forest Service, Bugwood.org)

Figure 10. Discoloration under bark due to Neonectria cankers. (Joseph O’Brien, 

USDA Forest Service, Bugwood.org)

Figure 8. Bark cracking and 

growth of epiphytes (here, 

moss) on trunk are other 

signs of beech bark disease. 

(Milan Zubrik, Forest 

Research Institute - Slovakia, 

Bugwood.org)

Images of Beech Scale

(continued)
A Photographic Guide 83

Figure 11. Orange fruiting 

bodies of Neonectria on 

beech bark. (Andrej Kunca, 

National Forest Centre - 

Slovakia, Bugwood.org)

Images of Beech Scale

(continued)

No parasitoids of this scale are known from either North America or 

Europe. Studies in both regions found only generalist predators attacking 

the scale. Currently efforts to find parasitoids are underway in the 

Caucasus Mountains, the region now believed to be at least part of the 

native range of the scale.

http://www.ecostudies.org/people_sci_lovett_beech_bark_disease.html; 

ecosystem effects of beech bark disease.

http://nrs.fs.fed.us/disturbance/invasive_species/bbd_resistant_beech/; 

research on resistance in American beech to beech bark disease.

http://threatsummary.forestthreats.org/threats/threatSummaryViewer.

cfm?threatID=117

http://en.wikipedia.org/wiki/Beech_bark_disease

http://www.sel.barc.usda.gov/catalogs/eriococc/Cryptococcusfagisuga.

htm; ScaleNet catalog, giving a complete list of all recorded natural 

enemies, hosts, and distribution records, and an index to all other 

information published on this insect. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Beech Scale
84 Forest Pest Insects in North America:

Van Driesche, R.G., S. Healy, and R.C. Reardon. 1996. Biological 

Control of Arthropod Pests of the Northeastern and North Central 

Forests in the United States: A Review and Recommendations.

FHTET-96-19. USDA Forest Service, Morgantown, West Viriginia, 

USA: 20-22.

Forrester, J.A., G.G. McGee, and M.J. Mitchell. 2003. Effects of beech 

bark disease on aboveground biomass and species composition in a 

mature northern hardwood forest, 1985 to 2000. Journal of the Torrey 

Botanical Society 130(2): 70-78.

Gwiazdowski, R.A., R.G. Van Driesche, A. Desnoyers, S. Lyon, San-an 

Wu, N. Kamatad and B.B. Normark. 2006. Possible geographic origin 

of beech scale, Cryptococcus fagisuga (Hemiptera: Eriococcidae), an 

invasive pest in North America. Biological Control 39: 9-18.

Articles on Beech Scale
A Photographic Guide 85

29. Gillette’s Eriococcin, Eriokermes gillettei (Tinseley) (Hemiptera: 

Kermesidae, formerly Eriococcidae)

Gillette’s eriococcin, Eriokermes gillettei (Tinseley) (syn. is Eriococcus 

gillettei), is a native North American scale. This species is found on 

native junipers (Juniperus) but is not damaging. Occasionally higher 

densities develop on junipers planted as ornamentals. Adult females are 

yellowish before forming an ovisac but then turn brownish purple. In 

Maryland, there is one generation per year and the scale overwinters in 

the egg stage. 

This scale is restricted to feeding on species of juniper (Juniperus).

This scale is known from Florida, Maryland, Virginia, and several 

western states, but likely has a larger U.S. distribution, including most of 

the southeastern United States. 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Image of 

Gillette’s Eriococcin

Figure 1. Gillette’s eriococin, 

Eriokermes gillettei, on 

juniper. (Raymond Gill, 

California Department 

of Food and Agriculture, 

Bugwood.org)

Parasitoids of this scale have not been reported but its characteristic 

low density in natural habitats suggests it may be kept under control by 

specialized parasitoids. 

http://www.sel.barc.usda.gov/catalogs/kermesid/Eriokermesgillettei.htm; 

ScaleNet catalog, giving a complete list of all recorded natural enemies, 

hosts, and distribution records, and an index to all other information.

Miller, D.R. and G.L. Miller. 1993. Description of a new genus of scale 

insect with a discussion of relationships among families related to the 

Kermesidae (Homoptera: Coccoidea). Systematic Entomology 18: 

237-251. (This article introduced the current name of the species.)

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Gillette’s Eriococcin

Articles
86 Forest Pest Insects in North America:

30. Pine Bast Scale, Matsucoccus matsumurae (Kuwana) (Hemiptera: 

Matsucoccidae)

Pine bast scale, Matsucoccus matsumurae (Kuwana), (formerly referred 

to as red pine scale, Matsucoccus resinosae, in the United States) is a 

Japanese scale that is invasive in the United States. Along with six Asian 

species of pines, it attacks red pine (Pinus resinosa Sol. ex Aiton), its 

only native North American host. It occurs in plantations of red pine 

planted south of their native range in Connecticut, New York, New 

Jersey, and Pennsylvania. The infested area is expanding slowly.

Pine bast scale attacks several Asian pines, but its only North American 

native host is red pine (P. resinosa).

This scale is native to Japan and is invasive in China, South Korea, 

Sweden, and eastern North America. 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Image of 

Pine Bast Scale

Figure 1. Pine bast scale, 

Matsucoccus matsumurae. 

(USDA APHIS PPQ CPHST)

Natural enemies associated with pine bast scale in North America are 

principally generalist predators (coccinellids, anthocorid bugs, and 

cecidomyiid flies). In China, predation on eggs and young nymphs by the 

anthocorid Elatophilus nipponensis Hiura is a critical factor affecting the 

pest. Also in both China and Japan, the generalist predatory coccinellid 

Harmonia axyridis Pallas is believed to suppress this scale’s density. This 

coccinellid in now found as an invasive species throughout the range of 

red pine scale in the northeast United States but definitive studies on its 

impact on this scale are lacking. 

http://www.sel.barc.usda.gov/catalogs/matsucoc/

Matsucoccusmatsumurae.htm; ScaleNet catalog, giving a complete list of 

all recorded natural enemies, hosts, and distribution records, and an index 

to all other information published on this insect. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Pine Bast Scale
A Photographic Guide 87

Cheng, H.Y. and W.J. Ming. 1979. Population dynamics and 

biological control of Matsucoccus matsumurae Kuwana (Homoptera: 

Margarodidae). Acta Entomologica Sinica 22: 149-155.

McClure, M.S. 1986. Role of predators in regulation of endemic 

populations of Matsucoccus matsumurae (Homoptera: Margarodidae) in 

Japan. Environmental Entomology 15: 976-983.

Ming, W.J., Q.J. Ge, and H.Y. Zheng. 1983. Studies of some major 

predaceous natural enemies of Matsucoccus matsumurae (Kuwana). 

Journal of Nanjing Technological College of Forest Products 3: 19-29.

Articles
88 Forest Pest Insects in North America:

31. Tuliptree Scale, Toumeyella liriodendri (Gmelin) (Hemiptera: Coccidae)

Tuliptree scale, Toumeyella liriodendri (Gmelin), is native to the eastern 

United States, where it is widely distributed. It also occurs in urban areas 

in California, where it is invasive. It mainly feeds on twigs of tuliptree 

(Liriodendron tulipifera L.) and magnolia (Magnolia). Heavy infestations 

are common and these can (1) kill seedlings, (2) destroy leaders or 

branches leading to bushy form, and (3) remove nutrients and lower tree 

vigor. The scale has one generation per year except in the southern part 

of its range and it generally overwinters as young nymphs on twigs.

This scale feeds on tuliptree (L. tulipifera) and species of magnolia 

(Magnolia), as well as hosts in eight other plant families. 

This scale is found from New York south to Florida and west to the 

Mississippi River (see Burns and Donley [1970] for a distribution map), 

and has invaded urban areas of California. 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Figure 1. Group of mature female tuliptree scales, Toumeyella liriodendri, on twig 

of host. (A. Steven Munson, USDA Forest Service, Bugwood.org)

Images of 

Tuliptree Scale
A Photographic Guide 89

Figure 2. Mature female of 

tuliptree scale surrounded 

by crawlers. (Gerald J. 

Lenhard, Louiana State Univ, 

Bugwood.org)

Figure 3. Overwintering second instar nymphs of tuliptree scale on twig. 

(Lacy L. Hyche, Auburn University, Bugwood.org)

Figure 4. Empty cast skins of male “pupae” of tuliptree scale. (Lacy L. Hyche, 

Auburn University, Bugwood.org)

Images of Tuliptree 

Scale (continued)
90 Forest Pest Insects in North America:

Many species of parasitoids and predators are reported attacking tuliptree 

scale in the United States, but at the same time, the scale is reported as 

frequently being abundant and damaging. Its ability to thrive in spite of 

its many enemies may be because it is very frequently tended by ants. 

http://www.fs.fed.us/r6/nr/fid/fidls/fidl-92.pdf; USDA Forest Service 

leaflet #92 with photos of damage to tree form.

http://ento.psu.edu/extension/factsheets/tuliptree-scale; fact sheet from 

Pennsylvania State University; discusses control.

http://www.ca.uky.edu/entomology/entfacts/ef435.asp; fact sheet from 

University of Kentucky; discusses control.

http://cfextension.ifas.ufl.edu/agriculture/nursery_production/documents/

Magnolia.pdf; University of Florida; discusses control on magnolia.

http://www.sel.barc.usda.gov/catalogs/coccidae/Toumeyellaliriodendri.

htm; ScaleNet catalog, giving a complete list of all recorded natural 

enemies, hosts, and distribution records, and an index to all other 

information published on this insect. 

Burns, D.P. and D.E. Donley. 1970. Biology of the tuliptree scale, 

Toumeyella liriodendri (Homoptera: Coccidae). Annals of the 

Entomological Society of America 63: 228-235.

Simpson, J.D. and P.L. Lambdin. 1983. Life history of the tuliptree 

scale, Toumeyella liriodendri (Gmelin), on yellow-poplar in Tennessee. 

Tennessee Farm and Home Science 125: 2-5.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Tuliptree Scale

Articles
A Photographic Guide 91

32. Pine Tortoise Scale, Toumeyella parvicornis (Cockerell) (Hemiptera: 

Coccidae)

The pine tortoise scale, Toumeyella parvicornis (Cockerell), is native 

to the United States and is found widely over the northeastern, north 

central, and southeastern portions of the country. It is also invasive in 

Puerto Rico and the Turks and Caicos Islands in the Caribbean. It has 

one generation per year in the northern parts of its range, and four or 

more generations in the southern portions. The first instars (crawlers) 

are the mobile dispersal stage. Crawlers eventually settle either on the 

shoot or on the needles. The choice of settling site may be host-specific. 

Settled females on shoots are brown with dark markings and have 

the hemispherical tortoise shape for which they are named. Females 

developing on the needles are elongate and initially are light green with 

darker green stripes, eventually turning brownish. The males develop on 

the same plant part as the females. Adult males are winged and smaller 

than the females. The scales excrete honeydew, which provides a growth 

medium for sooty mold. Heavy infestations may result in tree mortality.

Most pines within its range can be infested by this scale but important 

hosts include Scotch (Pinus sylvestris), Jack (P. banksiana), Virginia 

(P. virginiana), loblolly (P. taeda), and slash (P. elliottii) pines. 

This scale is found from eastern New York, south to Florida and west 

through the Dakotas, Colorado, and Texas wherever its hosts are found. 

It is also known to occur in Manitoba and Ontario, Canada, and has been 

introduced into parts of the Caribbean.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of 

Pine Tortoise Scale

Figure 1. Pine tortoise scales, Toumeyella parvicornis; note the tortoise shell 

shape and color pattern. (Lacy L. Hyche, Auburn University, Bugwood.org)
92 Forest Pest Insects in North America:

Images of Pine Tortoise 

Scale (continued)

Figure 2. Sooty mold growing on honeydew excreted by pine tortoise scales 

on pine needles. (R. Scott Cameron, Advanced Forest Protection, Inc., 

Bugwood.org)

Figure 3. Adult (shoot form) of the female pine tortoise scale with emerging 

crawlers (left) and the needle form female with settled crawlers (right). 

(Left: Jill O’Donnell, MSU Extension, Bugwood.org; right: Albert (Bud) Mayfield, 

USDA Forest Service, Bugwood.org) 

Figure 4. Settled crawlers of pine tortoise scale. (Lacy L. Hyche, Auburn 

University, Bugwood.org)
A Photographic Guide 93

Figure 5. Young nymphs of pine tortoise scale. (Lacy L. Hyche, Auburn 

University, Bugwood.org)

Figure 7. Ladybird beetles feeding on pine tortoise scales. (Lacy L. Hyche, 

Auburn University, Bugwood.org)

Figure 6. Damage to Virginia 

pine from pine tortoise scale. 

(Lacy L. Hyche, Auburn 

University, Bugwood.org)

Images of Pine Tortoise 

Scale (continued)
94 Forest Pest Insects in North America:

Many species of parasitoids and predators are reported attacking pine 

tortoise scale in the United States, and in most settings, natural enemies 

are sufficient to maintain the scale at low densities. Damaging scale 

populations develop either when ants tend scale colonies (see Wilkinson 

and Chellman, 1979) or where dust or insecticides reduce natural enemy 

numbers in seed orchards or Christmas tree farms (see Clarke et al., 

1992).

http://www.na.fs.fed.us/spfo/pubs/fidls/pine_tort_scale/pine_tort_scale.

htm; USDA FS leaflet, with information on biology, life cycle and 

control of this scale. 

http://www.plantpath.cornell.edu/trees/PTortSc.html; fact sheet from 

Cornell University.

http://www.entomology.umn.edu/cues/Web/186PineTortoiseScale.pdf; 

fact sheet from University of Minnesota.

Wilkinson, R.C. and C.W. Chellman. 1979. Toumeyella scale, red 

imported fire ant, reduce slash pine growth. Florida Entomologist 62: 

71-72.

Clarke, S.R., J.F. Negron, and G.L. DeBarr. 1992. Effects of four 

pyrethroids on scale insect (Homoptera) populations and their natural 

enemies in loblolly and shortleaf pine seed orchards. Journal of 

Economic Entomology 85: 1246-1252.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Pine Tortoise Scale

Articles
A Photographic Guide 95

33. Tessellated Scale, Eucalymnatus tessellatus (Signoret) (Hemiptera: 

Coccidae)

Tessellated scale, Eucalymnatus tessellatus (Signoret), occurs as an 

invasive species in the southern United States and parts of Africa, 

Australia, Asia and Europe. It is believed to be native to South America. 

The adult female is oval or pear-shaped and is reddish to dark brown in 

color. There are one or two generations per year. All scales are female 

and give birth directly to crawlers through egg retention.

Tessellated scale has an extremely broad host range, attacking more 

than 50 families of plants, including many monocots and dicots used as 

ornamentals or as fruit trees. Common host plants include palms, figs, 

and mango (Mangifera indica L.). 

In the United States, this scale is found outdoors in various southern 

states, particularly Florida. In northern areas, the scale is found in 

greenhouses. 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Image of 

Tesselated Scale

Figure 1. Closer view of a 

single adult of tessellated 

scale, Eucalymnatus 

tessellatus. (United States 

National Collection of Scale 

Insects Photographs Archive, 

USDA Agricultural Research 

Service, Bugwood.org)

The parasitic wasp Metaphycus stanleyi Compere is a natural enemy of 

tessellated scale. 

http://edis.ifas.ufl.edu/pdffiles/IN/IN82600.pdf; fact sheet of the 

University of Florida. 

http://www.entomology.umn.edu/cues/inter/inmine/Scalet.html; fact 

sheet from University of Minnesota. 

http://www.sel.barc.usda.gov/catalogs/coccidae/Eucalymnatustessellatus.

htm; ScaleNet catalog, giving a complete list of all recorded natural 

enemies, hosts, and distribution records, and an index to all other 

information published on this insect. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Tesselated Scale
96 Forest Pest Insects in North America:

Ray, C.H. and M.L. Williams. 1981. Redescription and lectotype 

designation of the tessellated scale, Eucalymnatus tessellatus (Signoret) 

(Homoptera: Coccidae). Proceedings of the Entomological Society of 

Washington 83: 230-244. (Provides descriptions of three immature stages 

and adult female, a key for the separation of instars, a list of hosts, and 

information on distribution.).

Article on Tesselated Scale
A Photographic Guide 97

34. Elongate Hemlock Scale, Fiorinia externa Ferris (Hemiptera: 

Diaspididae)

Elongate hemlock scale, Fiorinia externa Ferris, an invasive scale in 

the USA, is native to Japan and China that is a pest of eastern hemlock 

(Tsuga canadensis [L.] Carrière) in the eastern United States. The 

scale has long-lived adult females that reproduce slowly over much of 

the year, leading to a population with highly overlapping life stages. 

In New England there is one generation per year but there are two in 

North Carolina. Damage can be serious in the eastern United States on 

hemlock, with densities one- to three-thousand-fold higher than in Japan, 

causing chlorosis, needle drop, and tree mortality.

This scale attacks principally eastern hemlock (T. canadensis), but 

sometimes species of spruce or fir (Abies), Douglas-fir (Pseudotsuga

menziesii [Mirbel] Franco), or yew (Taxus) are infested.

Elongate hemlock scale is native to Japan and China but is invasive in 

North America from New Hampshire to Georgia and west to Michigan, 

within range of eastern hemlock. This scale is also invasive in Europe 

(UK, France).

Orientation to Pest

Hosts Commonly Attacked

Distribution

Figure 1. North American distribution of elongate hemlock scale, Fiorinia externa. 

(USDA Forest Service - AFPE Online Mapping)
98 Forest Pest Insects in North America:

Images of Elongate

Hemlock Scale

Figure 2. Heavy infestation of elongate hemlock scale on eastern hemlock, 

showing many white males and some brown adult females. (Eric R. Day, Virginia 

Polytechnic Institute and State University, Bugwood.org)

Figure 3. Adult female 

elongate hemlock scales 

(brown). (Kristopher Abell, 

University of Massachusetts, 

Bugwood.org)

Figure 5. Settled first 

instar nymphs (“crawlers”, 

see light colored, upper 

right quarter of photo) of 

elongate hemlock scale. 

(Rich Cowles, Connecticut 

Agricultural Experiment 

Station)

Figure 4. Eggs (yellow) of 

elongate hemlock scale 

inside opened scale cover of 

adult female. (Pennsylvania 

Department of Conservation 

and Natural Resources - 

Forestry Archive, 

Bugwood.org)
A Photographic Guide 99

Figure 6. Second instar nymph (mid sized, yellow stages) of elongate hemlock 

scale; also showing brown adult females and white males. (Pennsylvania 

Department of Conservation and Natural Resources - Forestry Archive, 

Bugwood.org)

Figure 7. Adult female elongate hemlock scales (left) with parasitoid emergence 

holes; adult Encarsia citrina (right), an often abundant but generally ineffective 

polyphagous parasitoid found attacking elongate hemlock scale in both North 

America and Japan. (Both photos, Kristopher Abell, University of Massachusetts, 

Bugwood.org)

Figure 8. Cybolephalus nr. 

nipponicus Endrody-Younga, 

an introduced predatory 

beetle that sometimes preys 

on elongate hemlock scale. 

(Pennsylvania Department 

of Conservation and Natural 

Resources - Forestry 

Archive, Bugwood.org)

Images of Elongate

Hemlock Scale (continued)
100 Forest Pest Insects in North America:

Studies by Kristopher Abell (Ph.D. dissertation, Entomology, University 

of Massachusetts, 2010) have shown that Encarsia citrina (Crawford), 

a polyphagous aphelinid parasitoid commonly found attacking elongate 

hemlock scale in both eastern North America and Japan, is only one of 

many Encarsia, Aphytis and other parasitoid species that attack the scale 

in Japan, which, except for E. citrina, are not present in North America. 

In addition, this same research has confirmed that E. citrina and the 

susceptible life stage of the scale are asynchronous throughout North 

America, even where two complete generations of the scale occur as 

Japan. The lack of synchrony was attributed to overlapping generations 

and delayed senescence of the adult female scale. Importations of species 

of parasitoids from Japan has potential to reduce densities of elongate 

hemlock scale in North America. 

http://ento.psu.edu/extension/factsheets/elongate-hemlock-scale; fact 

sheet from Pennsylvania State University.

http://www.na.fs.fed.us/spfo/pubs/pest_al/ehscale/ehscale.htm; fact sheet 

from USDA Forest Service, Northeastern Area.

http://www.hgic.umd.edu/_media/documents/hg81.pdf; fact sheet from 

Maryland Cooperative Extension Service.

http://www.fcla.edu/FlaEnt/fe89p527.pdf; article on results of predator 

survey in North Carolina and Tennessee, USA.

McClure, M.S. and M.B. Fe. 1977. Fiorinia externa and Tsugaspidiotus

tsugae (Homoptera: Diaspididae): distribution, abundance, and new 

hosts of two destructive scale insects of eastern hemlock in Connecticut. 

Environmental Entomology 6: 807-811.

Preisser, E.L., J.S. Elkinton, and K. Abell. 2008. Evolution of increased 

cold tolerance during range expansion of the elongate hemlock 

scale Fiorinia externa Ferris (Hemiptera: Diaspididae). Ecological 

Entomology 33: 709-715.

Abell, K. 2010. Population dynamics and biological control of elongate 

hemlock scale, Fiorinia externa. Ph.D. dissertation, Entomology, 

University of Massachusetts, Amherst, Massachusetts. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Elongate Hemlock Scale

Articles
A Photographic Guide 101

35. Oystershell Scale, Lepidosaphes ulmi (L.) (Hemiptera: Diaspididae)

Oystershell scale, Lepidosaphes ulmi (L.), is a widespread species 

of uncertain origin, now found in almost every temperate area in the 

world. It is known to be invasive in North America, Australia, New 

Zealand, South Africa, and Japan. It is also found, potentially as a native 

species, in North Africa and throughout temperate regions of Europe 

and Asia. It is one of the most polyphagous insects known, reported 

from 72 different families of plants. Oystershell scale is found mostly 

on branches and trunks of broadleaf shrubs and trees, in both natural 

habitats and planted landscapes. The coloration of the adult female varies 

with the host species. The life history of the species also varies with 

host, with more generations per year on some hosts and fewer on others. 

The species overwinters as eggs on all host species. Dense populations 

may kill branches, whole trees, or even forest stands. This variable 

cosmopolitan species may in reality be a complex of several biotypes 

that are being lumped together (see Gharib, 1978). Some populations are 

parthenogenetic, consisting entirely of females.

Oystershell scale is a polyphagous species that attacks many broad leaf 

woody species, including apple (Malus), ash (Fraxinus), beech (Fagus), 

birch (Betula), elm (Ulmus), maple (Acer), poplar (Populus), species of 

Prunus, and willow (Salix). 

This invasive species is found throughout the United States and southern 

Canada.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of 

Oystershell Scale

Figure 1. Oystershell scale, 

Lepidosaphes ulmi, is named 

for the shape of the scale 

covering, resembling an 

oyster shell. (United States 

National Collection of Scale 

Insects Photographs Archive, 

USDA Agricultural Research 

Service, Bugwood.org)
102 Forest Pest Insects in North America:

Images of Oystershell 

Scale (continued)

Figure 4. One female oystershell scale surrounded by recently settled crawlers. 

(Whitney Cranshaw, Colorado State University, Bugwood.org)

Figure 3. Adult oystershell scale inverted to reveal masses of white eggs, 

the overwintering stage. (Whitney Cranshaw, Colorado State University, 

Bugwood.org)

Figure 2. View of dense 

colony of oystershell scales. 

(United States National 

Collection of Scale Insects 

Photographs Archive, USDA 

Agricultural Research 

Service, Bugwood.org)
A Photographic Guide 103

Figure 5. Dense population of oystershell scale on aspen in Colorado. (Whitney 

Cranshaw, Colorado State University, Bugwood.org)

Figure 6. Willows in natural habitat killed by oystershell scale. (USDA Forest 

Service - Ogden Archive, USDA Forest Service, Bugwood.org)

Images of Oystershell 

Scale (continued)
104 Forest Pest Insects in North America:

Despite a large literature on this species, relatively little is known 

about its potential for classical biological control because the species 

is principally of concern in apple orchards, where the perception is that 

no scales can be tolerated. But in a forestry or shade tree context, that 

concern should not apply. Two natural enemies are frequently mentioned 

in connection with this scale, the predatory mite Hemisarcoptes malus

(Shimer) and the aphelid parasitoid Aphytis mytilaspidis (Le Baron). 

While both of these occur in North America, neither were deliberately 

introduced. Indeed, little to no work has been done to determine the 

native range of this scale (likely Central Asia or the Russian Far East) 

and then determine which species of natural enemies in that area are 

most effective against low density scale populations. Also, this species 

of scale may in reality be a complex of species or races and this should 

be sorted out with DNA methods to show which races are of concern in 

North America and where are they found in the native range. Finally, 

even some natural enemies like A. mytilaspidis, which is present in the 

United State, might be improved by a new introduction of the species 

that is better adapted to cold areas, where the existing race does not do 

well but where much of the damage from oystershell scale occurs. 

http://www.ext.colostate.edu/pubs/insect/05513.html; fact sheet from 

Colorado State University.

http://ento.psu.edu/extension/factsheets/oystershell-scale; fact sheet from 

Pennsylvania State University.

http://www.sel.barc.usda.gov/catalogs/diaspidi/Lepidosaphesulmi.htm; 

ScaleNet catalog, giving a complete list of all recorded natural enemies, 

hosts, and distribution records, and an index to all other information 

published on this insect.

Gharib, B. 1978. On two new distinct biological races of Lepidosaphes 

ulmi L. (Homoptera, Coccoidea, Diaspidinae). Comptes Rendus 

Hebdomadaires des Seances de l’Academie des Sciences, D 286(18): 

1313-1314. (In French).

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Oystershell Scale

Articles
A Photographic Guide 105

San José scale, Diaspidiotus perniciosus (Comstock), is native to Asia 

(northern China, Korea, the Russian Far East) and is invasive in North 

America and in other temperate and subtropical areas throughout the 

world. It is found throughout the United States and Canada. It is a highly 

polyphagous species, reported from 43 different families of plants, 

but is economically most troublesome on members of the rose family. 

The scale has multiple generations per year in many areas and, if not 

suppressed by parasitoids, can be very damaging, killing heavily infested 

trees. It is not a pest in native forests, but is common on ornamental, 

shade, and fruit trees. 

Common hosts include many rosaceous plants, especially apple (Malus), 

plums and cherries (Prunus), peaches (P. persica (L.) Batsch), almonds 

(P. dulcis [Mill.] D.A.Webb), pear (Pyrus), and Pyracantha. 

This invasive species, while native to northeastern Asia, is found 

throughout North America, and more generally around the world in 

temperate and subtropical regions.

36. San José Scale, Diaspidiotus perniciosus (Comstock) (Hemiptera: 

Diaspididae)

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of 

San José Scale

Figure 1. Adults (left) of San José scale, Quadraspidiotus perniciosus; females 

(right) with scale cover removed to show scale body. (Left: United States National 

Collection of Scale Insects Photographs Archive, USDA Agricultural Research 

Service, Bugwood.org; right: Washington State University)
106 Forest Pest Insects in North America:

Images of San José 

Scale (continued)

Figure 2. Crawler of San José scale. (Washington State University)

Figure 3. Nymphs of San 

José scale settled around 

two adult females. (United 

States National Collection of 

Scale Insects Photographs 

Archive, USDA Agricultural 

Research Service, 

Bugwood.org)

Figure 4. Adult male of San José scale (left); drawing of male (right). 

(Left: Washington State University; right: FCIT - http://etc.usf.edu/clipart)
A Photographic Guide 107

Figure 5. View of twig 

infested by San José scale. 

(United States National 

Collection of Scale Insects 

Photographs Archive, USDA 

Agricultural Research 

Service, Bugwood.org)

Figure 6. Damage on apples from San José scale. Note both scales and red 

discoloration around scales. (Central Science Laboratory, Harpenden Archive, 

British Crown, Bugwood.org)

Figure 7. Encarsia perniciosi, an important parasitoid of San José scale. 

(HYPPZ)

Images of San José 

Scale (continued)
108 Forest Pest Insects in North America:

Figure 8. Twice stabbed 

ladybird, Chilocorus orbus

Drea, a predator of San José 

scale. (Jack Kelly Clark, 

University of California 

- Statewide IPM Program, 

Bugwood.org)

As San José scale moved around the world into various apple growing 

regions, it came in contact with local parasitoids, some of which adopted 

this scale as a new host. Also, several of the Asian parasitoids associated 

with this scale in its native range moved naturally with the scale to new 

regions (on apple breeding stock). Worldwide, the list of parasitoids is 

long and complex (see Van Driesche et al., 1996, pp. 28-31, see under 

web links for URL). Of these many parasitoids, the most important 

in North America are two North American species, Aphytis diaspidis

(Howard) and A. mytilaspidis (Le Baron) and two Chinese parasitoids, 

Encarsia perniciosi (Tower) and Coccophagoides kuwanae (Silvestri). 

In much of the United States, this scale is now generally held at 

acceptable levels by some combination of these parasitoids, unless they 

are absent naturally or have been suppressed by local use of pesticides. 

http://www.fs.fed.us/foresthealth/technology/pdfs/FHTET_96_19.pdf; 

Van Driesche et al. 1996; see pages 28-31.

http://www.virginiafruit.ento.vt.edu/SJS.html; fact sheet from Virginia 

Tech.

http://www.inra.fr/hyppz/RAVAGEUR/6quaper.htm; good photographs.

http://jenny.tfrec.wsu.edu/opm/displaySpecies.php?pn=490; Washington 

State University—lengthy, high quality fact sheet; excellent photo gallery 

on species.

http://www.nysipm.cornell.edu/factsheets/treefruit/pests/sjs/sjs.asp; fact 

sheet from Cornell University.

http://www.ipm.ucdavis.edu/PMG/r4301911.html; University of 

California at Davis fact sheet covering life history and use of pesticides 

for control on fruit.

http://www.canr.msu.edu/vanburen/sanjosefs.html; fact sheet from 

Michigan State University.

http://www.caf.wvu.edu/kearneysville/pest_month/insectfocusapril98.

htm; fact sheet of University of California. 

http://www.sel.barc.usda.gov/catalogs/diaspidi/Diaspidiotusperniciosus.

htm; ScaleNet catalog, giving a complete list of all recorded natural 

enemies, hosts, and distribution records, and an index to all other 

information published on this insect. 

Images of San José 

Scale (continued)

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on San José Scale
A Photographic Guide 109

CAB (Commonwealth Agricultural Bureaux). 1986. International 

Institute of Entomology, Distribution maps of pests, No. 7. 

Commonwealth Agricultural Bureaux, United Kingdom. [Map of world 

distribution of San José scale].

Articles
110 Forest Pest Insects in North America:

37. Willow Scale, Diaspidiotus gigas (Thiem and Gerneck) (Hemiptera: 

Diaspididae)

Willow scale, Diaspidiotus gigas (Thiem and Gerneck), is an invasive 

scale found in North America. It is also widely distributed across the 

northern temperate zone in the Old World, from Algeria and western 

Europe to Siberia and China. It has one generation per year in the 

northern United States and overwinters as partly grown nymphs or young 

adults. It feeds on branches of species of willow (Salix) and poplar 

(Populus) and is found on both shade trees and in natural vegetation. 

Willow scale feeds on species of willow (Salix) and poplar (Populus).

This scale is found across the United States, with specimens recorded 

from both western parts of the country (Oregon, Washington, Idaho, 

Montana, Colorado, Utah, and Wyoming), the midwest (Wisconsin, 

Ohio) and the northeast (New York, Pennsylvania, Rhode Island). It is 

also found in eastern Canada (Nova Scotia, New Brunswick, Ontario). 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of Willow Scale

Figure 1. Mixed stages of willow scale, Diaspidiotus gigas, on trunk of an aspen 

tree. (Whitney Cranshaw, Colorado State University, Bugwood.org)

Figure 2. Close up view 

of mixed stages of willow 

scale on aspen. (Whitney 

Cranshaw, Colorado State 

University, Bugwood.org)
A Photographic Guide 111

Figure 3. Crawlers of willow scale escaping from female scale. (Bob Hammon, 

Bugwood.org)

Figure 5. Two views of damage from willow scale to aspen bark; left view of 

whole trunk showing “bubbling” or pitting effect on bark (middle of photo) and 

on right, close up of damage. (Both photos: Whitney Cranshaw, Colorado State 

University, Bugwood.org)

Figure 4. Overwintering stage (2nd instar nymphs) of willow scale on bark. 

(Whitney Cranshaw, Colorado State University, Bugwood.org)

Images of Willow Scale

(continued)
112 Forest Pest Insects in North America:

Figure 6. Aspen trees in 

Aspen, Colorado, that are 

heavily infested with willow 

scale. (Bob Hammon, 

Bugwood.org)

Images of Willow Scale

(continued)

Figure 7. Chilocorus 

kuwanae, a predator of 

willow scale in its native 

range in China. (Tom Murray, 

Bugwood.org)
A Photographic Guide 113

The aphelinid parasitoids Pteroptrix longgiclava (Girault) and Encarsia 

gigas (Tshumakova) attack willow scale in China and are attracted to 

volatiles from the scale, suggesting these may be specialized species of 

value in biological control. Other parasitoids known to attack this scale 

in Europe or other regions include Aphytis mytilaspidis (Le Baron), 

Pteroptrix dimidiatus (Westwood), and Azotus matritensis Merc. Aphytis 

mytilaspidis, however, is a widely distributed polyphagous species that 

attacks many diaspidids. Predators known to feed on this scale include 

Chilocorus kuwanae Silvestri (an Asian ladybird already introduced 

into North America for control of another invasive scale, Unaspis 

euonymi [Comstock]), Chilocorus bipustulatus (L.) and Coccinella 

bipunctata ( L.). The native North American species Chilocorus stigma

has been observed feeding on D. gigas in Colorado. Other potential 

willow scale predators known from Europe include the predatory bugs 

Loricula pselaphiformis Curt. and Loricula elengatula Baerensprung 

(Microphysidae) and the anthocorids Ectemnus nigriceps E. Wagner and 

Temnostethus longirostris (Horv.).

http://www.fs.fed.us/r1-r4/spf/fhp/publications/bystate/BFO-PR-08-01_

woodriver.pdf; photos and description of recent problems on aspen from 

willow scale in Idaho.

http://wci.colostate.edu/shtml/AspenScale.shtml; Colorado State 

University factsheet.

http://www.sel.barc.usda.gov/catalogs/diaspidi/Diaspidiotusgigas.htm; 

ScaleNet catalog, giving a complete list of all recorded natural enemies, 

hosts, and distribution records, and an index to all other information 

published on this insect. 

Lelláková-Dusková, F. 1963. The morphology, metamorphosis, and 

lifecycle of the scale insect Quadraspidiotus gigas (Thiem and Gerneck). 

Acta Entomologica Musei Nationalis Prague 5: 611-648.

Nakahara, S. 1982. A Checklist of the Armored Scales of the Coterminous 

United States. Plant Protection and Quarantine Animal and Plant Health 

Inspection Service, United States Department of Agriculture. 110 p.

Chi, D.F., S.C. Yan, X.H. Zhao, and Z.H. Wen. 2003 The taxis of chalcid 

parasitoids to their host and analysis of the volatile[s] from fixed first 

instar nymph[s] of Quadraspidiotus gigas (Thiem & Gerneck). Journal 

of Northeast Forestry University 31(2): 20-22.

Chi, D.F., R.O. Rubio, S.C. Yan, D.D. Zhang, and Z.H. Wen. 2002. 

Foraging behavior of parasitoid chalcid to the essential oil from bark of 

Populus pseudo-simonii × P. nigra and Quadraspidiotus gigas. Journal 

of Forestry Research 13(4): 255-259.

Ma, L., C.D. Li, J.Q. Liu, Y. Sun, X.L. Wang, Y.J. Ji, W.S. Du, L. 

Yang, G.L. Su, and B.H. Zhao. 1997. Predatory function of Chilocorus 

kawanae Silvestri on Quadraspidiotus gigas (Thiem et Gerneck). 

Journal of Northeast Forestry University 25(2): 64-67.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Willow Scale

Articles
114 Forest Pest Insects in North America:

38. Camphor Scale, Pseudaonidia duplex (Cockerell) (Hemiptera: 

Diaspididae)

Camphor scale (also called camellia scale), Pseudaonidia duplex

(Cockerell), is an invasive Asian scale found in the southern United 

States. The scale infests leaves, twigs and fruit of various plants, but 

especially the camphor tree (Cinnamomum camphora [L.] Sieb.). In Asia, 

it is a pest of tea plantations. In Louisiana, the scale has three generations 

per year and overwinters primarily as mated adult females.

This scale feeds on over 200 different host plants in Louisiana alone, 

including the camphor-tree (C. camphora) and some species of citrus 

(Citrus). In Asia it is a pest of tea (Camellia sinensis [L.] Kuntze). 

The United States distribution of this scale reaches from Florida and 

Georgia, west to Texas. 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of Camphor Scale

Figure 1. Camphor scale, Pseudaonidia duplex, adults; adult and one nymph on 

fruit (left) and adults and several nymphs on foliage (right). (Both photos: Lyle 

Buss, University of Florida, Bugwood.org)

Figure 2. Camphor scales on Virginia creeper (Parthenocissus quinquefolia [L.] 

Planch.) leaf. (Lyle Buss, University of Florida, Bugwood.org)
A Photographic Guide 115

Figure 3. Camphor scales on wax-myrtle (Myrica spp.), with scale covers 

turned over to reveal scale bodies (orange). (Lyle Buss, University of Florida, 

Bugwood.org)

Figure 4. Camphor scales on wax-myrtle twig. (Lyle Buss, University of Florida, 

Bugwood.org)

In Taiwan in tea plantations, this scale is attacked by the parasitoid 

Neochrysocharis sp., which can cause 42-61 percent mortality 

(Shiao, 1978).

http://www.doacs.state.fl.us/pi/enpp/ento/entcirc/ent028.pdf; a Florida 

entomology circular that gives a host list.

http://www.sel.barc.usda.gov/catalogs/diaspidi/Pseudaonidiaduplex.htm; 

ScaleNet catalog, giving a complete list of all recorded natural enemies, 

hosts, and distribution records, and an index to all other information 

published on this insect. 

Images of Camphor Scale

(continued)

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Camphor Scale
116 Forest Pest Insects in North America:

Shiao, S.N. 1977. Bionomics of the camellia scale, Pseudaonidia duplex

(Cockerell), in northern parts of Taiwan. I. Life history and mortality 

factors. Plant Protection Bulletin, Taiwan 19(2): 65-77.

Shiao, S.N. 1978. Bionomics of the camellia scale, Pseudaonidia duplex

(Cockerell) (Homoptera: Diaspididae) in northern parts of Taiwan. II. 

Natural enemies. Plant Protection Bulletin, Taiwan 20(3): 210-223.

Articles on Camphor Scale
A Photographic Guide 117

39. Coconut Scale, Aspidiotus destructor Signoret (Hemiptera: Diaspididae)

Coconut scale, Aspidiotus destructor Signoret, has an extremely broad 

host range, feeding on over 60 different families of plants. As a pest of 

coconut (Cocos nucifera L.), it normally feeds on the undersurfaces of 

fronds, but when infestations are very dense, even fruits may be infested. 

Palms may be killed by heavy infestations, but in most cases, predators 

suppress the scale to less destructive levels. 

Coconut scale is a common pest of coconut (C. nucifera) and banana 

(Musa), and also infests avocado (Persea americana Miller), bird of 

paradise (Strelitzia), breadfruit (Artocarpus altilis [Parkinson] Fosberg), 

cassava (Manihot esculenta Crantz), cotton (Gossypium), ginger 

(Zingiber officinale Roscoe), guava (Psidium), mango (Mangifera indica

L.), mock orange (Philadelphus), mountain apple (Syzygium malaccense

[L.] Merr. and L.M. Perry), oil palm (Elaeis), papaya (Carica papaya

L.), pandanus (Pandanus), frangiapani (Plumeria), rubber trees (Hevea 

brasiliensis Müll. Arg.), sugarcane (Saccharum), and tea (Camellia 

sinensis [L.] Kuntze).

At a world level, this scale is widely distributed in tropical areas, 

including Puerto Rico. The mainland United States distribution of this 

scale includes Florida, Georgia, North Carolina, and Virginia.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of Coconut Scale

Figure 1. Several adults of coconut 

scale, Aspidiotus destructor, 

on a palm frond. (United States 

National Collection of Scale Insects 

Photographs Archive, USDA 

Agricultural Research Service, 

Bugwood.org)

Figure 2. Crawlers of coconut scale 

interspersed among large adults. 

(United States National Collection of 

Scale Insects Photographs Archive, 

USDA Agricultural Research Service, 

Bugwood.org)
118 Forest Pest Insects in North America:

Images of Coconut Scale

(continued)

Figure 3. Colonies of various density of coconut scale on palm fronds. 

(Both photos: United States National Collection of Scale Insects Photographs 

Archive, USDA Agricultural Research Service, Bugwood.org)

Figure 4. Discolored streaks 

in palm fronds are a sign 

of coconut scale damage. 

(United States National 

Collection of Scale Insects 

Photographs Archive, USDA 

Agricultural Research 

Service, Bugwood.org)
A Photographic Guide 119

Figure 5. Coconuts heavily 

infested with coconut scale. 

(Infonet B. Loehr)

Figure 6. Encarsia citrina

is a polyphagous aphelinid 

that attacks many diaspidid 

scales, including coconut 

scale. (Kristopher Abell, 

University of Massachusetts, 

Bugwood.org) 

A great many natural enemies of coconut scale have been reported (see 

summary in Waterhouse and Norris, 1987). See also discussion in Frank 

and Foltz (1996) for specific natural enemies present in Florida and 

Puerto Rico (see articles below for URL). Among the most important of 

these are the ladybird beetle Cryptognatha nodiceps Marshall and the 

parasitoid Encarsia citrina (Crawford). 

http://www.spc.int/pps/pest_of_the_month_-_january_2005.htm; 

discusses biology and control of coconut scale with reference to islands 

of the Pacific.

http://www.extento.hawaii.edu/kbase/crop/type/a_destru.htm; fact sheet 

from the Hawaiian Extension Service.

http://www.ctahr.hawaii.edu/adap/Publications/ADAP_pubs/2000-5.pdf; 

fact sheet of ADAP (Agricultural Development in American Pacific).

http://www.fs.fed.us/foresthealth/technology/pdfs/FHTET_96_20.PDF; 

Frank and Foltz (1996); FHTET Bulletin of USDA Forest Service, see 

page 13. 

http://www.sel.barc.usda.gov/catalogs/diaspidi/Aspidiotusdestructor.htm; 

ScaleNet catalog, giving a complete list of all recorded natural enemies, 

hosts, and distribution records, and an index to all other information 

published on this insect (over 470 references). 

Waterhouse, D.F. and K.R. Norris. 1987. Biological Control: Pacific 

Prospects. ACIAR, Inkata Press, Melbourne, Australia: 62-71.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Coconut Scale

Article

Images of Coconut Scale

(continued)
120 Forest Pest Insects in North America:

40. Florida Red Scale, Chrysomphalus aonidum (L.) (Hemiptera: 

Diaspididae)

Florida red scale, Chrysomphalus aonidum (L.), is an Asian scale 

invasive in the United States. It is one of the most polyphagous insects 

known, recorded from 70 families of plants. It is most often reported on 

agricultural or ornamental plants but occurs in natural vegetation as well. 

The scale feeds on foliage, producing yellow areas. Heavy infestations 

may cause foliage to drop. 

Citrus (Citrus), holly (Ilex), and palms are the more commonly affected 

groups of plants. 

The U.S. distribution of this scale is from North Carolina, south and west 

to Texas, as well as Hawaii. It is common in greenhouses throughout the 

country. It is also common in most tropical and subtropical parts of the 

world, including Puerto Rico. 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Figure 1. Florida red scale, Chrysomphalus aonidum, on dragontree (Dracaena 

marginata Lam.) (left) and on citrus leaf (right). (Left: United States National 

Collection of Scale Insects Photographs Archive, USDA Agricultural Research 

Service, Bugwood.org; right: Pedro Torrent Chocarro, Bugwood.org) 

Figure 2. Florida red scale 

on an orange. (Pedro Torrent 

Chocarro, Bugwood.org)

Images of 

Florida Red Scale
A Photographic Guide 121

This scale has been the focus of parasitoid introductions in Texas and 

Florida. The aphelinid Aphytis holoxanthus DeBach from Israel has 

provided substantial control in both locations. 

http://www.biosecurity.govt.nz/pests-diseases/plants/florida-red-scale/frsreport.htm; a New Zealand fact sheet.

http://www.sel.barc.usda.gov/catalogs/diaspidi/Chrysomphalusaonidum.

htm; ScaleNet catalog, giving a complete list of all recorded natural 

enemies, hosts, and distribution records, and an index to all other 

information published on this insect.

Clancy, D.W., A.G. Selhime, and M.H. Muma. 1963. Establishment of 

Aphytis holoxanthus as a parasite of Florida red scale in Florida. Journal 

of Economic Entomology 56: 603-605.

Steinberg, S., H. Podoler, and D. Rosen. 1986. Biological control of the 

Florida red scale, Chrysomphalus aonidum, in Israel by two parasite 

species: Current status in the coastal plain. Phytoparasitica 14: 199-204. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Florida Red Scale

Articles
122 Forest Pest Insects in North America:

41. Magnolia White Scale, Pseudaulacaspis cockerelli (Cooley) (Hemiptera: 

Diaspididae)

Magnolia white scale, Pseudaulacaspis cockerelli (Cooley) (known 

formerly as the false oleander scale), is an invasive Asian scale found 

in the southern United States. It is one of the most polyphagous insects 

known, reported from 75 different plant families.

Common host plants include magnolia (Magnolia), bird of paradise 

(Strelitzia), oleander (Nerium oleander L.), azalea (Azalea), plumeria 

(Plumeria), mango (Mangifera indica L.), kukui (Aleurites moluccana

[L.] Willd.), cycads, and palms.

This scale is likely native to southern Asia, but is invasive in many parts 

of the world, including Hawaii and Puerto Rico. In North America, it 

is invasive in the southern United States (Florida to Maryland, west to 

Texas and Kansas). 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of Magnolia 

White Scale

Figure 1. Adults of magnolia white scale, Pseudaulacaspis cockerelli, on areca 

palm (Areca sp.) (left); close up of magnolia white scale adults (right). (Left: 

United States National Collection of Scale Insects Photographs Archive, USDA 

Agricultural Research Service, Bugwood.org; right: Gillian W. Watson, California 

Department of Food & Agriculture)
A Photographic Guide 123

Images of Magnolia 

White Scale (continued)

Figure 2. Parasitoid emergence hole in cover of white magnolia scale. 

(Charles Olsen, USDA APHIS PPQ, Bugwood.org)

Some specialized parasitoids of this scale are known from its native 

south Asian range, but none have been used for biological control of this 

scale in North America. 

http://edis.ifas.ufl.edu/pdffiles/IN/IN30600.pdf; fact sheet of the 

University of Florida. 

http://www.extento.hawaii.edu/kbase/crop/Type/p_cocker.htm; fact sheet 

of the Hawaiian Cooperative Extension Service on biology and control.

http://www.sel.barc.usda.gov/catalogs/diaspidi/

Pseudaulacaspiscockerelli.htm; ScaleNet catalog, giving a complete list 

of all recorded natural enemies, hosts, and distribution records, and an 

index to all other information published on this insect.

Rosen, D. and P. DeBach. 1986. Three new species of Aphytis

(Hymenoptera: Aphelinidae), parasites of Pseudaulacaspis spp. 

(Homoptera: Diaspididae) in India and Australia. Entomophaga 31: 

139-151.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Magnolia White Scale

Articles
124 Forest Pest Insects in North America:

42. White Peach Scale, Pseudaulacaspis pentagona (Targioni-Tozzetti) 

(Hemiptera: Diaspididae) 

Orientation to Pest White peach scale, Pseudaulacaspis pentagona (Targioni-Tozzetti), is an 

invasive scale found in the southeast United States, likely native to Japan 

or China. It has one of the broadest host ranges reported for any insect, 

attacking 85 families of plants, including more than 115 genera in Florida 

alone. The scale has four generations per year in Florida and three in the 

northern parts of its U.S. range. 

A polyphagous species, white peach scale is common on peach (Prunus 

persica [L.] Batsch), mulberry (Morus), persimmon (Diospyros 

virginiana L.), catalpa (Catalpa), hibiscus (Hibiscus), and privet 

(Ligustrum).

In the United States, white peach scale is found from Florida west to 

Texas and north to Maryland and Tennessee. It also occurs in Puerto Rico 

and Hawaii.

Hosts Commonly Attacked

Distribution

Images of White

Peach Scale

Figure 1. Close up of adults of white peach scale, Pseudaulacaspis pentagona. 

(Left: Pennsylvania Department of Conservation and Natural Resources - 

Forestry Archive, Bugwood.org; right: Jeffrey W. Lotz, Florida Department of 

Agriculture and Consumer Services, Bugwood.org)

Figure 2. Adult female of white peach scale with scale cover removed, showing 

eggs. (Lyle Buss, University of Florida, Bugwood.org)
A Photographic Guide 125

Figure 3. Dense bark infestations of white peach scale. (Both photos: 

Eric R. Day, Virginia Polytechnic Institute and State University, Bugwood.org)

Images of White

Peach Scale (continued)

Two species of Encarsia (E. berlesei Howard and E. diaspidicola

Silvestri) are important parasitoids of white peach scale. 

http://entnemdept.ufl.edu/creatures/orn/scales/white_peach_scale.htm; 

fact sheet of the University of Florida.

http://www.sel.barc.usda.gov/catalogs/diaspidi/

Pseudaulacaspispentagona.htm; ScaleNet catalog, giving a complete list 

of all recorded natural enemies, hosts, and distribution records, and an 

index to all other information published on this insect.

Neumann, G., P.A. Follett, R.G. Hollingsworth, and J.H. de León. 

2010. High host specificity in Encarsia diaspidicola (Hymenoptera: 

Aphelinidae), a biological control candidate against the white peach scale 

in Hawaii. Biological Control 54: 107-113.

León, J.H. de, G. Neumann, P.A. Follett, and R.G. Hollingsworth. 

2010. Molecular markers discriminate closely related species Encarsia 

diaspidicola and Encarsia berlesei (Hymenoptera: Aphelinidae): 

biocontrol candidate agents for white peach scale in Hawaii. Journal of 

Economic Entomology 103: 908-916.

Kreiter, P. and A. Panis. 1998. Inventory of the natural enemies of 

the white peach scale Pseudaulacaspis pentagona (Targioni-Tozzetti, 

1886) in the world (Homoptera, Diaspididae). Bulletin de la Société 

Entomologique de France 103: 263-271.

Hanks, L.M. and R.F. Denno. 1993. The white peach scale, 

Pseudaulacaspis pentagona (Targioni-Tozzetti) (Hemiptera: 

Diaspididae): life history in Maryland, host plants, and natural enemies. 

Proceedings of the Entomological Society of Washington 95: 79-88.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on White Peach Scale

Articles
126 Forest Pest Insects in North America:

43. Citrus Whitefly, Dialeurodes citri (Ashmead) (Hemiptera: Aleyrodidae) 

Orientation to Pest Citrus whitefly, Dialeurodes citri (Ashmead), is a polyphagous invasive 

whitefly of Asian origin that was once a major pest of citrus in the United 

States, as well as infesting a range of other plants. Like all whiteflies, this 

species has sessile nymphs that are affixed to plant surfaces, where they 

feed by removing plant sap, debilitating the host. Citrus whitefly secretes 

honeydew, leading to growth of sooty molds on infested plants. 

Citrus whitefly attacks many species, most of which are themselves 

introduced crops or ornamentals. These include citrus (Citrus), allamanda 

(Allamanda), banana shrub (Michelia figo [Lour.] Spreng), cape jasmine 

(Gardenia jasminoides J. Ellis), chinaberry (Melia azedarach L.), laurel 

cherry (Prunus laurocerasus L.), crape myrtle (Lagerstroemia spp.), 

Ficus macrophylla Desf. ex Pers., gardenia (Gardenia jasminoides J. 

Ellis), myrtle (Myrtus spp.), mock olive (Notelaea), and pear (Pyrus). 

Among the native North American plants attached are osage orange 

(Maclura pomifera [Raf.] Schneid.), water oak (Quercus nigra L.), 

persimmon (Diospyros), and green ash (Fraxinus pennsylvanica

Marshall).

In North America, citrus whitefly is found in the southeastern United 

States, from Florida west to Texas and north to Virginia, and also in 

California. 

Hosts Commonly Attacked

Distribution

Images of Citrus Whitefly

Figure 1. Adults of citrus whitefly, Dialeurodes citri. (Both photos: Lyle Buss, 

University of Florida, Bugwood.org)

Figure 2. Nymph of citrus 

whitefly. (Florida Division of 

Plant Industry Archive, Florida 

Department of Agriculture 

and Consumer Services, 

Bugwood.org)
A Photographic Guide 127

Figure 3. Cast skin (top) of citrus whitefly. (Florida Division of Plant Industry 

Archive, Florida Department of Agriculture and Consumer Services, 

Bugwood.org)

Figure 4. Leaf infested with citrus whitefly (white dots dispersed over leaf). 

(Jeffrey W. Lotz, Florida Department of Agriculture and Consumer Services, 

Bugwood.org)

Images of Citrus Whitefly

(continued)
128 Forest Pest Insects in North America:

Figure 5. Sooty mold 

growing on honeydew 

produced by citrus 

whitefly. (INRA: 

Alain Fraval)

Figure 6. The aphelinid 

parasitoid Encarsia 

lahorensis, the 

key natural enemy 

of citrus whitefly. 

(Jeffrey W. Lotz, 

Florida Department 

of Agriculture and 

Consumer Services, 

Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

This invasive whitefly has come under virtually complete biological 

control, at least on citrus, due the influence of the introduced parasitoid 

Encarsia lahorensis Howard.

Images of Citrus Whitefly

(continued)
A Photographic Guide 129

http://entnemdept.ufl.edu/creatures/citrus/citrus_whitefly.htm; a 

University of Florida fact sheet on biology, hosts, distribution and 

control of citrus whitefly.

http://edis.ifas.ufl.edu/pdffiles/IN/IN42700.pdf; a fact sheet of the 

University of Florida, discussing the biology and life history of the 

parasitoid Encarsia lahorensis.

Bellows, T.S. and C. Meisenbacher. 2007. Field population biology of 

citrus whitefly, Dialeurodes citri (Ashmead) (Heteroptera: Aleyrodidae), 

on oranges in California. Population Ecology 49: 127-134.

Web Links for Information 

on Citrus Whitefly

Articles
130 Forest Pest Insects in North America:

44. The Mealybug Oracella acuta (Lobdell) (Hemiptera: Pseudococcidae) 

The mealybug Oracella acuta (Lobdell) is native to the southeastern 

United States. It has up to five generations per year in the southern part 

of the range. First generation crawlers are the mobile dispersal stage. 

Once female crawlers finish dispersing, they either settle on the shoot 

or occasionally between the needles near the fascicle. Females secrete 

a characteristic white resin cell that covers their body. The tips of new 

shoots are the preferred settling site, though the entire shoot may be 

colonized when populations are high. The resin cells, shoots, and needles 

may become covered with black, sooty mold growing on honeydew 

produced by the mealybug. Males develop on the shoot within a covering 

called a test. First generation males are apterous, with subsequent 

generation males being alate. Infestations rarely cause tree mortality, 

but they may severely retard growth. Oracella acuta is a secondary pest, 

usually becoming a problem following insecticide applications targeting 

other insects. 

Hosts of this mealybug include loblolly (Pinus taeda L.), slash (P. 

elliottii Engelm.), Virginia (P. virginiana Miller), shortleaf (P. echinata

Miller), and longleaf (P. palustris Miller) pine.

In North America, this mealybug occurs from Florida north to Virginia 

and west to Texas. It is also invasive in China, where it has become a 

major pest in slash pine plantations.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Figure 1. A colony of the 

mealybug Oracella acuta

on slash pine. (William 

M. Ciesla, Forest Health 

Management International, 

Bugwood.org) 

Images of the Mealybug

Oracella acuta
A Photographic Guide 131

Images of the Mealybug

Oracella acuta (continued)

Figure 2. Close up of 

the mealybug Oracella 

acuta, showing an 

adult female and her 

eggs. (Steve Clarke, 

USDA Forest Service, 

Bugwood.org)

Figure 3. A resin cell, 

formed by feeding of 

the mealybug Oracella 

acuta. (Steve Clarke, 

USDA Forest Service, 

Bugwood.org)
132 Forest Pest Insects in North America:

Important Biological Control 

Agents Related to this 

Pest Species

Three native parasitoids, Zarhopalus debarri Sun, Acerophagus coccois

E. Smith, and Allotropa oracellae Masner, help regulate this mealybug’s 

population size in the southeast United States. All three parasitoids were 

imported to China and released in heavily infested slash pine plantations, 

but failed to suppress the pest. One hypothesis about this failure is that it 

is due to the lack of mealybugs available as hosts in the summer months 

in China. 

None

Clarke, S.R., G.L. Debar, and C.W. Berisford. 1990. Life history of 

Oracella acuta (Homoptera: Pseudococcidae) in loblolly pine seed 

orchards in Georgia. Environmental Entomology 19: 99-103.

Sun, J.-H., S.R. Clarke, G.L. Debarr, and C.W. Berisford. 2004. 

Parasitoid complex of the mealybug Oracella acuta (Lobdell) 

(Hemiptera: Pseudococcidae) in Georgia, USA. Journal Entomological 

Science 39(1): 11-22. (Available at http://www.srs.fs.usda.gov/pubs/ja/

ja_sun005.pdf).

Clarke, S.R., H.-B. Yu, M.-R. Chen, G.L. Debarr, and J.-H. Sun. 2010. 

Classical biological control program for the mealybug Oracella acuta

in Guangdong Province, China. Insect Science 17: 129-139. (Available 

at http://onlinelibrary.wiley.com/doi/10.1111/j.1744-7917.2009.01292.

x/pdf).

Web Links for Information 

on the Mealybug 

Oracella acuta

Articles
A Photographic Guide 133

45. Cottonwood Leaf Beetle, Chrysomela scripta Fabricius (Coleoptera: 

Chrysomelidae)

Cottonwood leaf beetle, Chrysomela scripta Fabricius, is a native insect 

in North America that feeds on various species of poplar (Populus), 

willow (Salix), and alder (Alnus) and is found throughout the United 

States. Adults and larvae feed on leaves, and the yellow eggs are 

laid in clusters on foliage. Young larvae feed in groups and are leaf 

skeletonizers. Young larvae emit chemical exudates for defense against 

predators. Older larvae and adults feed individually. Pupation is on 

the host plant or nearby materials. Adults overwinter under bark, litter 

or forest debris, and there are several generations per year (3-4 in the 

midwestern United States and up to 6-8 in the southern United States). 

Feeding results in reduced growth and multi-forked tops. Damage is of 

greatest concern in cottonwood or willow plantations. 

Various species of poplar (Populus) and occasionally willow (Salix) are 

attacked by this beetle.

Cottonwood leaf beetle is found throughout the United States.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of Cottonwood

Leaf Beetle

Figure 1. Adults (left) of the cottonwood leaf beetle, Chrysomela scripta, on 

leaf, and close up of adult beetle (right). (Left: Andrew J. Boone, South Carolina 

Forestry Commission, Bugwood.org; right: Gerald J. Lenhard, Louiana State 

University, Bugwood.org)

Figure 2. An egg mass (yellow) of cottonwood leaf beetle on leaf (left); a close 

view of an egg mass (right). (Left: James Solomon, USDA Forest Service, 

Bugwood.org; right: Lacy L. Hyche, Auburn University, Bugwood.org)
134 Forest Pest Insects in North America:

Figure 3. A group of cottonwood leaf beetle larvae feeding on leaf (left); a 

close view of a single larva (right). (Left: Lacy L. Hyche, Auburn University, 

Bugwood.org; right: Gerald J. Lenhard, Louisiana State University, Bugwood.org)

Figure 4. Dorsal view 

of pupa of cottonwood 

leaf beetle. (Gerald J. 

Lenhard, Louiana State 

University, Bugwood.org)

Figure 5. Damage to eastern cottonwood terminal from cottonwood leaf beetle 

(left); and close up of damage to leaf from group of feeding larvae (right). (Left: 

James Solomon, U.S. Forest Service, Bugwood.org; right: Lacy L. Hyche, Auburn 

University, Bugwood.org)

Figure 6. Eggs of 

cottonwood leaf beetle 

are preyed on by many 

generalist predators; 

here, by the ladybird 

beetle Neoharmonia 

venusta (Melsheimer). 

(James Solomon, 

U.S. Forest Service, 

Bugwood.org)

Images of Cottonwood

Leaf Beetle (continued)
A Photographic Guide 135

Natural enemies of this beetle include the microsporidian Nosema scripta

Bauer and Pankratz, the ladybird beetle Coleomegilla maculata (De 

Geer), and the pteromalid parasitoid Shizonotus latus (Wlk.). 

http://wiki.bugwood.org/Archive:South/Chrysomela_scripta; article in 

Bugwood Wiki.

http://www.ento.okstate.edu/ddd/insects/leafbeetle.htm; a fact sheet of 

Oklahoma State University compares willow leaf beetle, Chrysomela 

knabi with cottonwood leaf beetle, Chrysomela scripta.

http://aces.nmsuledu/pubs/_circulars/circ552.html; provides information 

on control.

Bauer, L.S. and H.S. Pankratz. 1993. Nosema scripta n. sp. 

(Microsporida: Nosematidae), a microsporidian parasite of 

the cottonwood leaf beetle, Chrysomela scripta (Coleoptera: 

Chrysomelidae). Journal of Eukaryotic Microbiology 40(2): 135-141.

Andersen, D.C. and S.M. Nelson. 2002. Effects of cottonwood leaf 

beetle, Chrysomela scripta (Coleoptera: Chrysomelidae), on survival 

and growth of Fremont cottonwood (Populus fremontii) in northwest 

Colorado. American Midland Naturalist 147: 189-203.

Tenczar, E.G. and V.A. Krischik. 2006. Management of cottonwood 

leaf beetle (Coleoptera: Chrysomelidae) with a novel transplant soak 

and biorational insecticides to conserve coccinellid beetles. Journal of 

Economic Entomology 99: 102-108.

Coyle, D.R., E.R. Hart, J.D. McMillin, L.C. Rule, and R.B. Hall. 2008. 

Effects of repeated cottonwood leaf beetle defoliation on Populus growth 

and economic value over an 8-year harvest rotation. Forest Ecology and 

Management 255(8/9): 3365-3373.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Cottonwood Leaf Beetle

Articles
136 Forest Pest Insects in North America:

46. Imported Willow Leaf Beetle, Plagiodera versicolora (Laicharting) 

(Coleoptera: Chrysomelidae)

Imported willow leaf beetle, Plagiodera versicolora (Laicharting), is an 

introduced insect in North America of European or Asian origin. Adults 

overwinter in protected locations near host trees. Adults begin feeding 

in early spring at leaf expansion and lay clusters of oval yellow eggs 

on leaves. Both larvae and adults are foliage feeders, skeletonizing and 

causing shot hole damage, respectively, to the leaves of willows and 

poplars in both landscape plantings and natural habitats. There are two 

(northern climates) to four (southern climates) generations per year.

Hosts of imported willow leaf beetle include various species of poplar 

(Populus) and willow (Salix). 

This insect is found in North America (throughout the eastern United 

States and southern Canada, and in parts of Alaska), Central Europe, 

Japan, and China. The exact native range is not known. 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of Imported

Willow Leaf Beetle

Figure 1. Adult of imported willow leaf beetle, Plagiodera versicolora. (Jim Baker, 

North Carolina State University, Bugwood.org)

Figure 2. Shot-hole type feeding damage caused by adults of imported willow 

leaf beetle. (Lacy L. Hyche, Auburn University, Bugwood.org)
A Photographic Guide 137

Figure 3. Larvae and feeding damage of imported willow leaf beetle. (Paul 

Weston, Cornell University, Bugwood.org)

Figure 4. Clump of willow showing branches defoliated by imported willow leaf 

beetle. (U.S. Forest Service - Ogden Archive, USDA Forest Service, 

Bugwood.org)

Figure 5. The coccinellid Neoharmonia venusta, a predator of imported willow 

leaf beetle eggs. (James Solomon, USDA Forest Service, Bugwood.org)

Images of Imported

Willow Leaf Beetle

(continued)
138 Forest Pest Insects in North America:

Important Biological Control 

Agents Related to this 

Pest Species

In North America, the chalcids Schizonotus rotundivenris (Girault) and 

Schizonotus latus (Walker) parasitize the imported willow leaf beetle. 

Eggs are eaten by predators, especially the coccinellid Neoharmonia 

venusta (Melsheimer).

http://wiki.bugwood.org/Archive:Poplar/Plagiodera_versicolora

Wade, M.J. and F. Breden. 1986. Life history of natural populations of 

the imported willow leaf beetle, Plagiodera versicolora (Coleoptera: 

Chrysomelidae). Annals of the Entomological Society of America

79: 73-79.

Web Links for Information on 

Imported Willow Leaf Beetle

Articles
A Photographic Guide 139

47. Elm Leaf Beetle, Xanthogaleruca luteola (Müller) (Coleoptera: 

Chrysomelidae)

Orientation to Pest Elm leaf beetle, Xanthogaleruca luteola (Müller), is an introduced 

insect in North America of European or Asian origin that feeds on elms 

(Ulmus). It overwinters as an adult in protected locations. Eggs are laid 

in clusters on elm leaves and larvae feed as leaf skeletonizers, while 

adults produce shot-hole damage to leaves. Eggs are pointed, rather 

than oval in outline. Pupation occurs at the base of infested trees. Two 

generations may occur per year. 

This beetle feeds on various imported or native elms (Ulmus), and is 

important as a pest of American elm (Ulmus americana L.). 

This invasive insect is found throughout the United States and southern 

Canada, wherever elms occur naturally or have been planted as 

ornamentals. 

Hosts Commonly Attacked

Distribution

Images of 

Elm Leaf Beetle

Figure 1. Adults of elm leaf beetle, Xanthogaleruca luteola. (Both photos: 

Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org)

Figure 2. Cluster of elm leaf beetle eggs. (Gyorgy Csoka, Hungary Forest 

Research Institute, Bugwood.org)
140 Forest Pest Insects in North America:

Figure 3. Larvae of elm leaf beetle (young larvae, top; older larvae, middle; 

close up of mature larva, bottom). (Top: Lacy L. Hyche, Auburn University, 

Bugwood.org; middle, bottom: Gyorgy Csoka, Hungary Forest Research Institute, 

Bugwood.org)

Images of Elm Leaf 

Beetle (continued)
A Photographic Guide 141

Images of Elm Leaf 

Beetle (continued)

Figure 4. Pupae of elm leaf beetle. (Whitney Cranshaw, Colorado State 

University, Bugwood.org)

Figure 5. Elm leaves (top) skeletonized by elm leaf beetle larvae, and with shothole damage from adult feeding (below). (Top: James Solomon, USDA Forest 

Service, Bugwood.org; bottom: Pennsylvania Department of Conservation and 

Natural Resources - Forestry Archive, Bugwood.org)
142 Forest Pest Insects in North America:

Images of Elm Leaf 

Beetle (continued)

Figure 6. Oomyzus gallerucae is an important egg parasitoid affecting elm leaf 

beetle populations in some parts of the United States. (Bruno Lavoue)

Figure 7. The tachinid Erynniopsis antennata is an introduced larval parasitoid 

of elm leaf beetle. (Jack Kelly Clark, University of California - Statewide IPM 

Program, Bugwood.org)

Oomyzus gallerucae (Fonscolombe) (=Tetrastichus gallerucae [Boy]) 

is an introduced egg parasitoid of elm leaf beetle that is found in 

Missouri, where it is of major importance, and in California. The tachinid 

Erynniopsis antennata (Rondani) is an introduced larval parasitoid 

of elm leaf beetle that is established in California and of moderate 

importance there. 

Important Biological Control 

Agents Related to this 

Pest Species
A Photographic Guide 143

http://californiaagriculture.ucanr.org/landingpage.cfm?article=ca.

v052n02p18&fulltext=yes; an IPM plan for control of elm leaf beetle or 

street trees in California.

http://www.ext.colostate.edu/pubs/insect/05521.html; fact sheet from 

Colorado State University Extension.

http://extension.missouri.edu/publications/DisplayPub.aspx?P=g7356; 

fact sheet from University of Missouri Extension.

http://www.hgic.umd.edu/_media/documents/hg113_000.pdf; fact sheet 

from Maryland Cooperative Extension Service.

Dreistadt, S.H. and D.L. Dahlsten. 1990. Distribution and abundance of 

Erynniopsis antennata (Dipt.: Tachinidae) and Tetrastichus brevistigma

(Hym.: Eulophidae), two introduced elm leaf beetle parasitoids in 

northern California. BioControl 35: 527-536.

Dreistadt, S.H. and D.L. Dahlsten. 1991. Establishment and 

overwintering of Tetrastichus gallerucae (Hymenoptera: Eulophidae), 

an egg parasitoid of the elm leaf beetle (Coleoptera: Chrysomelidae) in 

northern California. Environmental Entomology 20: 1711-1719.

Meiners, T. and M. Hilker. 1997. Host location in Oomyzus gallerucae

(Hymenoptera: Eulophidae), an egg parasitoid of the elm leaf beetle 

Xanthogaleruca luteola (Coleoptera: Chrysomelidae). Oecologia 112: 

87-93.

Puttler, B. and W.C. Bailey. 2003. Establishment of Oomyzus gallerucae

(Hymenoptera: Eulophidae), an egg parasite of the elm leaf beetle 

(Coleoptera: Chrysomelidae), in Missouri and adjacent states. Biological 

Control 27: 20-24.

Web Links for Information 

on Elm Leaf Beetle

Articles
144 Forest Pest Insects in North America:

48. Larger Elm Leaf Beetle, Monocesta coryli (Say) (Coleoptera: 

Chrysomelidae)

Orientation to Pest The larger elm leaf beetle, Monocesta coryli (Say), is a native insect in 

the United States that is of concern in Florida as an occasional pest of 

elms (Ulmus). It has a similar biology to the invasive elm leaf beetle, 

Xanthogaleruca luteola (Müller), but is not as damaging, in part because 

it has only one generation per year. Young larvae feed in groups on elm 

leaves but older larvae disperse and feed singly. Larval feeding causes 

leaves to become skeletonized, giving trees a brown or defoliated look. 

Mature larvae leave trees to pupate in the soil. 

The larger elm leaf beetle feeds on various elms (Ulmus). 

This beetle occurs spottily from Florida to Pennsylvania, and west to 

Ohio and Kansas.

Hosts Commonly Attacked

Distribution

Figure 1. Views of the adult larger elm beetle, Monocesta coryli. (Both photos: 

Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org)

Images of Large

Elm Leaf Beetle

Figure 2. Female of larger elm 

leaf beetle with egg mass. 

(North Carolina Forest Service 

Archive, Bugwood.org)
A Photographic Guide 145

Images of Large

Elm Leaf Beetle (continued)

Figure 3. Young larvae of larger elm leaf beetle (left) feed in groups; close up 

of one larva (right). (Both photos: Gerald J. Lenhard, Louiana State University, 

Bugwood.org)

Figure 4. Defoliated elms fed on by larger elm leaf beetle. (Both photos: Jim 

Baker, North Carolina State University, Bugwood.org)
146 Forest Pest Insects in North America:

No natural enemies of this species have been well documented, but the 

tachinid Icelia triquetra (Olivier) is reported to attack this species. 

http://entnemdept.ufl.edu/creatures/trees/le_leaf_beetle.htm; fact sheet of 

the University of Florida.

Anderson, D. and C.S. Papp. 1961. The larger elm leaf beetle, Monocesta 

coryli (Say). Proceedings of the Entomological Society of Washington

63: 203-207.

Kelsheimer, E.G. 1945. Notes on the great elm leaf beetle. Florida 

Entomologist 28: 25-27.

Kelsheimer, E.G. 1957. Larger elm leaf beetle (Monocesta coryli). 

Cooperative Economic Insect Report, Plant Pest Control Division, 

Agricultural Research Service, U.S. Department of Agriculture 7: 650. 

Madden, A.H. 1940. Larger elm leaf beetle (Monocesta coryli Say). 

Insect Pest Survey Bulletin, Bureau of Entomology and Plant Quarantine, 

U.S. Department of Agriculture 20: 408. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Larger Elm Leaf Beetle

Articles
A Photographic Guide 147

49. Giant Palm Weevil, Rhynchophorus cruentatus (F.) (Coleoptera: 

Curculionidae)

Orientation to Pest Giant palm weevil (also called palmetto weevil), Rhynchophorus 

cruentatus (F.), is native to the West Indies, South America, and 

coastal areas of the southern United States. This species attacks various 

introduced and native palms. The adult is variable in color pattern. Adults 

emit aggregation pheromones to concentrate attack on stressed trees. 

Eggs are laid in the bases of leaves or in wounds in a dying palm. Larvae 

feed primarily in the soft tissue surrounding the apical meristem. Mature 

grubs migrate to the periphery of the stem or petioles and prepare a 

cocoon from palm fibers. The weevil attacks lightning-struck or stressed 

palms, such as ones that have recently been transplanted. Healthy palms 

in natural settings are rarely damaged.

The giant palm weevil is closely associated with cabbage palmetto (Sabal 

palmetto [Walker] Loddiges ex J.A. et Schultes), which is native to the 

southeastern United States. The native saw palmetto (Serrenoa repens

[Bart.] Small) is an alternate host. Infestations have also been found in 

several introduced palms such as the Canary Island date palm (Phoenix 

canariensis Hortorum ex Chabaud), Phoenix dactylifera L., Pritchardia

sp., Washingtonia sp., royal palms (Roystonea sp.), Latania sp., coconut 

palm (Cocos nucifera L.), and Caryota sp. 

This weevil is found in the United States in areas where palms grow, 

from Florida to Texas and north along the coast to South Carolina. 

Hosts Commonly Attacked

Distribution

Images of 

Giant Palm Weevil

Figure 1. Adult of giant palm weevil (also called palmetto weevil), Rynchophorus 

cruentatus. The adult is variable in color (right). (Left: Jim Occi, BugPics, 

Bugwood.org; right: Doug Caldwell, University of Florida, Bugwood.org)
148 Forest Pest Insects in North America:

Images of Giant

Palm Weevil (continued)

Figure 2. Larvae of giant palm weevil in Bismark palm (Bismarckia nobilis

Hildebrandt and H.Wendl.). (Left: Wikipedia Commons; right: Lyle Buss, 

University of Florida, Bugwood.org)

Figure 3. Cocoon of giant palm weevil, inside of which the larva pupates. 

(Lyle Buss, University of Florida, Bugwood.org)

Figure 4. Left: Sabal palm (Sabal sp.) 

killed by giant palm weevil; bottom: 

Canary island date palm, Phoenix 

canariensis, killed by giant palm weevil. 

(Both photos: Robin M. Giblin-Davis)
A Photographic Guide 149

Important Biological Control 

Agents Related to this 

Pest Species

Natural enemies of this species are not reported from North America but 

some have been noted in other parts of its range. However, since this 

weevil is a native species in the United States and since damage occurs 

principally in planted palms in landscapes, the use of pesticides is likely 

to be an adequate and more efficient method of control.

http://entnemdept.ufl.edu/creatures/orn/palmetto_weevil.htm; fact sheet 

of the University of Florida.

http://www.doacs.state.fl.us/pi/pest_alerts/pdf/giantpalmweevils.pdf; 

fact sheet “Giant palm weevils of the genus Rhynchophorus (Coleoptera: 

Curculionidae) and their threat to Florida palms”; FDACS-Division of 

Plant Industry, March 2010.

Giblin-Davis, R.M. and F.W. Howard. 1989. Vulnerability of stressed 

palms to attack by Rhynchophorus cruentatus (Fabricius) (Coleoptera: 

Curculionidae) and insecticidal control of the pest. Journal of Economic 

Entomology 82: 1185-1190. 

Giblin-Davis, R.M., A.C. Oehschlager, A. Perez, G. Gries, R. Gries, 

T.J.Weissling, C.M. Chinchilla, J.E. Peña, R.H. Hallett, and H.D. Pierce, 

Jr. 1996. Chemical and behavioral ecology of palm weevils. Florida 

Entomologist 79: 153-167. (Available at http://www.fcla.edu/FlaEnt/

fe79p153.pdf)

Web Links for Information 

on Giant Palm Weevil

Articles
150 Forest Pest Insects in North America:

50. Red Palm Weevil, Rhynchophorus ferrugineus (Olivier) (Coleoptera: 

Dryophthoridae)

Orientation to Pest The red palm weevil, Rhynchophorus ferrugineus (Olivier), is native 

to south Asia and Melanesia, where it is a serious pest of palms. Since 

the 1980s, this weevil has spread rapidly throughout many other parts 

of the world, reaching the United States (southern California) in 2010. 

The adult is 2-5 cm long and usually rusty red, but color variants 

are common. Larvae feed by tunneling in the trunks of palm trees, 

weakening and eventually killing trees. Red palm weevil is a major 

pest of date palms (Phoenix dactylifera L.) and coconut palms (Cocos 

nucifera L.). Palms damaged by red palm weevil show (1) foliage 

injuries that include straight edges instead of pointed tips, notching of 

lateral pinnae, and sometimes a linear series of “windows” across pinnae, 

(2) tunnels in the trunk or at the base of fronds, (3) oozing of viscous 

fluids from tunnels; (4) frass at entrance of feeding tunnels, (5) empty 

pupal cases and the bodies of dead adults around heavily infested palms, 

and (6) breaking of the trunk, or toppling of the palm crown. This weevil 

is a pest of both cultivation (agricultural or landscaping palms) and 

native palms in wildlands. 

The red palm weevil is especially damaging economically to date 

palms (P. dactylifera) and coconut palms (C. nucifera). Other hosts 

that have been recorded include palms in the genera Areca, Arenga, 

Borassus, Caryota, Corypha, Livistona, Metroxylon, Oreodoxa, Sabal, 

Trachycarpus, and Washingtonia. Of potential concern in the United 

States is the risk to native palms in the genera Washingtonia and Sabal. 

Red palm weevil is from south Asia and Melanesia, but since the 1980s, 

it has spread to Africa, Mediterranean Europe, the Caribbean, and 

southern California (USA). 

Hosts Commonly Attacked

Distribution

Images of Red 

Palm Weevil

Figure 1. Adult red palm weevil (dark form found in California), Rhynchophorus 

ferrugineus. (John Kabashima, UC Cooperative Extension, Bugwood.org)
A Photographic Guide 151

Images of Red 

Palm Weevil (continued)

Figure 2. Larva and pupa of red palm weevil (red form of adult, from France). 

(Christina Hoddle, University of California - Riverside, Bugwood.org)

Figure 3. Red palm weevil larva in open pupal cell. (Mike Lewis, Center for 

Invasive Species Research, Bugwood.org)
152 Forest Pest Insects in North America:

Images of Red 

Palm Weevil (continued)

Figure 4. Palm frond with typical damage from red palm weevil. (Mike Lewis, 

Center for Invasive Species Research, Bugwood.org)

Figure 5. Landscape palm damaged by invasive red palm weevils. 

(Christina Hoddle, University of California - Riverside, Bugwood.org)
A Photographic Guide 153

Images of Red 

Palm Weevil (continued)

Figure 6. Native 

California fan palms, 

Washingtonia filifera

(Lindl.) H.Wendl., at 

Mountain Palm Springs 

in Anza Borrego State 

Park in southern 

California may be hosts 

for red palm weevil. 

(Bill Sullivan for 

ABDNHA, Bugwood.org)

Biological control of the red palm weevil has so far been focused on 

control methods that can be applied to agricultural palm plantations or 

landscape palms in urban areas. Should native palms in wildlands be 

affected, classical biological control (based on importation of parasitoids 

of the weevil from its native range) should be investigated.

http://www.palms.org/palmsjournal/2002/redweevil.htm; a fact sheet 

about this pest in the Mediterranean region.

http://cisr.ucr.edu/red_palm_weevil.html; University of California fact 

sheet with photos of red palm weevil and its damage.

http://www.cdfa.ca.gov/phpps/rpw/index.html; California Department of 

Agriculture site with photos of pest.

Murphy, S.T. and B.R. Briscoe. 1999. The red palm weevil as an alien 

invasive: biology and the prospects for biological control as a component 

of IPM. Biocontrol News and Information 20(1): 35N-46N. (Available at 

http://www.iraqi-datepalms.net/uploadedfiles/review%20article.pdf).

Faleiro, J.R. 2006. A review of the issues and management of the red 

palm weevil Rhynchophorus ferrugineus (Coleoptera: Rhynchophoridae) 

in coconut and date palm during the last one hundred years. International 

Journal of Tropical Insect Science 26 (3): 135-154.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Red Palm Weevil

Articles
154 Forest Pest Insects in North America:

51. Pales Weevil, Hylobius pales (Herbst) (Coleoptera: Curculionidae)

Orientation to Pest The pales weevil, Hylobius pales (Herbst), is native to North America, 

where it is the most serious pest of young seedling pines in both cutover 

lands undergoing regeneration and in recently planted plantations or 

Christmas tree plantations where stumps have not been removed. This 

weevil is also the vector of Leptographium procerum, the causal agent of 

Leptographium root disease. The species overwinters as adults beneath 

litter or as larvae in roots. Eggs are laid in the roots of fresh stumps, 

where larvae then create galleries and feed. Pupation occurs in the outer 

sapwood. There is usually one generation per year and adults can live up 

to 2 years. Adult feeding on young seedlings (up to 1 cm in diameter) is 

the most important type of damage because it may cause girdling and tree 

death. Adult feeding can also kill tips of branches. In cut over forest land, 

damage can be lowered by delaying replanting for 1 or 2 years to allow 

adults to emerge from infested stumps and leave the area. In Christmas 

tree plantations, damage can be lowered by delaying replanting of cut 

areas, treating stumps with pesticides to kill adult weevils, or maintaining 

stumps in a living condition to prevent breeding (as in coppice harvesting 

of Christmas trees).

The pales weevil affects all pines (Pinus spp.) native to North America 

and also many exotic pines. It is also found in spruce (Picea spp.), fir 

(Abies spp.), juniper (Juniperus spp.), larch (Larix spp.), hemlock (Tsuga

spp.), northern white cedar (Thuja occidentalis L.), and Douglas fir 

(Pseudotsuga menziesii [Mirbel] Franco).

The pales weevil is found throughout eastern North America, west to the 

Great Plains and north to southern Canada.

Hosts Commonly Attacked

Distribution

Images of 

Pales Weevil

Figure 1. Adult of the pales weevil, Hylobius pales. (Clemson University - USDA 

Cooperative Extension Slide Series, Bugwood.org)
A Photographic Guide 155

Figure 2. Larvae of 

pales weevil, removed 

from galleries. 

(USDA Forest Service 

publication “Weevils”)

Figure 3. Left, pale weevil larvae develop in roots of stumps left after harvest; 

right, bark removed from stump to show the breeding galleries of pales weevil. 

(Left: Eric R. Day, Virginia Polytechnic Institute and State University, 

Bugwood.org; right: Mary Ann Hansen, Virginia Polytechnic Institute and 

State University, Bugwood.org)

Figure 4. Feeding by adult 

pales weevils can girdle 

and kill seedlings (left) or 

branches (right), destroying 

forest regeneration or 

damaging the shape and 

appearance of Christmas 

trees. (Left: USDA Forest 

Service - Northeastern 

Area Archive, USDA Forest 

Service; right: Eric R. Day, 

Virginia Polytechnic Institute 

and State University, 

Bugwood.org)

Images of Pales Weevil

(continued)
156 Forest Pest Insects in North America:

The only known specialized natural enemy of this species is the 

euphorine braconid parasitoid Microctonus pachylobi Muesebeck, which 

develops in the adult weevil. 

http://www.forestpests.org/nursery/weevils.html; fact sheet on weevils of 

forestry importance.

http://wiki.bugwood.org/Hylobius_pales; fact sheet on biology and 

control of pales weevil.

http://pubs.ext.vt.edu/2902/2902-1102/2902-1102.pdf; fact sheet from 

Virginia Tech.

http://www.fl-dof.com/publications/fh_pdfs/pine%20reproductive%20we

evils.pdf; short article on pine reproduction weevils.

Zanzot, J.W., G. Matusick, and L.G. Eckhardt. 2010. Ecology of rootfeeding beetles and their associated fungi on longleaf pine in Georgia. 

Environmental Entomology 39: 415-423.

Nevill, R.J. and S.A. Alexander. 1992. Transmission of Leptographium 

procerum to eastern white pine by Hylobius pales and Pissodes 

nemorensis (Coleoptera; Curculionidae). Plant Disease 76: 307-310.

Dixon, W.N. and J.L. Foltz. 1990. Pine reproduction weevils, Hylobius 

pales (Herbst) and Pachylobius picivorus (Germar) (Coleoptera: 

Curculionidae). Entomology Circular #332, University of Gainesville, 

Florida.

Lynch, A.M. 1984. The pales weevil, Hylobius pales (Herbst): a 

synthesis of the literature. Journal of the Georgia Entomological Society

19 (3, Suppl. 1). 

Corneil, J.A. and L.F. Wilson. 1981. How to identify and control 

pales weevil [Hylobius pales] in Christmas tree plantations. St. Paul, 

Minnesota: North Central Forest Experiment Station, USDA Forest 

Service: 5 p. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Pales Weevil

Articles
A Photographic Guide 157

52. Pine Root Collar Weevil, Hylobius radicis (Buchanan) (Coleoptera: 

Curculionidae)

Orientation to Pest The pine root collar weevil, Hylobius radicis (Buchanan), is native 

to eastern North America, where it is damaging in Scots pine (Pinus 

sylvestris L.) Christmas tree farms and in red pine (Pinus resinosa Sol. ex 

Aiton) plantations, but not natural forests. Eggs are laid in the root collar 

zone of healthy trees. Larval feeding may kill young trees or badly stress 

older trees. That stress can predispose mature trees to lethal attacks by 

bark beetles. This weevil is associated with several fungi linked to red 

pine decline. Damage may be reduced in a young stands before canopy 

closure by pruning away lower branches and removing litter and soil 

around the base of trunks to reduce weevil oviposition. 

The most frequently affected species is Scots pine (P. sylvestris), 

followed by red pine (P. resinosa), when grown in plantation.

The pine root collar weevil is found from Newfoundland in Canada, 

south to Virginia and west to Minnesota and Manitoba.

Hosts Commonly Attacked

Distribution

Images of Pine 

Root Collar Weevil

Figure 1. Adult of the pine root collar weevil, Hylobius radicis. (Jennifer C. Giron 

Duque, University of Puerto Rico, Bugwood.org)
158 Forest Pest Insects in North America:

Images of Pine Root

Collar Weevil (continued)

Figure 2. Larva of pine root collar weevil dissected out of wood. (James B. 

Hanson, USDA Forest Service, Bugwood.org)

Figure 3. Damage of pine root collar weevil in a mixed red and Scots pine stand. 

(Steven Katovich, USDA Forest Service, Bugwood.org)

Very few natural enemies have been recorded attacking pine collar 

weevil, the main ones being the braconids Bracon radicis Shenefelt and 

Miller and Microctonus pachylobi Muesebeck.

http://wiki.bugwood.org/Archive:Northeast/Hylobius_radicis; fact sheet 

from Bugwood Wiki.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information on 

Pine Root Collar Weevil 
A Photographic Guide 159

Articles Wilson, L.F. and I. Millers. 1983. Pine root collar weevil – its ecology 

and management. Technical Bulletin No. 1675, United States Department 

of Agriculture, Washington, DC: 34 p. 

Klepzig, K.D., K.F. Raffa, and E.B. Smalley. 1991. Association of an 

insect-fungal complex with red pine decline in Wisconsin. Forest Science 

37(4): 1119-1139.

Rieske, L.K. and K.F. Raffa. 1993. Potential use of baited pitfall traps in 

monitoring pine root weevil (Hylobius pales, H. radicis, and Pachylobius 

picivorus) populations and infestation levels. Journal of Economic 

Entomology 86: 475-485.
160 Forest Pest Insects in North America:

53. Pitch-eating Weevil, Pachylobius picivorus (Germar) (Coleoptera: 

Curculionidae)

Orientation to Pest The pitch-eating weevil, Pachylobius picivorus (Germar), is native 

pest of pines in the eastern United States that is especially important in 

southern states. This weevil’s biology and damage are very similar to that 

of the pales weevil, Hylobius pales (Herbst). Damage occurs in cut-over 

stands of various kinds of pines, where adults feed either on the inner 

bark of small stems of the remaining trees or on planted or naturally 

regenerated pine seedlings. Seedling death is the most important kind of 

damage. Eggs are laid in green roots of recently cut stumps or those of 

dead or dying trees. Adults dig through soil to reach roots for oviposition. 

Larvae feed in the roots’ cambial layer and eventually pupate there, 

after having constructed a cell of wood chips. Harvest creates abundant 

stumps, allowing population increase of this insect and focusing damage 

on cut-over sites. This weevil is one of several species associated with 

fungi believed to be the cause of decline of red pine (Pinus resinosa Sol. 

ex Aiton).

This weevil feeds on various pines, but especially shortleaf (P. echinata

Mill.), loblolly (P. taeda L.), and slash pines (P. elliottii Engelm.) in 

the southern United States, and Scots pine (P. sylvestris L.), in the 

northeastern/northcentral part of the country. 

The pitch-eating weevil is found throughout the eastern United States, 

but is most common from Virginia to Florida and west to Oklahoma and 

Texas.

Hosts Commonly Attacked

Distribution

Images of 

Pitch-eating Weevil

Figure 1. Pitch-eating weevil, Pachylobius picivorus, on a pine stem (left), the 

adult’s feeding site; and close up (right). (Left: Terry S. Price, Georgia Forestry 

Commission, Bugwood.org; right: Marvin Smith)
A Photographic Guide 161

Images of Pitch-eating 

Weevil (continued)

Figure 2. Feeding on 

pine stem by adults of 

the pitch-eating weevil. 

(Robert L. Anderson, 

USDA Forest Service, 

Bugwood.org)

Figure 3. Larva of pitch-eating weevil, extracted from a root, the larval feeding 

site. (Wayne N. Dixon, Florida Department of Agriculture and Consumer 

Services, Bugwood.org)
162 Forest Pest Insects in North America:

Important Biological Control 

Agents Related to this 

Pest Species

Very few specialized natural enemies have been recorded attacking pitcheating weevil, the main one being Microctonus pachylobi Muesebeck, 

which attacks the adult stage.

http://wiki.bugwood.org/Pachylobius_picivorus; Bugwood Wiki fact 

sheet.

Walker, A.I. 1975. The biology and habits of the pales weevil, Hylobius 

pales (Herbst), and the pitcheating weevil, Pachylobius picivorus

(Germar). Dissertation Abstracts International, B 35(8): 3962.

Dixon, W.N. and J.L. Foltz. 1990. Pine reproduction weevils, Hylobius 

pales (Herbst) and Pachylobius picivorus (Germar) (Coleoptera: 

Curculionidae). Entomology Circular #332, University of Gainesville, 

Florida.

Rieske, L.K. and K.F. Raffa. 1990. Use of a monitoring system to 

evaluate pesticide efficacy and residual activity against two pine 

root weevils, Hylobius pales and Pachylobius picivorus (Coleoptera: 

Curculionidae), in Christmas tree farms. Great Lakes Entomology 23: 

189-193.

Rieske, L.K. and K.F. Raffa. 1991. Effect of varying ethanol and 

turpentine levels on attraction of two pine root weevil species, 

Hylobius pales and Pachylobius picivorus (Coleoptera: Curculionidae). 

Environmental Entomology 20: 48-52.

Web Links for Information 

on Pitch-eating Weevil

Articles
A Photographic Guide 163

54. White Pine Weevil, Pissodes strobi (Peck) (Coleoptera: Curculionidae)

Orientation to Pest White pine weevil, Pissodes strobi (Peck), is native to North America. 

This weevil can breed in a wide range of native and introduced pine and 

spruce species. Eastern populations attack especially eastern white pine 

(Pinus strobus L.) and Norway spruce (Picea abies (L.) H. Karst.). In 

the western United States, Engelmann spruce (P. engelmanni Hopkins) 

and Sitka spruce (P. sitchensis [Bong] Carr.) are attacked. These western 

populations were formerly felt to be separate species and were studied 

under the names Pissodes engelmanni Hopkins and Pissodes sitchensis

Hopkins, respectively. Cross breeding experiments, however, found all 

populations to be inter-fertile and thus these western populations were 

synonymized under the name P. strobi, which is how the name is used 

here. The important damage by this species is caused by larvae, which 

tunnel in and kill leaders, inducing branching and crooked trunks. Adults 

overwinter in the litter and feed on the cambium of the main terminals 

of their hosts. Eggs are laid in these terminals and larvae feed as cambial 

borers, often then girdling and killing the terminal. Larvae pupate in 

chambers made in the woody part of the stem. This species is considered 

the most serious pest of eastern white pine regeneration. Losses can be 

very high (up to 40 percent) to merchantable timber in heavily infested 

stands over the life of a cohort of trees. Attack is recognized by oozing 

of pitch from the terminal, followed by wilting and terminal death (and 

change of color to reddish brown). Signs of former attacks are seen 

in bushy or crooked tree form. Damage to young white pines may be 

partially reduced by maintaining a shady over-story of hardwoods, 

as weevil oviposition is greatest in full sun. Natural enemies are not 

sufficient to prevent significant losses when silvicultural factors present 

are favorable to this insect. 

A variety of native and introduced pines and spruces, especially 

eastern white (Pinus strobus), and jack (P. banksiana Lamb.) pines and 

Norway (Picea abies), white (P. glauca [Moench] Voss), Engelmann 

(P. engelmanni), and Sitka (P. sitchensis) spruce.

The white pine weevil is found widely in both the eastern and western 

United States and Canada, in the ranges of its principal pine and spruce 

hosts.

Hosts Commonly Attacked

Distribution
164 Forest Pest Insects in North America:

Images of White Pine

Weevil

Figure 1. Adult of white pine weevil, Pissodes strobi (left), feeding on terminal; 

close up (right) of adult. (Left: A. Steven Munson, USDA Forest Service, 

Bugwood.org; right: U.S. Department of Agriculture Forest Service) 

Figure 2. Group of white pine weevil larvae feeding in a stem (left), and close up 

(right). (Left: Dave Powell, USDA Forest Service, Bugwood.org; right: Joseph 

O’Brien, USDA Forest Service, Bugwood.org)
A Photographic Guide 165

Figure 3. Leader of spruce (left) killed by white pine weevil; and close up (right) 

of pitch oozing from pine leader fed on by adults of white pine weevil. (Left: Troy 

Kimoto, Canadian Food Inspection Agency, Bugwood.org; right: E. Bradford 

Walker, Vermont Department of Forests, Parks and Recreation, Bugwood.org)

Figure 4. Damage to form of pines from white pine weevil injury. Left, old pine 

with multiple crooked trunks; right, bush-like pines with many leaders. (Left: 

Steven Katovich, USDA Forest Service, Bugwood.org; right: Joseph O’Brien, 

USDA Forest Service, Bugwood.org)

Images of White Pine

Weevil (continued)
166 Forest Pest Insects in North America:

Not surprisingly, given that this native insect has a large geographical 

range and feeds on several tree genera, a variety of parasitoids and 

predators have been found associated with white pine weevil brood, 

including the parasitoids Eurytoma pissodes Girault, Microbracon

(now Bracon) pini Muesebeck, Dolichomitus terrebrans nubilipennis

(Viereck), Coeloides pissodes (Ashmead), and Allodorus crassigaster

(Provancher). The principal predator of importance is Lonchaea corticis

Taylor. See Mills and Fischer (1986) for a summary and discussion 

of white pine weevil natural enemies. However, none of these species 

reduce populations of white pine weevil to non-damaging levels. 

Consequently, the concept of introducing new natural enemies from 

Pissodes species native to Europe was studied (Kennis and Mills, 1994), 

but no species were ever actually introduced.

http://cfs.nrcan.gc.ca/subsite/weevil/home-accueil; fact sheet of Natural 

Resources Canada.

http://www.na.fs.fed.us/spfo/pubs/howtos/ht_white/white.htm; USDA 

Forest Service bulletin on how to manage white pine weevil damage.

http://ir.library.oregonstate.edu/xmlui/handle/1957/11007; thesis 

providing a hazard rating system for white pine weevil risk to Sitka 

spruce in Oregon, USA.

Mills, N.J. and P. Fischer. 1986. The entomophage complex of Pissodes

weevils, with emphasis on the value of P. validirostris as a source of 

parasitoids for use in biological control, pp. 297-307. In: Roques, A. 

(ed.). Proceedings of the 2nd Conference on the Cone and Seed insects 

Working Party, Briancon, France, September 3-5, 1986.

Kenis, M. and N.J. Mills. 1994. Parasitoids of European species of the 

genus Pissodes (Col: Curculionidae) and their potential for the biological 

control of Pissodes strobi (Peck) in Canada. Biological Control 4(1): 

14-21.

Daoust, G. and M.J. Mottet. 2006. Effect of white pine weevil (Pissodes 

strobi Peck) on plantations of Norway spruce (Picea abies [L.] Karst.). 

Part 1: Productivity and quality of stems. Forestry Chronicle 82(4): 

538-549. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on White Pine Weevil

Articles
A Photographic Guide 167

55. Eastern Pine Weevil, Pissodes nemorensis Germar (Coleoptera: 

Curculionidae) 

Eastern pine weevil, Pissodes nemorensis Germar, is now the name that 

is applied to what was formerly known as northern pine weevil (Pissodes 

approximatus Hopkins), which is no longer considered a valid species. 

Eastern pine weevil is native to North America, where it feeds on cedars 

(Cedrus) and pines (Pinus). In the southern United States, adults are 

active in fall, winter and spring, and are inactive in summer. Eggs are 

laid in the spring in stems or branches. The northern form appears to 

commonly breed also in stumps of cut trees and becomes a pest in 

plantations as numbers build up. Larvae feed in the cambium and pupate 

in the wood in cells make of wood chips. Adults feed on branches and 

terminals, which may be killed, leading to bushiness or crooked stems. 

Small trees may be killed by larval feeding. 

In the northern part of its range, eastern pine weevil breeds in pines, 

especially red (Pinus resinosa Sol. ex Aiton) and Scots (P. sylvestris L.) 

pines. In the southern United States, both cedars and pines are attacked. 

Cedars used as hosts include both native species and exotic cedars 

such as deodar cedar (Cedrus deodara [Roxb.] G. Don), Atlas cedar 

(C. atlantica [Endl.] Manetti ex Carrière), and cedar of Lebanon 

(C. libani A. Rich.). In the southern USA, various North American pines 

are used as hosts, especially loblolly (P. taeda L.), shortleaf (P. echinata

Mill.), and longleaf (P. palustris Mill.) 

The southern form of this weevil is found in the southeastern 

United States, north to Pennsylvania. The northern form (the old 

P. approximatus) is found from the Atlantic coast to Manitoba and 

Minnesota and south to North Carolina. The species is not present in the 

western United States. It is an invasive pest in some countries, including 

South Africa, where it is a pest in plantations of exotic pines.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Figure 1. Adult of eastern pine weevil, Pissodes nemorensis. (Gerald J. Lenhard, 

Louiana State University, Bugwood.org)

Images of Eastern

Pine Weevil
168 Forest Pest Insects in North America:

Images of Eastern

Pine Weevil (continued)

Figure 2. Eggs of eastern pine weevil. (Mark Fontaine, University of Florida, 

Bugwood.org)

Figure 3. Larvae of eastern pine weevil feeding in gallery (left) and mature larva 

(right) ready for pupation. (Left: Rayanne Lehman, Pennsylvania Department 

of Agriculture, Bugwood.org; right: Gerald J. Lenhard, Louiana State University, 

Bugwood.org)

Figure 4. Pupa of eastern pine weevil in cocoon (left), and cocoons on trunk 

with bark removed (right). (Left: Gerald J. Lenhard, Louiana State University, 

Bugwood.org; right: Chris Evans, River to River CWMA, Bugwood.org)
A Photographic Guide 169

The braconid parasitoid Coeloides pissodis (Ashmead) is an important 

natural enemy of eastern pine weevil. 

http://wiki.bugwood.org/Archive:South/Pissodes_nemorensis; Bugwood 

Wiki fact sheet on general biology of insect. 

http://www.eppo.org/QUARANTINE/insects/Pissodes_nemorensis/

PISONE_ds.pdf; quarantine data sheet on species for Europe; detailed 

information on biology and other topics. 

http://www.fabinet.up.ac.za/tpcpweb/pamphlets/pissodes.pdf; fact sheet 

on weevil as pest in South Africa providing considerable detail on 

biology and management. 

Gebeyehu, S. and M.J. Wingfield. 2003. Pine weevil Pissodes 

nemorensis: threat to South African pine plantations and options for 

control. South African Journal of Science 99(11/12): 531-536. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Eastern Pine Weevil

Articles
170 Forest Pest Insects in North America:

56. Whitefringed Beetles (Naupactus spp.) (Coleoptera: Curculionidae)

Orientation to Pest Whitefringed beetles, formerly regarded as a separate genus 

(Graphognathus), are now an informal “species group” within a much 

larger genus (Naupactus). The name whitefringed beetle comes from 

the white lines that run the length of the grey-to-brown body, two on 

each side, one above and one below the eye. There are four species, 

all invasive, in the United States: Naupactus leucoloma (Boheman), 

N. peregrinus (Buchanan), N. minor (Buchanan), and N. fecundus

(Buchanan). These beetles are pests of various agricultural crops, but 

also injure young pine seedlings when trees are planted into converted 

farmland in the southern United States. Adults feed on the foliage of 

hundreds of plant species, but damage is of minor importance. Larvae 

feed on roots and their damage is more serious, especially on crops or 

young pines in plantations and nurseries. Like the adults, the larvae feed 

on a diverse set of hosts, although their full host range is more difficult to 

document. The U.S. populations of all four species contain only females, 

although populations with males are found in the native range in southern 

South America. Adults have fused wing covers and cannot fly. Eggs are 

laid in masses on objects on or near the soil. Larvae drop into the soil 

where they feed on roots and then and pupate in earthen cells where they 

overwinter. There is only one generation per year.

Adults feed on nearly 400 species of plants, including many crops. 

Larvae feed on roots of some trees, such as peach (Prunus persica [L.] 

Batsch), pecan (Carya illinoinensis [Wangenh.] K.Koch), tung (Vernicia 

fordii [Hemsl.] Airy Shaw), willow (Salix), and pine (Pinus).

Originally from southern South America (Argentina, Peru, Chile, 

Uruguay), whitefringed beetles are found as invasive species in the 

United States from Florida north to Virginia and Illinois and west to 

Texas.

Hosts Commonly Attacked

Distribution

Figure 1. Adult of one of the whitefringed beetles, Naupactus peregrinus; see 

the enhanced white lines in drawing on right. (Left: Russ Ottens, University 

of Georgia, Bugwood.org; right: Department of Entomology and Nematology, 

University of Florida)

Images of 

Whitefringed Beetles
A Photographic Guide 171

Images of Whitefringed 

Beetles (continued)

Figure 2. Larva of a species of whitefringed beetle in root (left) and close up 

(right). (Left: Terry S. Price, Georgia Forestry Commission, Bugwood.org; right: 

Edward L. Barnard, Florida Department of Agriculture and Consumer Services, 

Bugwood.org)

Figure 3. Feeding damage of adult whitefringed beetles (left), and close up of 

adult feeding on blueberry leaf (right). (Left: Louis Tedders, USDA Agricultural 

Research Service, Bugwood.org; right: Jerry A. Payne, USDA Agricultural 

Research Service, Bugwood.org)

Figure 4. Feeding damage of larvae of whitefringed beetles on root of sycamore 

tree. (James Solomon, USDA Forest Service, Bugwood.org)
172 Forest Pest Insects in North America:

Images of Whitefringed 

Beetles (continued)

Figure 5. “Scalping” is the use of machinery to remove a thin layer of thatch 

and top soil before planting a new block of pine seedlings. (Edward L. Barnard, 

Florida Department of Agriculture and Consumer Services, Bugwood.org)

Figure 6. Unscalped pine plantation (left), showing loss of seedling establishment 

vs. scalped plot (right), where whitefringed beetles have been removed and 

pine seedling survival increased. (Both photos: Edward L. Barnard, Florida 

Department of Agriculture and Consumer Services, Bugwood.org)

Figure 7. Scalped plot (left of man) vs unscalped plot (right of man) in slash 

pine (Pinus elliottii Engelm.) plantation, showing cumulative effect of larvae of 

whitefringed beetles on growth of slash pines when beetle are suppressed before 

planting via “scalping” (removal of thatch and bit of top soil just before planting) 

or not. (Edward L. Barnard, Florida Department of Agriculture and Consumer 

Services, Bugwood.org)
A Photographic Guide 173

No information was located on specialized natural enemies of this group 

of beetles.

http://entnemdept.ufl.edu/creatures/field/beetles/whitefringed_beetles.

htm; University of Florida fact sheet on biology and control.

http://www.eppo.org/QUARANTINE/insects/Naupactus_leucoloma/

GRAGLE_ds.pdf; EPPO datasheet on this quarantine pest (from 

Europe’s point of view) containing information on biology and damage.

http://keys.lucidcentral.org/keys/sweetpotato/key/

Sweetpotato%20Diagnotes/media/html/TheProblems/PestRoot&StemInsects/WhitefringedBeetles/whitefringed%20beetle%2

0home.htm; factsheet of University of Queensland (Australia) with 

information on recognition, biology, ecology, and control.

Anderson W.H. 1938. A key to separate the larvae of the white-fringed 

beetle, Naupactus leucoloma Boh., from the larvae of closely related 

species. USDA Bureau of Entomology and Plant Quarantine Circular 

E-422. 3 p.

Ahmad, R. 1974. Studies on Graphognathus leucoloma (Boh.) Col.: 

Curculionidae) and its natural enemies in the central provinces of 

Argentina. Technical Bulletin No. 17, Commonwealth Institute of 

Biological Control: 19-28.

Harlan, D.P. and J.W. McGuire. 1977. Separation of four species of 

whitefringed beetles by measuring the length and width of the eggs 

(Coleoptera: Curculionidae). Journal of the Georgia Entomological 

Society 12: 125-128.

Lanteri, A.A. and A.E. Marvaldi. 1995. Graphognathus Buchanan a 

new synonym of Naupactus Dejean and systematics of the N. leucoloma

species group (Coleoptera: Curculionidae). Coleopterists Bulletin 49(3): 

206-228. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Whitefringed Beetles

Articles
174 Forest Pest Insects in North America:

57. Yellow-poplar Weevil, Odontopus calceatus (Say) (Coleoptera: 

Curculionidae) 

Orientation to Pest Yellow-poplar weevil, Odontopus calceatus (Say), feeds on yellowpoplar (Liriodendron tulipifera L.), magnolia (Magnolia), and sassafrass 

(Sassafras albidum [Nuttall] Nees.). The weevil overwinters as an adult 

and upon emergence, adults feed on buds or developing leaves. Eggs 

are laid in leaf veins and larvae feed as leafminers. Multiple larvae may 

coexist in a single common mined area. Outbreaks in yellow-poplar 

have occurred since 1960 in eastern Kentucky, Tennessee, Ohio, West 

Virginia, and Virginia.

This weevil feeds on yellow-poplar (L. tulipifera), magnolia (Magnolia), 

and sassafras (S. albidum).

This weevil is found throughout the eastern United States within the 

range of its hosts. 

Hosts Commonly Attacked

Distribution

Images of 

Yellow-poplar Weevil

Figure 1. Adults of yellow-poplar weevil, Odontopus calceatus, on leaf and (inset) 

close up. (Lacy L. Hyche, Auburn University, Bugwood.org; inset: Rich Kelly)
A Photographic Guide 175

Images of Yellow-poplar 

Weevil (continued)

Figure 2. Oviposition wounds (left) and eggs of yellow-poplar weevil (revealed by 

dissection) (right) in leaf vein. (Both photos: Lacy L. Hyche, Auburn University, 

Bugwood.org)

Figure 3. Larval mine (left) and larvae (right) (seen by opening mine) of yellowpoplar weevil. (Both photos: Lacy L. Hyche, Auburn University, Bugwood.org)

Figure 4. Cocoons in leaf (left) and pupa (right) (revealed by opening cocoon) 

of yellow-poplar weevil. (Both photos: Lacy L. Hyche, Auburn University, 

Bugwood.org)

Unspecified species of parasitoids have been noted to destroy up to 

50 percent of larvae in mines.

http://www.ca.uky.edu/entomology/entfacts/ef414.asp; University of 

Kentucky fact sheet. 

http://www.ag.auburn.edu/enpl/bulletins/lmweevil/lmweevil.htm; fact 

sheet of Auburn University, with extensive photos.

http://www.fs.fed.us/outernet/r6/nr/fid/fidls/fidl-125.pdf; USDA Forest 

Service Pest Leaflet.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Yellow-poplar Weevil
176 Forest Pest Insects in North America:

Burns, D.P. and L.P. Gibson. 1968. The leaf mining of yellow-poplar. The 

Canadian Entomologist 100: 421-429.

Hyche, L.L. 1994. The yellow-poplar leaf-mining weevil. A guide to 

recognition and habits in Alabama. Bulletin No. 622 of the Alabama 

Agricultural Experiment Station, Alabama Agricultural Experiment 

Station, Auburn University: 13 p. 

Articles on

Yellow-poplar Weevil
A Photographic Guide 177

58. Native Elm Bark Beetle, Hylurgopinus rufipes (Eichhoff) (Coleoptera: 

Curculionidae, Scolytinae)

Orientation to Pest Native elm bark beetle, Hylurgopinus rufipes (Eichhoff), is a native 

North American insect associated with various species of elm and other 

trees. Before the introduction of the exotic pathogen causing Dutch 

elm disease, this insect was of minor importance. During the historical 

period of mass epidemics of Dutch elm disease, this native bark beetle 

served as a vector of the pathogen. This process continues in wild lands 

where native elms survive and reproduce before succumbing to Dutch 

elm disease. Although H. rufipes has been displaced over much of its 

range by the introduced smaller European elm bark beetle (Scolytus 

multistriatus [Marsham]), H. rufipes remains the dominant vector of 

Dutch elm disease in northern areas where S. multistriatus is limited by 

low temperatures. Adult beetles emerge in early spring and fly to healthy 

elms to feed for a short period in the bark of branches and twigs. After 

feeding, beetles fly to dying and recently dead trees for oviposition. 

Females construct egg galleries that are oriented horizontally, across the 

grain of the wood. Eggs are laid along the egg gallery and larvae feed in 

tunnels that run parallel to the grain and perpendicular to the egg gallery. 

Larvae pupate in small cells at the ends of the feeding gallery. In some 

instances, larvae and newly developed adults will overwinter in these 

galleries, with adults emerging the following spring through small round 

exit holes. At other times, adults emerge before winter; these adults fly to 

healthy elm trees to feed on branches and to chew overwintering galleries 

in the bark, generally of the lower stem. If as larvae these adults had 

developed in trees dying from Dutch elm disease, they are very likely to 

carry spores of the fungus that causes Dutch elm disease. When they visit 

healthy elm trees to feed on branches or to create overwintering galleries, 

these beetles can transmit the pathogen. There are one to two generations 

of this bark beetle per year, depending on location. 

Rock (Ulmus thomasii Sarg.) and American elm (U. americana L.) are 

the major hosts of this bark beetle, but it also attacks American basswood 

(Tilia americana L.), and species of ash (Fraxinus).

This native bark beetle was formerly common throughout eastern North 

America from northern Alabama and Mississippi to southern Canada, 

but it has been displaced over most of this area by the introduced smaller 

European elm bark beetle. It is, however, still common in colder areas 

such as northern New York, New England, northern Minnesota, and 

southern Canada, where the smaller European elm bark beetle does not 

survive winter temperatures. 

Hosts Commonly Attacked

Distribution
178 Forest Pest Insects in North America:

Images of Native

Elm Bark Beetle

Figure 1. Adult native elm bark beetle, Hylurgopinus rufipes. (J.R. Baker and 

S.B. Bambara, North Carolina State University, Bugwood.org)

Figure 2. Egg gallery 

(horizontal) and larval 

galleries (vertical) 

of the native elm 

bark beetle. (John 

A. Williams, USDA 

Forest Service, 

Bugwood.org)
A Photographic Guide 179

Images of Native Elm 

Bark Beetle (continued)

Figure 3. Historical record of the change the new pathogen made in the 

importance of this bark beetle. (Darren Blackford, USDA Forest Service, 

Bugwood.org)

Figure 4. Two views of American elms dying of Dutch elm disease. (Left: 

Linda Haugen, USDA Forest Service, Bugwood.org; right: Roland J. Stipes, 

Virginia Polytechnic Institute and State University, Bugwood.org)
180 Forest Pest Insects in North America:

Images of Native Elm 

Bark Beetle (continued)

Figure 5. Streaking and discoloration of the vascular tissue in elms infected with 

Dutch elm disease. (North Carolina Forest Service Archive, Bugwood.org)

Figure 6. The clerid Enoclerus nigripes, an important predator of the native elm 

bark beetle. (Charley Eiseman, Bugwood.org)

The major predator of this bark beetle in Connecticut is the clerid 

Enoclerus nirgripes Say and the principal parasitoid is Spathius 

canadensis Ashmead.

http://www.extension.umn.edu/distribution/horticulture/DG1420.html; 

fact sheet from the University of Minnesota.

http://www.na.fs.fed.us/spfo/pubs/howtos/ht_ded/ht_ded.htm#intro; 

recognition and management of Dutch elm disease.

http://imfc.cfl.scf.rncan.gc.ca/insecte-insect-eng.asp?geID=2850. Natural 

Resources Canada fact sheet.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Native Elm Bark Beetle
A Photographic Guide 181

Articles Thompson, H.E. and J.G. Matthysse. 1972. Role of the native elm bark 

beetle, Hylurgopinus rufipes (Eichh.), in transmission of the Dutch 

elm disease pathogen, Ceratocystis ulmi (Buisman) C. Moreau. Search 

Agriculture (Entomology) 2(1,V): 16 p.

Gardiner, L.M. 1981. Seasonal activity of the native elm bark beetle, 

Hylurgopinus rufipes, in central Ontario (Coleoptera: Scolytidae). 

The Canadian Entomologist 113: 341-348.
182 Forest Pest Insects in North America:

59. Smaller European Elm Bark Beetle, Scolytus multistriatus (Marsham) 

(Coleoptera: Curculionidae, Scolytinae)

Orientation to Pest Smaller European elm bark beetle, Scolytus multistriatus (Marsham), is 

an introduced bark beetle that is one of the two main vectors of Dutch 

elm disease (along with the native elm bark beetle, Hylurgopinus rufipes

[Eichhoff]) in the eastern United States and Canada. It was brought to 

North America through the importation of unbarked elm logs containing 

live brood of the pest. It breeds in various species of elm, but the greatest 

damage is done to American elm (Ulmus americana L.). It is widely 

distributed in the United States. The biology of this species is much 

the same as for the native elm bark beetle. Adults fly to healthy elm 

trees in the spring, where they feed on twigs, infecting them with the 

fungal pathogen (Ophiostoma ulmi [Buisman] Melin and Nannf.) that 

causes Dutch elm disease. Trees that are stressed by this disease or other 

factors are attacked by females for breeding. Eggs are laid in galleries 

that females dig under the bark of the tree. Larvae develop in galleries, 

feeding in the cambium. Mature larvae overwinter in their galleries, 

pupating in spring and producing a new flight of adults. Emergence 

holes have a characteristic “shot hole” appearance. Mass attack on 

stressed trees is mediated, as in many bark beetles, via an aggregation 

pheromone. This beetle has displaced the native elm bark beetle in many 

parts of North America, except in the coldest areas. 

Smaller European bark beetle attacks all species of Elm (Ulmus) and the 

Japanese species Zelkova serrata (Thunb.) Makino.

This invasive bark beetle is found in southern Canada and most of the 

United States except some parts of Florida and Maine. 

Hosts Commonly Attacked

Distribution

Figure 1. Adult of smaller European elm bark beetle, Scolytus multistriatus. 

(Left: J.R. Baker and S.B. Bambara, North Carolina State University, 

Bugwood.org; right: Maja Jurc, University of Ljubljana, Bugwood.org)

Images of Smaller

European Bark Beetle
A Photographic Guide 183

Images of Smaller European

Bark Beetle (continued)

Figure 2. Elm branch with feeding in crotch from adults of smaller European elm 

bark beetle. (Joseph O’Brien, USDA Forest Service, Bugwood.org)

Figure 3. Galleries and brood of smaller European elm bark beetle; central 

galleries between “wings” are oviposition galleries and the two “wings” are groups 

of larval galleries; larvae are visible at ends of many galleries in photo on left. 

(Left: Joseph O’Brien, USDA Forest Service, Bugwood.org; right: Beat Forster, 

Swiss Federal Institute for Forest, Snow and Landscape Research, 

Bugwood.org)

Figure 4. Round 

emergence holes of the 

smaller European elm 

bark beetle. (J.R. Baker 

and S.B. Bambara, 

North Carolina State 

University, Bugwood.org)
184 Forest Pest Insects in North America:

Images of Smaller European

Bark Beetle (continued)

Figure 5. Two views of American elms dying of Dutch elm disease. (Left: 

Linda Haugen, USDA Forest Service, Bugwood.org; right: Roland J. Stipes, 

Virginia Polytechnic Institute and State University, Bugwood.org)

Figure 6. Two views of the streaking and discoloration of the vascular tissue 

in elms infected with Dutch elm disease. (Left: Joseph LaForest, University 

of Georgia, Bugwood.org; right: North Carolina Forest Service Archive, 

Bugwood.org)
A Photographic Guide 185

In Europe, several parasitoids are known to attack S. multistriatus. 

Three of these—Dendrosoter protuberans (Nees), Ecphylus silesicacus

(Ratzburg), and Coeloides scolyticida Wesm.—have been introduced 

into the United States. However, densities of this invasive bark beetle 

have not been compared between Europe and North America, to see 

if they were higher in North America than Europe at the time of these 

introductions. Nor have studies determined if these introductions (some 

of which did result in establishment) reduced the abundance of this bark 

beetle. Until recently whether or not this biological control effort had any 

effect on the target insect was a moot point, as sufficient elm bark beetles 

remained to allow the Dutch elm disease epidemic to go unchecked, 

destroying most native elms. The picture is further complicated by 

the fact that the pathogen, believed to be of Asian origin, has recently 

evolved to form a new, more aggressive form, Ophiostoma novo-ulmi

Brasier. This new pathogen has spread from the American midwestern 

states into other regions of North America, replacing the form of the 

pathogen introduced in North America in the 1940s. Nevertheless, the 

dynamics of this system in the context of replanting disease-resistant 

American elms in wildlands should now be revisited.

http://www.ento.okstate.edu/ddd/insects/smeurelmbark.htm; fact sheet of 

Oklahoma State University.

http://crawford.tardigrade.net/bugs/BugofMonth38.html; Bug of the 

Month fact sheet.

http://aces.nmsu.edu/ces/plantclinic/documents/o-03-barkbeetles.pdf; 

New Mexico fact sheet on bark beetles in general.

Schroder, D. 1974. Investigations on the prospects for biological 

control of scolytids on elms as a means of reducing Dutch elm disease. 

Zeitschrift für Angewandte Entomologie 76(2): 150-159. (In German). 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Smaller European

Bark Beetle

Articles
186 Forest Pest Insects in North America:

60. Spruce Beetle, Dendroctonus rufipennis (Kirby) (Coleoptera: 

Curculionidae, Scolytinae) 

Orientation to Pest Spruce beetle, Dendroctonus rufipennis (Kirby), is a native North 

American bark beetle that usually develops in wind-thrown, over mature, 

or weakened trees, resources that normally occur at low densities in 

forests. The biology of the beetle is similar to that of many bark beetles, 

with females laying eggs in tunnels (egg galleries), from which larvae 

then begin to feed, forming larval galleries. In this species young 

larvae often feed in common galleries, but then produce individual 

galleries as they mature. Larvae pupate at the end of their galleries, and 

overwinter as either larvae or new adults in the galleries. Spruce beetles 

generally require two years to complete their life cycle. However, when 

temperatures are warmer than normal a generation can be completed in 

one year. When two years are required, development is not synchronized 

and beetles emerge and attack trees each year. Spruce beetle outbreaks 

are associated with warmer than usual weather, and are often triggered by 

disturbance events such as avalanches, storms, and logging. Outbreaks 

tend to occur in areas with an abundance of large spruce trees. Outbreaks 

occur several times each century, thinning large trees from stands over 

extensive areas. More severe outbreaks in which trees of most sizes 

and vigor classes are killed occur less frequently. Important outbreaks 

historically have occurred in Alaska and Utah. 

Spruce beetle attacks various species of native North America spruce 

(Picea).

This bark beetle is found throughout the spruce forests of North America.

Hosts Commonly Attacked

Distribution

Figure 1. Adult of spruce beetle, Dendroctonus rufipennis. (David McComb, 

USDA Forest Service, Bugwood.org)

Images of 

Spruce Beetle
A Photographic Guide 187

Images of Spruce 

Beetle (continued)

Figure 2. Female spruce beetle digging an oviposition gallery, with white eggs 

visible in upper left. (Edward H. Holsten, USDA Forest Service, Bugwood.org)

Figure 3. Spruce beetle larvae at ends of tunnels. (Edward H. Holsten, USDA 

Forest Service, Bugwood.org)

Figure 4. Pupae of spruce beetle in galleries. (Edward H. Holsten, USDA Forest 

Service, Bugwood.org)
188 Forest Pest Insects in North America:

Images of Spruce 

Beetle (continued)

Figure 5. Oviposition 

(vertical) and larval 

(horizontal) galleries of 

spruce beetle etched 

in wood under bark of 

spruce tree. (Darren 

Blackford, USDA Forest 

Service, Bugwood.org)

Figure 6. Pitch tubes (left) and frass (right) on spruce trunks are signs of spruce 

beetle attack. (Left: Darren Blackford, USDA Forest Service, Bugwood.org; right: 

A. Steven Munson, USDA Forest Service, Bugwood.org)
A Photographic Guide 189

Images of Spruce 

Beetle (continued)

Figure 7. Adult spruce beetles in galleries. (A. Steven Munson, USDA Forest 

Service, Bugwood.org)

Figure 8. Burning of stumps (left) or logging slash (right) after felling infested 

trees is intended to limit spruce beetle outbreaks. (Left: A. Steven Munson, USDA 

Forest Service, Bugwood.org; right: USDA Forest Service - Region 2 - Rocky 

Mountain Region Archive, USDA Forest Service, Bugwood.org)

Figure 9. Views of spruce trees killed by spruce beetle, at various physical 

scales (dead trees denoted in artificial color in photo on right). (Left: USDA

Forest Service - Ogden Archive, USDA Forest Service, Bugwood.org; right: 

William M. Ciesla, Forest Health Management International, Bugwood.org)
190 Forest Pest Insects in North America:

A variety of natural enemies have been recorded in the literature 

attacking spruce beetle brood (see Van Driesche et al., 1996 in USDA 

FS publication FHTET-96-19, URL given below), including several 

species of braconid parasitoids in the genus Coeloides. Also the role of 

woodpecker predation on brood has been studied. But the fundamental 

determinants of outbreaks of spruce beetle do not seem to be driven by 

natural enemies, but rather to be responses to weather, the amount of 

breeding material for the beetle at a site, and local and regional spruce 

stand conditions.

http://imfc.cfl.scf.rncan.gc.ca/insecte-insect-eng.asp?geID=2819; fact 

sheet of Natural Resources Canada.

http://www.forestpestbiocontrol.info/fact_sheets/documents/

arthropodpestsnortheastern_northcentral.pdf; USDA Forest Service 

publication FHTET-96-19, Van Driesche et al., 1996; see pages 55-57 

for information on natural enemies of this species.

http://na.fs.fed.us/spfo/pubs/fidls/sprucebeetle/sprucebeetle.htm; USDA

Forest Service Forest Insect and Disease Leaflet on spruce beetle.

Schmid, J.M. and R.H. Frye. 1976. Stand ratings for spruce beetles. Res. 

Note RM-309. USDA Forest Service, Rocky Mountain Forest and Range 

Experiment Station, Ft. Collins, Colorado: 4 p.

Schmid, J.M. and R.H. Frye. 1977. Spruce beetle in the Rockies. USDA

Forest Service, Rocky Mountain Forest and Range Experiment Station, 

General Technical Report RM-49. Ft. Collins, Colorado: 38 p.

Linton, D. A. and L. Safranyik, L. 1988. The spruce beetle Dendroctonus 

rufipennis (Kirby): an annotated bibliography 1885-1987. Information 

Report - Pacific Forestry Centre, Canadian Forestry Service (BC-X-298): 

39 p. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Spruce Beetle

Articles
A Photographic Guide 191

61. Black Turpentine Beetle, Dendroctonus terebrans (Olivier) (Coleoptera: 

Curculionidae, Scolytinae) 

Orientation to Pest Black turpentine beetle, Dendroctonus terebrans (Olivier), is a native, 

North American bark beetle that attacks various pines. Adults of this 

species are strongly attracted to odors of freshly cut pine stumps, 

where they are able to breed. In whole trees, eggs are primarily laid in 

the bottom 1-2 meters of the boles as well as roots of weakened trees. 

Eggs are laid in large oviposition galleries created by females with 

the help of males. Larvae feed collectively in large galleries. Pupation 

takes place in pupal cells constructed in the corky bark or between 

the bark and the wood. In the northern part of the range, adults are the 

overwintering stage. In southern areas, all stages may be present all year. 

Damage can occur in healthy trees as well as stressed trees, and damage 

in turpentine orchards can be severe. The black turpentine beetle is 

often found attacking trees in association with the southern pine beetle 

(Dendroctonus frontalis Zimmermann) or various species of southern 

pine engraver beetles (Ips spp.).

Hosts of black turpentine beetle include all species of southern pines, but 

especially loblolly (Pinus taeda L.) and slash (P. elliottii Engelm.) pines. 

In the northern part of its range, black turpentine beetle attacks various 

conifers, including black (P. thunbergiana Franco) and pitch (P. rigida

Miller) pines and red spruce (Picea rubens Sargent). 

This bark beetle is found in the eastern United States from Florida 

west to Missouri and Texas and north to coastal areas of southern New 

England.

Hosts Commonly Attacked

Distribution

Images of Black

Turpentine Beetle

Figure 1. Adults of black turpentine beetle, Dendroctonus terebrans. (Left: 

David T. Almquist, University of Florida, Bugwood.org; right: Clemson University 

- USDA Cooperative Extension Slide Series, Bugwood.org)
192 Forest Pest Insects in North America:

Images of Black

Turpentine Beetle

(continued)

Figure 2. Black 

turpentine beetle 

(bottom) is the largest 

of the five species 

of southern pine 

bark beetles. The 

other species (from 

top down) are: Ips 

avulsus (Eichhoff), Ips 

grandicollis (Eichhoff), 

Ips calligraphus

(Germar), and 

Dendroctonus frontalis

(Zimmermann). 

(Gerald J. Lenhard, 

Louiana State 

University, 

Bugwood.org)

Figure 3. Eggs of black turpentine beetle (white, above beetle on left). 

(Terry S. Price, Georgia Forestry Commission, Bugwood.org)
A Photographic Guide 193

Images of Black

Turpentine Beetle

(continued)

Figure 4. Larvae of black turpentine beetle in common feeding gallery (left); 

larvae enlarged (right). (Left: James R. Meeker, USDA Forest Service, 

Bugwood.org; right: Gerald J. Lenhard, Louiana State University, Bugwood.org)

Figure 5. Pupae of black turpentine beetle, in pupal cells, lower left. 

(Ronald F. Billings, Texas Forest Service, Bugwood.org)

Figure 6. Pitch tubes (left) are created by the tree where black turpentine beetles 

bore in the tree; during mass attack, there may be many pitch tubes in the lower 

bole area (right). (Left: USDA Forest Service Archive, USDA Forest Service, 

Bugwood.org; right: Ronald F. Billings, Texas Forest Service, Bugwood.org)
194 Forest Pest Insects in North America:

Images of Black

Turpentine Beetle

(continued)

Figure 7. Dying loblolly pines infested with both Ips beetles and black turpentine 

beetles. (Ronald F. Billings, Texas Forest Service, Bugwood.org)

Figure 8. The clerid Thanasimus dubius (red larva in lower center, top; and 

close up, bottom) is a common predator of brood of black turpentine beetles. 

(Top: North Carolina State University Archive, North Carolina State University, 

Bugwood.org; bottom: Gerald J. Lenhard, Louiana State University, 

Bugwood.org)
A Photographic Guide 195

Little is known about the specific natural enemies of this species. The 

clerid Thanasimus dubius (Fabricius) and the trogositid Temnochila 

virescens (Fabricius), predatory beetles that prey on many southern pine 

bark beetles, are found attacking brood of black turpentine beetles. 

http://entnemdept.ufl.edu/creatures/trees/beetles/black_turpentine_beetle.

htm; fact sheet of the University of Florida.

Barras, S.J. and T. Perry. 1971. Leptographium terebrantis sp. nov. 

associated with Dendroctonus terebrans in loblolly pine. Mycopathologia

43: 1-10.

Foltz, J.L., E.P. Merkel, and R.C. Wilkinson. 1984. Annotated 

bibliography of Dendroctonus terebrans (Oliver), Ips avulsus (Eichhoff), 

Ips grandicollis (Germar) in the southeastern USA. Monograph No. 12. 

Agricultural Experiment Station, University of Florida: 47 p. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Black Turpentine Beetle

Articles
196 Forest Pest Insects in North America:

62. Eastern Larch Beetle, Dendroctonus simplex (LeConte) (Coleoptera: 

Curculionidae, Scolytinae) 

Eastern larch beetle, Dendroctonus simplex (LeConte), is a native North 

American bark beetle whose only important host is eastern larch, Larix 

larcina (Du Roi ) K. Koch. The species overwinters as larvae or adults 

in galleries. Eggs are laid in groups along an egg gallery made by the 

female in the inner bark and outer sapwood. Larval tunnels are short 

and occur in the inner bark. There are up to three generations per year. 

Before the 1970s, this bark beetle was only known to attack dying or 

recently felled trees. Since then, however, a series of large outbreaks in 

healthy stands have occurred in both Canada and the United States. Some 

of these bark beetle outbreaks followed outbreaks of the defoliating 

larch sawfly Pristiphora erichsonii (Hartig), which had produced many 

stressed or dying larch trees. While the exact causes of these population 

fluctuations are unknown, some authors have attributed outbreaks to the 

maturing of larch stands over large areas, which lowers host resistance. 

Hosts of this species are eastern larch (L. larcina), and occasionally red 

spruce (Picea rubens Sargent).

This bark beetle is found in the United States from New England south 

to West Virginia, and west to Minnesota. It is also found in Alaska and 

in Canada from the Atlantic to the Pacific coast.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Figure 1. Adults of eastern larch beetle, Dendroctonus simplex, in galleries. 

(Thérèse Arcand - Natural Resources Canada, Canadian Forest Service)

Images of Eastern

Larch Beetle
A Photographic Guide 197

Figure 2. Eggs of eastern larch beetle. (Thérèse Arcand - Natural Resources 

Canada, Canadian Forest Service)

Figure 3. Larva of eastern larch beetle. (Thérèse Arcand - Natural Resources 

Canada, Canadian Forest Service)

Figure 4. Pupa of eastern larch beetle. (Thérèse Arcand - Natural Resources 

Canada, Canadian Forest Service)

Images of Eastern

Larch Beetle (continued)
198 Forest Pest Insects in North America:

Figure 5. Larval galleries at surface of wood made by eastern larch beetle. 

(Thérèse Arcand - Natural Resources Canada, Canadian Forest Service)

Eastern larch beetle has a large complex of natural enemies that have 

been studied in a number of locations (see Van Driesche et al. 1996 for a 

review). Some of the natural enemies reported include the dolichopodid 

fly, Medetera gaspensis Bickel, and the rhizophagid beetle, Rhizophagus 

dimidiatus Mannerheim, (both predators), and the parasitoids Spathius 

canadensis Ashmead (Braconidae), Rhopalicus tutela (Walker), and 

Roptrocerus xylophagorum (Ratzeburg). 

http://www.na.fs.fed.us/spfo/pubs/fidls/elb/elb.htm; a USDA Forest 

Service fact sheet, Forest Insect and Disease Leaflet #175, providing 

extensive detail on biology, hosts, distribution, and control of eastern 

larch beetle.

http://imfc.cfl.scf.rncan.gc.ca/insecte-insect-eng.asp?geID=2820; a 

Natural Resources Canada fact sheet.

Duncan, B. 1987. An illustrated guide to the identification and 

distribution of the species of Dendroctonus Erichson (Coleoptera: 

Scolytidae) in British Columbia. Journal of the Entomological Society 

of British Columbia 84: 101-112.

Langor, D.W. and A.G. Raske. 1988. Annotated bibliography of the 

eastern larch beetle, Dendroctonus simplex LeConte (Coleoptera: 

Scolytidae). Information Report - Newfoundland Forestry Centre, 

Forestry Canada (N-X-266), 1988: 38 p.

Langor, D.W. and A.G. Raske. 1988. Mortality factors and life tables of 

the eastern larch beetle, Dendroctonus simplex (Coleoptera: Scolytidae), 

in Newfoundland. Environmental Entomology 17: 959-963.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Eastern Larch Beetle

Articles

Images of Eastern

Larch Beetle (continued)
A Photographic Guide 199

Langor, D.W. and A.G.A. Raske. 1989. A history of the eastern larch 

beetle, Dendroctonus simplex (Coleoptera: Scolytidae), in North 

America. Great Lakes Entomologist 22: 139-154.

Van Driesche, R.G., S. Healy, and R.C. Reardon. 1996. Biological 

control of arthropod pests of the northeastern and north central 

forests in the United States: a review and recommendations. USDA

FS, FHTET-96-19, Morgantown, West Virginia: 58-59. (Available 

at http://www.forestpestbiocontrol.info/fact_sheets/documents/

arthropodpestsnortheastern_northcentral.pdf).

Articles (continued)
200 Forest Pest Insects in North America:

Southern pine beetle, Dendroctonus frontalis (Zimmermann), is the most 

destructive bark beetle attacking pines in the southern United States. It is 

a native North American species that also occurs in Mexico and Central 

America. Its principal hosts are yellow pines, especially shortleaf (Pinus 

echinata Mill.), loblolly (P. taeda L.), Virginia (P. virginiana Mill.), and 

pitch (P. rigida Mill.) pines. Beetles overwinter in all stages and timing 

of adult emergence in spring varies with location, from mid-March to 

June. Bark areas from which adults have emerged have a shot-hole-like 

appearance. Attack by adults during warm days in winter is usually on 

previously attacked trees and is focused initially on the mid to upper part 

of the tree. Females construct a nuptial chamber, where they are later 

joined by males. An S-shaped oviposition gallery is then constructed, 

along which eggs are laid. Larval galleries are at right angles to the 

oviposition gallery and score the wood. Larval tunnels are primarily in 

the bark and pupation occurs at the end of the larval gallery. With each 

new generation, infested areas expand, sometimes covering very large 

areas. In western North Carolina there are three to five generations per 

year and up to seven per year further south. The generations overlap, 

so in active infestations, all life stages of the beetle are present at any 

one time and adult beetles emerge and attack new trees daily when 

temperatures allow. Trees under 15 years of age or 5 cm in diameter are 

rarely attacked. Infestations typically begin in stands of trees stressed 

by high tree density, logging damage, lightning, dryness, flooding, or 

disease. Trees die either because they are girdled by larval galleries, 

or because of the effects of a blue stain fungus (Ceratocystis minor

[Hedgc.] Hunt), which is vectored by the beetle. Damage from outbreaks 

is reduced somewhat by managing stands to reduce tree stress and by 

halting the expansion of initial spots using salvage (cut-and-remove) or 

cut-and-leave control methods. 

Principal species in which reproduction of southern pine beetle occurs 

are the yellow pines, especially shortleaf (P. echinata), loblolly (P. 

taeda), Virginia (P. virginiana), and pitch (P. rigida) pines. The beetle 

also attacks species such as longleaf (P. palustris Miller) and slash 

(P. elliottii Engelm.) pines, but reproduction is often less successful 

due to heavy resin flow. 

This bark beetle is found throughout the southeastern and southern parts 

of the United States, as well as Mexico and parts of Central America.

Orientation to Pest

Hosts Commonly Attacked

Distribution

63. Southern Pine Beetle, Dendroctonus frontalis (Zimmermann) 

(Coleoptera: Curculionidae, Scolytinae) 
A Photographic Guide 201

Figure 1. Distribution of southern 

pine beetle, Dendroctonus frontalis. 

(Eastern Forest Environmental 

Threat Assessment Center • Threat 

Summary)

Images of 

Southern Pine Beetle

Figure 2. Adults of southern pine beetle; left, beetle in flight. (Both photos: 

Erich G. Vallery, USDA Forest Service - SRS-4552, Bugwood.org)

Figure 3. The head of the southern pine beetle is diagnostic for the species. The 

head is broad, with a distinct notch or frontal groove on male beetles, bordered 

by distinct projections or tubercules on either side of the groove. The antennae 

are seven-segmented, consisting of the basal pedicel, elongated scape, foursegmented funicle, and an enlarged club. (Pest and Diseases Image Library, 

Bugwood.org)
202 Forest Pest Insects in North America:

Images of Southern Pine 

Beetle (continued)

Figure 4. Egg of southern pine beetle. (USDA Forest Service Archive, USDA 

Forest Service, Bugwood.org)

Figure 5. Life cycle diagram of southern pine beetle (left), showing various 

larval stages; view of southern pine beetle larva in wood (right). (Left: Ronald F. 

Billings, Texas Forest Service, Bugwood.org; right: Erich G. Vallery, USDA Forest 

Service - SRS-4552, Bugwood.org)

Figure 6. Pupae of southern pine beetle. (Ronald F. Billings, Texas Forest 

Service, Bugwood.org)
A Photographic Guide 203

Images of Southern Pine 

Beetle (continued)

Figure 7. Young adults of southern pine beetle in galleries, ready to emerge. 

(Erich G. Vallery, USDA Forest Service - SRS-4552, Bugwood.org)

Figure 8. Pitch tubes on pines (left) are a sign of bark beetles such as southern 

pine beetle; close-up of pitch tube (center), and female southern pine beetle 

with entrance hole in pitch tube, right. (All photos: Erich G. Vallery, USDA Forest 

Service - SRS-4552, Bugwood.org)

Figure 9. Galleries of southern pine beetle and associated blue stain (left), and 

view of blue stain fungus (right) in cross section slice of trunk. (Left: Erich G. 

Vallery, USDA Forest Service - SRS-4552, Bugwood.org; right: Ronald F. Billings, 

Texas Forest Service, Bugwood.org)
204 Forest Pest Insects in North America:

Images of Southern Pine 

Beetle (continued)

Figure 10. Initial point of outbreak (“spot”) of southern pine beetle (left) and 

larger area of damage, to loblolly pine (right). (Left: Erich G. Vallery, USDA 

Forest Service - SRS-4552, Bugwood.org; right: William M. Ciesla, Forest Health 

Management International, Bugwood.org)

Figure 11. Tree felling is a control method (left) used to prevent expansion of spot 

infestations (right, spot after infested trees have been removed). Infested trees 

and uninfested trees in a buffer zone are either cut and removed or cut and left 

in place, in either case for the purpose of stopping spot expansion. (Both photos: 

Ronald F. Billings, Texas Forest Service, Bugwood.org)

Figure 12. Larva of checkered beetle, Thanasimus dubius (Fabricius) (Cleridae) 

eating a southern pine beetle larva (top left) and close up of T. dubius larva (top 

right); adult of T. dubius with prey (bottom). (Top left: John Moser, USDA Forest 

Service, Bugwood.org; top right: Gerald J. Lenhard, Louiana State University, 

Bugwood.org; bottom: Erich G. Vallery, USDA Forest Service - SRS-4552, 

Bugwood.org)
A Photographic Guide 205

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Southern Pine Beetle

The most important natural enemies of southern pine beetles are 

predacious clerid beetles. These predators are attracted to the aggregation 

pheromone and host volatiles used in traps to assess southern pine 

beetle densities in particular stands. Comparison of pest and predator 

numbers caught in traps is used each spring throughout the southern and 

eastern United States to forecast southern pine beetle population trends 

(outbreaks or population declines) (Figure 13).

Figure 13. A decision chart to forecast southern pine beetle outbreaks, using 

information on density of the bark beetle and its clerid predator in traps baited 

with aggregation pheromone (developed by Ron Billings, Texas Forest Service) 

(see Billings and Upton, 2010).

http://entnemdept.ufl.edu/creatures/trees/southern_pine_beetle.htm; 

University of Florida fact sheet.

Fidgen, J. (2000). Southern pine beetle information directory. 

http://everest.ento.vt.edu/~salom/SPBinfodirect/spbinfodirect2.html 

(5 July 2001). 

http://www.barkbeetles.org/spb/spbbook/Index.html; a web rendering 

of the U.S. Department of Agriculture, Expanded Southern Pine Beetle 

Research and Applications Program, Forest Service, Science and 

Education Administration, Technical Bulletin 1631: [1980].

ftp://ftp.fao.org/docrep/fao/011/i0640e/i0640e10e.pdf; Bulletin of the 

United Nations, Food and Agriculture Organization.

http://www.barkbeetles.org/centralamerica/0605e.html; management 

of southern pine beetle in Central America.
206 Forest Pest Insects in North America:

Articles on

Southern Pine Beetle

Chellman, C.W. and R.C. Wilkinson. 1975. Recent history of southern 

pine beetle, Dendroctonus frontalis Zimm. (Col.; Scolytidae), in Florida. 

Florida Entomologist 58: 22. 

Dixon, W.N. and T.L. Payne. 1979. Aggregation of Thanasimus dubius

on trees under mass-attack by the southern pine beetle. Environmental 

Entomology 8: 178-181. 

Billings, R.F. and H.A. Pase III. 1979. A field guide for ground checking 

southern pine beetle spots. U.S. Department of Agriculture, Combined 

Forest Pest Research and Development Program, Agriculture Handbook 

No. 558: 19 p.

Swain, K.M. and M.C. Remion. 1981. Direct control methods for the 

southern pine beetle. U.S. Department of Agriculture, Combined Forest 

Pest Research and Development Program, Agriculture Handbook 

No. 575: 15 p.

Billings, R.F. and W.W. Upton. 1993. Effectiveness of synthetic 

behavioral chemicals for manipulation and control of southern pine 

beetle infestations in East Texas. USDA Forest Service, Southern Forest 

Experiment Station. General Technical Report: 555-568. 

Clarke, S.L. and J.T. Nowak. 2009. Southern pine beetle. Forest Insect 

and Disease Leaflet No. 49, USDA Forest Service, Portland, Oregon, 

United States. 8 p. 

Billings, R.F. and W.W. Upton. 2010. A methodology for assessing 

annual risk of southern pine beetle outbreaks across the Southern Region, 

using pheromone traps, p. 73-85. In: Pye, J.M., H.M. Rauscher, Y. Sands, 

D.C. Lee, J.S. Beatty (tech. eds.). 2010. Advances in threat assessment 

and their application to forest and rangeland management. General 

Technical Report PNW-GTR-802. U.S. Department of Agriculture, 

Forest Service, Pacific Northwest and Southern Research Stations, 

Portland, Oregon, United States. 708 p., 2 vol. (Image available at 

http://www.threats.forestencyclopedia.net/p/p3291).
A Photographic Guide 207

64. Western Pine Beetle, Dendroctonus brevicomis LeConte (Coleoptera: 

Curculionidae, Scolytinae) 

Western pine beetle, Dendroctonus brevicomis LeConte, is a native 

bark beetle of the western United States that attacks and kills ponderosa 

(Pinus ponderosa Douglas ex P & C. Lawson) and Coulter (P. coulteri

D. Don) pines greater than 15 cm in diameter, regardless of age or 

vigor, including apparently healthy trees. Outbreaks are most common 

in dense, even-age stands, but also occur in areas of mixed conifer 

species. Mortality is often subtle yet significant when large old trees 

are killed individually by the beetle. Large outbreaks are common and 

over one million trees (more than 1 billion board feet of timber) may be 

killed each year during outbreaks. Outbreaks have been known to occur 

following wildfires in ponderosa pine stands. Beetle attacks are first 

visible due to pitch tubes that form at the sites where female beetles bore 

into the tree to create oviposition galleries. However, pitch tubes of this 

species are less conspicuous than for other bark beetles and frequently 

are not seen at all. Attacking adult beetles carry spores of a blue-staining 

fungus, Ceratocystis minor (Hedg.), which contributes to tree death by 

blocking the water-conducting vessels in the wood. The egg galleries are 

about the width of an adult beetle and are usually tightly packed with 

boring dust. There are two to four generations per year, depending on 

latitude and altitude. Eggs are laid singly along the oviposition gallery 

and larvae then make short lateral galleries as they feed. As is true for 

many bark beetles, aggregation pheromones produced by the beetle 

coordinate a mass attack on selected trees. Thinning of trees to reduce 

density can be used to reduce stand susceptibility to mortality from 

western pine beetle.

This beetle attacks ponderosa (P. ponderosa Douglas ex P & C. Lawson) 

and Coulter (P. coulteri D. Don) pines.

Western pine beetle is most damaging 

in California, but its range extends 

northward into Oregon, Washington, 

Idaho, and southern British Columbia, as 

well as eastward into Montana, Nevada, 

Utah, Colorado, Arizona, New Mexico, 

and western Texas. It also occurs in 

northwestern Mexico.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Figure 1. Distribution (in western 

North America) of the western pine 

beetle, Dendroctonus brevicomis. 

(USDA Forest Service • Forest 

Insect & Disease Leaflet 1)
208 Forest Pest Insects in North America:

Images of 

Western Pine Beetle

Figure 2. Adult of western pine beetle, Dendroctonus brevicomis (left), and close 

up of head (right); note lack of rows of tubercules on either side of the frontal 

groove, as are present in the southern pine beetle, Dendroctonus frontalis

(Zimmermann). (Left: Erich G. Vallery, USDA Forest Service - SRS-4552, 

Bugwood.org; right: Pest and Diseases Image Library, Bugwood.org)

Figure 3. Pitch tubes 

of western pine beetle. 

(Kenneth E. Gibson, 

USDA Forest Service, 

Bugwood.org)
A Photographic Guide 209

Images of Western

Pine Beetle (continued)

Figure 4. Larvae of 

western pine beetle. 

(Ladd Livingston, Idaho 

Department of Lands, 

Bugwood.org)

Figure 5. Galleries of western pine beetle in ponderosa pine. (Left: USDA 

Forest Service - Ogden Archive, USDA Forest Service, Bugwood.org; right: 

William M. Ciesla, Forest Health Management International, Bugwood.org)

Figure 6. Shot holes 

formed in ponderosa 

pine by emergence of 

western pine beetles. 

(Donald Owen, 

California Department 

of Forestry and Fire 

Protection, 

Bugwood.org)
210 Forest Pest Insects in North America:

Images of Western

Pine Beetle (continued)

Figure 7. Two views of 

stands of ponderosa 

pines killed by western 

pine beetle. (Top: 

William M. Ciesla, 

Forest Health 

Management 

International, 

Bugwood.org; 

bottom: James Everitt, 

Bugwood.org)

Figure 8. The predacious clerid beetle Enoclerus lecontei, a predator of western 

pine beetle. (Brytten Steed, USDA Forest Service, Bugwood.org)
A Photographic Guide 211

Important predators of brood of western pine beetle are the clerid beetles 

Enoclerus lecontei (Wolcott) and Enoclerus sphegeus Fabricius, as well 

as the blue-green ostomid Temnochila chlorodia Mannerheim and the 

fly Medetera aldrichii Wheeler. Common parasites are Roptrocerus 

xylophagorum Ratzeburg, Dinotiscus burkei Crawford, and Coeloides sp. 

nr. brunneri Vierick.

http://www.forestpests.org/acrobat/fidl1.pdf; USDA Forest Service, 

Forest Insect and Disease Leaflet #1.

http://forestry.nv.gov/forestry-resources/forest-health/western-pinebeetle/; fact sheet of the Nevada Division of Forestry.

Miller, J.M. and F.P. Keen. 1960. Biology and control of the western pine 

beetle. U.S. Department of Agriculture Misc. Publ. 800, Washington, 

DC: 381 p.

Stark, R.W. and D.L. Dahlsten (eds.). 1970. Studies on the population 

dynamics of the western pine beetle, Dendroctonus brevicomis

LeConte (Coleoptera: Scolytidae). University of California, Division of 

Agricultural Science, Berkeley, California, USA: 174 p.

Wallin, K.F., T.E. Kolb, K.R. Skov, and M. Wagner. 2008. Forest 

management treatments, tree resistance, and bark beetle resource 

utilization in ponderosa pine forests of northern Arizona. Forest Ecology 

and Management 255(8/9): 3263-3269. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Western Pine Beetle

Articles
212 Forest Pest Insects in North America:

65. Jeffrey Pine Beetle, Dendroctonus jeffreyi Hopkins (Coleoptera: 

Curculionidae, Scolytinae) 

Orientation to Pest Jeffrey pine beetle, Dendroctonus jeffreyi Hopkins, is a native North 

American bark beetle that attacks only Jeffrey pine (Pinus jeffreyi Grev. 

and Balf.) and it is that tree’s most serious insect pest. This pine beetle 

occurs in the Sierra Nevada wherever Jeffrey pine is present. In most 

cases this beetle occurs at low densities and attacks only small numbers 

of slow growing trees with reduced vigor. However, large outbreaks can 

occur when forest conditions are favorable, especially during extended 

droughts. Adults emerge from infested trees in April or May. Mass attack 

is initiated by colonizing beetles, which release aggregation pheromones. 

Females bore in and excavate a vertical gallery where they lay their 

eggs. The oviposition gallery is packed with boring dust, and larvae 

later form short individual lateral tunnels where they feed. Jeffrey pine 

beetles overwinter as larvae or as pupae in chambers excavated at the 

end of larval galleries. Depending on local climate there are one or two 

generations per year. Beetles infect trees with a blue-stain fungus, which 

kills the tree by clogging the tree’s vascular system. Signs of attack 

include pitch tubes on the mid or lower trunk. In weak trees pitch tubes 

may be absent. 

This beetle attacks only Jeffrey pine (P. jeffreyi).

Jeffrey pine beetle is found within the range of Jeffrey pine, principally 

in California, with the exceptions of the San Jacinto, Santa Rosa, and 

Luguna mountain ranges of southern California, where this bark beetle 

has not been observed.

Hosts Commonly Attacked

Distribution

Images of 

Jeffrey Pine Beetle

Figure 1. Adults of Jeffrey pine beetle, Dendroctonus jeffreyi. (Both photos: 

Erich G. Vallery, USDA Forest Service - SRS-4552, Bugwood.org)
A Photographic Guide 213

Images of Jeffrey 

Pine Beetle (continued)

Figure 2. Eggs of Jeffrey pine beetle in oviposition gallery (above dark line of 

gallery). (Dave Powell, USDA Forest Service, Bugwood.org)

Figure 3. Larva of Jeffrey pine beetle, removed from gallery. (Erich G. Vallery, 

USDA Forest Service - SRS-4552, Bugwood.org)
214 Forest Pest Insects in North America:

Images of Jeffrey 

Pine Beetle (continued)

Figure 4. Pupa of Jeffrey 

pine beetle. (tia smith, 

Bugwood.org)

Figure 5. Galleries of 

adults (vertical) and 

larvae (horizontal) of 

Jeffrey pine beetle. 

(Darren Blackford, 

USDA Forest Service, 

Bugwood.org)
A Photographic Guide 215

Images of Jeffrey 

Pine Beetle (continued)

Figure 6. Pines killed by Jeffrey pine beetle near Lake Tahoe, California. 

(Darren Blackford, USDA Forest Service, Bugwood.org)

Natural enemies of this bark beetle have received little attention, 

but likely are similar to those groups attacking western pine beetle 

(Dendroctonus brevicomis LeConte).

http://forestry.nv.gov/forestry-resources/forest-health/jeffery-pine-beetle/; 

fact sheet of the Nevada Division of Forestry.

http://www.fs.fed.us/r6/nr/wildlife/decaid/IandDSpecies/

Jeffrey%20pine%20beetle.html; USDA Forest Service fact sheet. 

http://www.unce.unr.edu/publications/files/ho/other/fs9840.pdf; fact 

sheet of the University of Nevada at Reno.

Smith, R.H., B.E. Wickman, R.C. Hall, C.J. DeMars, and G.T. Ferrell. 

1981. The California pine risk-rating system: its development, use and 

relationship to other systems. In: Hedden, R.L., S.J. Barras, J.E. Coster. 

(tech. coords.). Hazard-rating systems in forest insect pest management: 

symposium proceedings. Athens, Georgia, July 31-August 1, 1980. 

General Technical Report WO-27, USDA Forest Service, Washington, 

DC: 53-69.

Smith, S.L., R.B. Borys, and P.J. Shea. 2008. Jeffrey pine beetle. USDA 

Forest Service, Forest Pest Leaflet 11: 7 p.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Jeffrey Pine Beetle

Articles
216 Forest Pest Insects in North America:

66. Mountain Pine Beetle, Dendroctonus ponderosae Hopkins (Coleoptera: 

Curculionidae, Scolytinae) 

Orientation to Pest Mountain pine beetle, Dendroctonus ponderosae Hopkins, a native North 

American species, is the most destructive bark beetle of the western 

United States and Canada, where it occurs widely on a variety of pines, 

including lodgepole (Pinus contorta Douglas), ponderosa (P. ponderosa

Douglas ex C. Lawson), western white (P. monticola Douglas ex D. 

Don), whitebark (P. albicaulis Engelmann) and sugar (P. lambertiana

Douglas) pines. Historically, highly destructive outbreaks of this species 

have occurred repeatedly, decimating mature forests of such species as 

lodgepole pine over extensive areas. All trees above 10 cm in diameter 

are susceptible to attack. Beetle attacks are usually concentrated along 

the main trunk, from about one meter above the ground up to the middle 

branches. As with many bark beetles, signs of infestations include 

pitch tubes on the trunk, red boring dust in bark crevices, discoloration 

of foliage as trees die, and blue discoloration of the wood caused by 

several associated fungi: Grosmannia clavigera (Robinson-Jeffrey and 

Davidson) Zipfel, de Beer, and Wingfield; and Ophiostoma montium

(Rumbold) von Arx. Females dig egg galleries under the bark and lay 

eggs on alternate sides of the gallery. Larvae excavate short feeding 

tunnels at right angles to the egg gallery. Mature larvae construct pupal 

cells at the ends of the larval galleries, where larvae pupate and from 

which new adults later emerge. Most commonly there is one generation 

per year but there may be only one every two years in the coldest parts 

of the species’ range. Larvae and adults are the overwintering stages.

The principal hosts of this beetle are lodgepole (P. contorta), sugar 

(P. lambertiana), western white (P. monticola), ponderosa (P. ponderosa), 

and whitebark (P. albicaulis) pines, but Pinus aristata Engelmann, 

P. balfouriana Balfour, P. coulteri D. Don, P. edulis Engelmann, 

P. flexilis E. James, P. strobiformis Engelm., P. longaeva D.K. Bailey, 

and P. monophylla Torr. and Frém. have also been recorded as hosts.

Mountain pine beetle is found 

throughout the pine forests of western 

Canada, the western United States and 

northern Mexico (Baja California). 

Hosts Commonly Attacked

Distribution

Figure 1. Distribution of mountain pine 

beetle, Dendroctonus ponderosae, 

in North America. (USDA Forest 

Service • Forest Insect 

& Disease Leaflet 2)
A Photographic Guide 217

Images of 

Mountain Pine Beetle

Figure 2. Adults of mountain pine beetle. (Left: USDA Forest Service - Region 2 

- Rocky Mountain Region Archive, USDA Forest Service, Bugwood.org; right: 

Ron Long, Simon Fraser University, Bugwood.org)

Figure 3. Pitch tubes of mountain pine beetle during initiation of attack. (Left: 

Steven Katovich, USDA Forest Service, Bugwood.org; right: Leslie Chong, 

Simon Fraser University, Bugwood.org)

Figure 4. Larvae of mountain pine beetle in their galleries. (Left: USDA Forest 

Service - Ogden Archive, USDA Forest Service, Bugwood.org; right: Ladd 

Livingston, Idaho Department of Lands, Bugwood.org)
218 Forest Pest Insects in North America:

Images of Mountain 

Pine Beetle (continued)

Figure 5. Pupae and adults (left) of mountain pine beetle; callow adult (right). 

(Left: USDA Forest Service - Ogden Archive, USDA Forest Service, 

Bugwood.org; right: USDA Forest Service - Region 2 - Rocky Mountain 

Region Archive, USDA Forest Service, Bugwood.org)

Figure 6. Galleries of mountain pine beetle (left) and galleries and blue staining 

of wood (right). (Left: Leslie Chong, Simon Fraser University, Bugwood.org; 

right: Carl Jorgensen, USDA Forest Service, Bugwood.org)

Figure 7. Lodgepole pines (left) killed by mountain pine beetle; view of infested 

pines (right). (Left: USDA Forest Service - Ogden Archive, USDA Forest Service, 

Bugwood.org; right: USDA Forest Service - Region 2 - Rocky Mountain Region 

Archive, USDA Forest Service, Bugwood.org)
A Photographic Guide 219

Images of Mountain 

Pine Beetle (continued)

Figure 8. Adult of Enoclerus sphegeus Fabricus, a predator of mountain pine 

beetle. (Brytten Steed, USDA Forest Service, Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

Natural enemies of mountain pine beetle include predaceous insects such 

as Enoclerus sphegeus Fabricius, Temnochila chlorodia Mannerheim, 

and Medetera aldrichii Wheeler; and the parasitoid Coeloides 

dendroctoni Cushman. 

http://en.wikipedia.org/wiki/Mountain_pine_beetle; Wikipedia article, 

including comments on implications of current massive outbreak in 

Canada.

http://www.ext.colostate.edu/pubs/insect/05528.html; factsheet of 

Colorado State University.

http://forestry.nv.gov/forestry-resources/forest-health/mountain-pinebeetle/; Nevada Division of Forestry.

http://www.fs.fed.us/r6/nr/fid/fidls/fidl-2.pdf; USDA Forest Service 

Forest Pest and Disease Leaflet #2. 2009 revision; provides updated, 

more detailed distribution map.

http://www.usu.edu/beetle; USDA Forest Service, Rocky Mountain 

Research Station, Western Bark Beetles website including literature.

Safranyik, L., A.L. Carroll, and B. Wilson. 2006. The biology and 

epidemiology of the mountain pine beetle in lodgepole pine, p. 3-66. 

In: Safraynyik, L. and W.R. Wilson (eds.). The Mountain Pine Beetle: 

A synthesis of the biology, management and impacts on lodgepole pine.

Natural Resources Canada, Canadian Forest Service, Pacific Centre, 

Victoria, British Columbia: 304 p.

Robertson, C., T.A. Nelson, D.E. Jelinski, M.A. Wulder, and B. Boots. 

2009. Spatial-temporal analysis of species range expansion: the case 

of the mountain pine beetle, Dendroctonus ponderosae. Journal of 

Biogeography 36(8): 1446-1453. 

Web Links for Information 

on Mountain Pine Beetle

Articles
220 Forest Pest Insects in North America:

67. Douglas-fir Beetle, Dendroctonus pseudotsugae Hopkins (Coleoptera: 

Curculionidae, Scolytinae) 

Orientation to Pest Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, a native 

North American bark beetle, is the most important pest of Douglas-fir 

(Pseudotsuga menziesii [Mirbel] Franco) in western North America 

and the only bark beetle attacking this important timber species. Like 

many bark beetles, this species often persists at low levels, breeding 

primarily in felled, injured or diseased trees and doing little damage to 

any particular stand. However, at times populations develop that are able 

to kill even healthy trees, over large areas. Such outbreaks may develop 

after extensive wind damage, droughts, or large fires that greatly increase 

the number of susceptible trees. The signs of this bark beetle include 

reddish or yellowish boring dust caught in bark crevices. Live trees may 

respond to attack with abundant resin flow. A male and female beetle 

work together to dig an oviposition gallery, where the female lays her 

eggs, which are deposited in groups (10-36), spaced out at intervals along 

the oviposition gallery. Larval dig feeding galleries that diverge from the 

oviposition gallery in groups that resemble fans. Larvae pupate in cells 

constructed at the ends of the larval galleries. The Douglas-fir beetle 

has one generation per year. The insect mostly overwinters as adults, 

but with some large larvae present as well. Adult emergence from the 

wood occurs from April to June, depending on location and altitude, and 

newly emerged beetles attack new trees in July and August. In coastal 

areas, host tree resistance is usually adequate to check population growth 

of this species. But in inland areas, where trees are subject to greater 

environmental stress, outbreaks are more common.

The only breeding host of this beetle is Douglas fir (P. menziesii). 

Douglas-fir beetle is found throughout the range of its principal host in 

the western United States, Mexico, and Canada. 

Hosts Commonly Attacked

Distribution

Images of 

Douglas-fir Beetle

Figure 1. Pair of 

adult Douglas-fir 

beetles, Dendroctonus 

pseudotsugae, inside 

gallery. (Constance Mehmel, 

USDA Forest Service, 

Bugwood.org)
A Photographic Guide 221

Images of Douglas-fir 

Beetle (continued)

Figure 2. Larvae of Douglas-fir beetle in their galleries. (Left: Scott Tunnock, 

USDA Forest Service, Bugwood.org; right: Malcolm Furniss, Bugwood.org)

Figure 3. Red boring dust (left) and resin flow (right) on the bark of a Douglas-fir 

produced by adult Douglas-fir beetles. (Left: Doug Page, USDI Bureau of Land 

Management, Bugwood.org; right: Constance Mehmel, USDA Forest Service, 

Bugwood.org)

Figure 4. Galleries of Douglas-fir beetles. (Left: USDA Forest Service - Ogden 

Archive, USDA Forest Service, Bugwood.org; right: Kenneth E. Gibson, USDA 

Forest Service, Bugwood.org)
222 Forest Pest Insects in North America:

Images of Douglas-fir 

Beetle (continued)

Figure 5. Douglas-fir killed by Douglas-fir beetle. (A. Steven Munson, USDA

Forest Service, Bugwood.org)

Figure 6. Adult of 

Enoclerus sphegeus 

Fabricus. (Brytten 

Steed, USDA Forest 

Service, Bugwood.org)

Figure 7. The braconid 

parasitoid, Coeloides 

vancouverensis (Dalla 

Torre), ovipositing 

through shaved 

Douglas-fir bark onto 

Douglas-fir beetle 

larvae. (Roger Ryan, 

USFS PNW Station, 

Bugwood.org)
A Photographic Guide 223

Among the important natural enemies of the Douglas-fir beetle are 

Enoclerus sphegeus Fabricius, Thanasimus undatulus Say, Temnochila 

chlorodia Mannerheim, Coeloides brunneri Viereck, and Medetera 

aldrichii Wheeler. 

http://www.forestry.ubc.ca/fetch21/FRST308/lab6/dendroctonus_

pseudotsugae/douglas.html; fact sheet of the University of British 

Columbia.

http://www.forestpests.org/acrobat/fidl5.pdf; fact sheet of the USDA 

Forest Service, Insect pest and disease leaflet #5.

Furniss, M.M. 1979. An annotated bibliography of the Douglas-fir beetle 

(Dendroctonus pseudotsugae Hopkins). USDA Forest Service General 

Technical Report (INT-48): 40 p. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Douglas-fir Beetle

Articles
224 Forest Pest Insects in North America:

68. Engraver Beetle, Ips typographus (L.) (Coleoptera: Curculionidae, 

Scolytinae) 

Orientation to Pest The engraver beetle, Ips typographus (L.), is native to Europe and 

has not yet invaded North America, but is a species of concern as a 

potentially serious pest of spruce (Picea). It is also referred to as the 

European spruce bark beetle. This species is the most damaging bark 

beetle in Europe, and historically many widespread infestations of long 

duration have occurred. As with many bark beetles, attack on living trees 

is facilitated by chemically coordinated mass attack and the vectoring 

of a tree-killing fungus, in this case Ceratocystis polonica Siem. The 

biology and life cycle of the insect is typical of bark beetles. Females 

dig oviposition galleries and deposit eggs along their length. Larvae then 

dig feeding galleries at right angles to the oviposition gallery, creating 

a fan-like appearance. Larvae pupate in chambers at the ends of larval 

galleries. Outbreaks are apparently initiated by events or conditions 

that increase quickly the number of stressed or dead trees available as 

breeding sites. Storms, drought, and logging (which increases the number 

of wind-thrown trees subsequently) have all been suggested as factors 

able to stimulate outbreaks. It has been suggested that natural enemies 

do not control low density populations, and that the regulatory factor is 

mortality from competition among larvae when breeding trees are scarce. 

However, other authors find that natural enemies cause up to 82 percent 

mortality to brood, suggesting they may indeed be important. Damage 

may be reduced by prompt removal of recently attacked trees because as 

many as 80 percent of parent beetles start a “sister brood” within weeks. 

Mass trapping with a synthetic pheromone blend is also employed. 

This beetle attacks spruces (Picea), such as Norway spruce (Picea abies

[L.] H. Karst.). 

Engraver beetles are found throughout much of central Europe, 

Scandinavia, and east into Russia, northeastern China, Korea, and Japan. 

Hosts Commonly Attacked

Distribution

Figure 1. Adults of the engraver beetle, Ips typographus (left: light brown, young 

adults; right: fully darkened, mature specimen). (Left: Bjørn Økland, Norwegian 

Forest Research Institute, Bugwood.org; right: Maja Jurc, University of Ljubljana, 

Bugwood.org)

Images of 

Engraver Beetle
A Photographic Guide 225

Images of Engraver 

Beetle (continued)

Figure 2. Close-up of 

one egg of the engraver 

beetle. (Daniel Adam, 

Office National des 

Forêts, Bugwood.org)

Figure 3. Larvae of engraver beetle (in a medium density infestation). 

(Left: SRPV, Limoges Archive, Les Services Régionaux de la Protection des 

Végétaux, Bugwood.org; center: Louis-Michel Nageleisen, Département de la 

Santé des Forêts, Bugwood.org; right: Daniel Adam, Office National des Forêts, 

Bugwood.org)
226 Forest Pest Insects in North America:

Images of Engraver 

Beetle (continued)

Figure 4. Pupae (left) of the engraver beetle in chambers at tips of larval 

galleries (in a low density infestation); right, close up of one pupa. (Left: Daniela 

Lupastean, University of Suceava, Bugwood.org; right: Maja Jurc, University of 

Ljubljana, Bugwood.org)

Figure 5. Galleries of engraver beetles: left, adults cutting oviposition galleries; 

right, finished larval galleries branching off oviposition gallery with pupation 

chambers at tips. (Both photos: Milan Zubrik, Forest Research Institute - 

Slovakia, Bugwood.org)

Figure 6. Spruce trees in Slovakia killed by the engraver beetle. (Milan Zubrik, 

Forest Research Institute - Slovakia, Bugwood.org)
A Photographic Guide 227

Images of Engraver 

Beetle (continued)

Figure 7. Traps used to detect engraver beetles (left) or for mass trapping (right, 

in logged area). (Both photos: Milan Zubrik, Forest Research Institute - Slovakia, 

Bugwood.org)

Figure 8. Left, larva of external parasitoid on larva of engraver beetle; right, 

multiple cocoons of ichneumonid parasitoid formed in larval galleries of engraver 

beetle. (Also visible in photo on right in upper and lower areas are the galleries 

of the smaller, very common European species, Pityogenes chalcographus [L.]). 

(Left: Gyorgy Csoka, Hungary Forest Research Institute, Bugwood.org; right: 

Petr Kapitola, State Phytosanitary Administration, Bugwood.org)

Figure 9. Larva of the long-legged fly Medetera signaticornis Loew, a 

specialized predator of bark beetle larvae, known only from Ips typographus, 

usually in high abundance in Western Europe. (Jiri Hulcr, Michigan State 

University, Bugwood.org)
228 Forest Pest Insects in North America:

Images of Engraver 

Beetle (continued)

Figure 10. The red-bellied clerid beetle, Thanasimus formicarius (L.), is an 

important predator of the engraver beetle in Europe (left, adult; right, larva). 

(Left: Scott Bauer, USDA Agricultural Research Service, Bugwood.org; right: 

Daniela Lupastean, University of Suceava, Bugwood.org)

The natural enemies of the engraver beetle have been reported from 

many locations and a large number of species of parasitoids and 

predators have been observed. Among the commonly reported species 

are the red-bellied clerid beetle (Thanasimus formicarius [L.]), the 

long-legged fly Medetera signaticornis Loew, and various braconid and 

ichneumonid parasitoids. See the review by Mills and Schlup (1989).

http://www.barkbeetles.org/exotic/htypgrph.html; fact sheet describes 

characters for species recognition. 

http://www.fs.fed.us/foresthealth/technology/invasives_ipstypographus_

riskmaps.shtml; USDA website that describes forests in the United States 

at potential risk from this bark beetle.

http://www.issg.org/database/species/ecology.asp?si=1441&fr=1&sts

=&lang=EN; factsheet of the Global Invasive Species Database, with 

information on biology and method of movement between countries.

Mills, N.J. and M. Schlup. 1989. The natural enemies of Ips typographus

in central Europe: Impact and potential use in biological control. In: 

Kulhavy, D.L. and M.C. Miller (eds.). Potential for Biological Control 

of Dendroctonus and Ips Bark Beetles. Published by the Center for 

Applied Studies, School of Forestry, Stephen F. Austin State University, 

Nacogdoches, Texas, USA: 131-146.

Wermelinger, B. 2004. Ecology and management of the spruce bark 

beetle Ips typographus – a review of recent research. Forest Ecology and 

Management 202(1/3): 67-82.

Grégoire, J.-C. and H.F. Evans. 2004. Damage and control of Bawbilt 

organisms - an overview, pp. 19-37. In: Lieutier, F., K.R. Day, A. Battisti, 

J.-C. Grégoire, and H.F. Evans (eds.). Bark and Wood Boring Insects in 

Living Trees in Europe, a Synthesis. Springer, Netherlands. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Engraver Beetle

Articles
A Photographic Guide 229

69. Pine Engraver Beetle, Ips pini (Say) (Coleoptera: Curculionidae 

[formerly Scolytidae])

The pine engraver beetle, Ips pini (Say), is a native bark beetle with a 

very wide distribution in North America. In natural forests, this species 

is of little importance and is mainly associated with smaller diameter 

(12-20 cm) pine or spruce trees that are dying or have been recently 

killed by storms or logging. Under these conditions the species is 

beneficial and contributes to recycling of stressed or dying trees. Its 

numbers may increase when logging, thinning, or storms increase the 

amount of breeding material that is locally available. When this happens, 

healthy trees in the area may also be attacked. This species is considered 

the most important bark beetle attacking red pine (Pinus resinosa Sol. 

ex Aiton) in the Great Lakes states of the USA. Male beetles bore into 

trees and create a nuptial chamber. Each male produces pheromones 

that attract multiple females of the same species. After mating, 3 to 6 

females construct oviposition galleries in the inner bark that radiate out 

from the nuptial chamber in a “Y” or “H” shaped pattern. Larval galleries 

branch off the oviposition galleries, and pupation takes place in cells at 

the end of the larval galleries. Pine engraver beetles can vector a blue 

stain fungus, which aids the beetle in killing the host tree by clogging 

the water-transporting elements in the tree. Symptoms and signs of pine 

engraver attack are essentially the same as those of many bark beetles, 

including yellow, red, and brown foliage of dying trees, together with 

boring dust and pitch tubes on the bark. Commonly, there are 3 to 4 

generations per year. 

Ips pini breeds in all the species of pines and spruce in its range and 

is of greatest concern in lodgepole (P. contorta Douglas), ponderosa 

(P. ponderosa Douglas ex C. Lawson), Jeffrey (P. jeffreyi Balf.), and red 

(P. resinosa) pines. 

The pine engraver is found from northern Canada and Alaska to northern 

Mexico. It occurs throughout most of the coniferous forests of North 

America except the Pacific Coastal forests, the southern pine forests, and 

Mexico. In the eastern United States, it is widespread in the north and 

extends along the Appalachian Mountains south to Georgia. 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Figure 1. Adult of pine 

engraver beetle, Ips 

pini. (Pennsylvania 

Department of 

Conservation and 

Natural Resources 

- Forestry Archive, 

Bugwood.org)

Images of 

Pine Engraver Beetle
230 Forest Pest Insects in North America:

Images of Pine Engraver 

Beetle (continued)

Figure 2. Nuptial 

chamber with five 

oviposition galleries 

branching off, with 

females in galleries at 2 

and 10 o’ clock. (Scott 

Tunnock, USDA Forest 

Service, Bugwood.org)

Figure 3. Larval galleries of the pine engraver projecting at right angles to the 

oviposition galleries. (USDA Forest Service - Region 6 - Pacific Northwest 

Archive, USDA Forest Service, Bugwood.org)

Figure 4. Frass ejected from bore holes by adult pine engravers. (Brytten Steed, 

USDA Forest Service, Bugwood.org)
A Photographic Guide 231

Images of Pine Engraver 

Beetle (continued)

Figure 5. Adult 

emergence holes of 

pine engraver beetles. 

(Steven Katovich, 

USDA Forest Service, 

Bugwood.org)

Figure 6. Lundgren 

funnel trap used to 

detect pine engraver 

beetles at a slash 

pile. (Brytten Steed, 

USDA Forest Service, 

Bugwood.org)
232 Forest Pest Insects in North America:

Images of Pine Engraver 

Beetle (continued)

Figure 8. Larva (left) and adult (right) of Thanasimus dubius, a common 

predator of the pine engraver beetle. (Left: Gerald J. Lenhard, Louiana State 

Univ, Bugwood.org; right: USDA Forest Service Archive, USDA Forest Service, 

Bugwood.org)

Figure 9. Larva (left) and adult (right) of Enoclerus sphegeus, a common predator 

of the pine engraver beetle. (Left: USDA Forest Service - Region 2 - Rocky 

Mountain Region Archive, USDA Forest Service, Bugwood.org; right: Brytten 

Steed, USDA Forest Service, Bugwood.org)

Figure 7. Group of red 

pines (Pinus resinosa

Soland.) in Minnesota 

killed by pine engraver 

beetle. (Steven 

Katovich, USDA Forest 

Service, Bugwood.org)
A Photographic Guide 233

The natural enemies of the pine engraver beetle are similar to those 

of many bark beetles and include several predatory clerids, such as 

Thanasimus dubius (Fabricius) and Enoclerus sphegeus (Fabricius), as 

well as such parasitoids as the braconid Coeloides dendroctoni Cushman 

and the pteromalids Pachyceras xylophagorum Ratz., Rhopalicus 

pulchripennis (Crawford), and Tomicobia tibialis Ashmead.

http://wiki.bugwood.org/Ips_pini; a Bugwiki fact sheet on Ips pini.

http://www.fs.fed.us/r6/nr/fid/fidls/f122.htm; a USDA Forest Service 

Forest and Insect Disease Leaflet: Gibson, K.E., Kegley, S.J., and 

Livingston R.L. 1997. Pine Engraver, Ips pini, in the Western United 

States. Forest Insect and Disease Leaflet No. 122. USDA Forest Service. 

http://www.ext.colostate.edu/pubs/insect/05558.html; perspective on 

other species of Ips (11 species in Colorado, featured on this website).

Erbilgin, N., E.V. Nordheim, B.H. Aukema, and K.F. Raffa. 2002. 

Population dynamics of Ips pini and Ips grandicollis in red pine 

plantations in Wisconsin: within- and between-year associations with 

predators, competitors, and habitat quality. Environmental Entomology

31: 1043-1051.

Dahlsten, D.L., D.L. Six, N. Erbilgin, K.F. Raffa, A.B. Lawson, and 

D.L. Rowney. 2003. Attraction of Ips pini (Coleoptera: Scolytidae) and 

its predators to various enantiomeric ratios of ipsdienol and lanierone in 

California: Implications for the augmentation and conservation of natural 

enemies. Environmental Entomology 32: 1115-1122. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Pine Engraver Beetle

Articles
234 Forest Pest Insects in North America:

70. Southern Pine Engraver, Ips grandicollis (Eichhoff) (Coleoptera: 

Curculionidae, Scolytinae) 

Orientation to Pest The southern pine engraver (also called the eastern five-spined Ips), 

Ips grandicollis (Eichhoff), is a native bark beetle that occurs in the 

eastern parts of Canada and the United States, in Central America, and 

on some Caribbean islands. It is also invasive in Australia, where it is a 

pest of plantations of Monterey pine (Pinus radiata D. Don). The elytra 

(hardened forewings) end in a scoped out area with typically 5 teeth on 

each side. It breeds most often in recently felled trees and logging slash, 

but can also breed in limbs and trunks of live trees that are under attack 

by other bark beetle species. Most breeding occurs in limbs and the upper 

crown. Drought and logging both can potentially stimulate outbreaks of 

this species, causing small infestations to expand in area. The biology 

of this species is similar to that of Ips pini (Say). Male beetles create a 

nuptial chamber beneath the bark and produce pheromones that attract 

multiple females. After mating, the females construct 3 to 5 oviposition 

galleries that branch off from the nuptial chamber. The parent galleries 

are kept free of boring dust, unlike those of the southern pine beetle 

(Dendroctonus frontalis Zimmermann). Larval galleries branch off the 

oviposition galleries and are usually run horizontally across the tree 

trunk. Pine engraver beetles can vector a blue stain fungus, which aids 

the beetle in killing the host tree by clogging the water-transporting 

elements in the tree. Symptoms and signs of pine engraver attack are 

essentially the same as those of many bark beetles, including the yellow, 

red or brown foliage characteristic of dying trees, together with boring 

dust and pitch tubes on the bark. There are six or more generations per 

year in the southern United States.

Ips grandicollis breeds in most of the pine species in the southern United 

States. North of the southern pines region, this species is principally 

found associated with pitch pine (Pinus rigida Mill.). 

The southern pine engraver is found in eastern Canada and in the eastern 

United States from Massachusetts west to Minnesota, Nebraska and 

Texas, and throughout the southern states. 

Hosts Commonly Attacked

Distribution
A Photographic Guide 235

Images of 

Southern Pine Engraver

Figure 1. Adult of southern pine engraver, Ips grandicollis. Right, see the scoped 

out area of the fore wings and the surrounding teeth. (Both photos: Pest and 

Diseases Image Library, Bugwood.org)

Figure 2. Comparative size of southern pine engraver (Ips grandicollis) relative 

to other southern pine bark beetles. (John L. Foltz, University of Florida, 

Bugwood.org)

Figure 3. Egg of southern pine engraver. (Lacy L. Hyche, Auburn University, 

Bugwood.org)
236 Forest Pest Insects in North America:

Images of Southern Pine 

Engraver (continued)

Figure 4. Callow adult (left), larva (middle), and pupa (right) of southern pine 

engraver. (Roger Anderson, Duke University, Bugwood.org)

Figure 5. Left, nuptial chambers (see arrows) of southern pine engraver, with 

five and four oviposition galleries branching off; right, larval galleries branching 

off oviposition galleries, with pupation cells at end of each gallery. (Left: 

Jeffrey Eickwort, Florida Department of Agriculture and Consumer Services, 

Bugwood.org; right: Texas Forest Service Archive, Texas Forest Service, 

Bugwood.org)

Figure 6. Group of 

Monterey pines (P. 

radiata) in Australia, 

killed by southern pine 

engraver. (Dennis 

Haugen, Bugwood.org)
A Photographic Guide 237

Images of Southern Pine 

Engraver (continued)

Figure 7. The predatory 

checkered beetle 

Thanasimus dubius is a 

common predator of the 

southern pine engraver. 

(USDA Forest Service 

Archive, USDA Forest 

Service, Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

The natural enemies of the southern pine engraver include the predatory 

clerid Thanasimus dubius (Fabricius), the predatory trogositid beetle 

Temnochila virescens (Fabricius), as well as various parasitoids, 

including Roptrocerus xylophagorum Ratzeburg. Thanasimus dubius and 

Temnochila virescens have been introduced into Australia against this 

bark beetle.

http://www.na.fs.fed.us/spfo/pubs/fidls/ips/ipsfidl.htm; a USDA Forest 

Service leaflet on Ips pine bark beetles in the southern USA, comparing 

several species, including I. grandicollis.

http://www.eppo.org/QUARANTINE/insects/Ips_grandicollis/IPSXGR_

ds.pdf; EPPO data sheet on Ips grandicollis.

Foltz, J.L., E.P. Merkel, and R.C. Wilkinson. 1984. Annotated 

bibliography of Dendroctonus terebrans (Oliver), Ips avulsus (Eichhoff), 

Ips grandicollis (Germar) in the southeastern USA. Monograph #12, 

Agricultural Experiment Station, University of Florida: 47 p.

Lawson, S.A. and F.D. Morgan. 1992. Rearing of two predators, 

Thanasimus dubius and Temnochila virescens, for the biological control 

of Ips grandicollis in Australia. Entomologia Experimentalis et Applicata

65: 225-233.

Abbott, I. 1993. Review of the ecology and control of the introduced 

bark beetle Ips grandicollis in Western Australia, 1952-1990. 

CALMScience 1: 35-46. 

Web Links for Information 

on Southern Pine Engraver

Articles
238 Forest Pest Insects in North America:

71. Six-spined Ips, Ips calligraphus (Germar) (Coleoptera: Curculionidae, 

Scolytinae)

Orientation to Pest The six-spined Ips, Ips calligraphus (Germar), is a native bark beetle 

found in both the eastern and western United States. Two subspecies 

of I. calligraphus are recognized that occur in the United States. Ips 

calligraphus ponderosae is found attacking ponderosa pine (Pinus 

ponderosa Douglas ex C. Lawson) in the Black Hills of South Dakota, 

the eastern Rocky Mountains, and the northern Sierra Madre Oriental 

of Mexico. Ips calligraphus calligraphus is found in the eastern 

United States and California (where it likely was introduced from the 

eastern United States). The subspecies found in the eastern United 

States may attack all species of southern pines, including pitch pine 

(P. rigida Millar). The eastern and western subspecies of I. calligraphus

breed in trees that have been felled, are dying, under drought stress, or 

attack from other bark beetles. Trunks, stumps, and large limbs may 

be attacked. Trunks of apparently healthy pines may sometimes be 

attacked, especially in concert with other Ips or Dendroctonus species. 

In the southern United States, this is one of the first species to attack 

drought-stressed trees. Infestations may consist of scattered trees or fairly 

large groups of trees, particularly during periods of drought. In general, 

however, infestations of Ips species do not expand continuously as is 

typical of southern pine beetle (Dendroctonus frontalis Zimmermann) 

infestations. In the western United States, this species is most often 

found in the thick-barked portion of the boles of ponderosa pines. Male 

beetles construct a nuptial chamber where they attract and mate with two 

to six females. The females then dig individual oviposition galleries that 

radiate out from the nuptial chamber and are oriented vertically along the 

trunk. Larval galleries are broad, long, and winding, and typically run 

horizontally across the trunk. In the southern United States there are up 

to 6 or more generations per year. In California, there are typically four 

generations per year. 

Ips calligraphus in the eastern United States may attack all native pine 

species, but is found most commonly in loblolly (P. taeda L.), slash 

(P. elliotii Engelm.), shortleaf (P. echinata Mill.), longleaf (P. palustris

Mill.), and pitch (P. rigida) pine. In the western United States, the 

principal host is ponderosa pine (P. ponderosa). 

The six-spined Ips subspecies found in the eastern United States occurs 

from Florida, north to Massachusetts, and west to Minnesota and eastern 

Texas. The western subspecies is found in Montana and South Dakotas, 

south along the eastern Rocky Mountains. 

Hosts Commonly Attacked

Distribution
A Photographic Guide 239

Images of 

Six-spined Ips

Figure 1. Adult of six-spined Ips, Ips calligraphus, the largest of the southern U.S. 

Ips species. (Left: David T. Almquist, University of Florida, Bugwood.org; right: 

John L. Foltz, University of Florida, Bugwood.org)

Figure. 2. The six teeth 

found at the end of the 

depressed area at the 

end of the body are 

diagnostic for six-spined 

Ips populations (see 

discussion of subspecies 

in Orientation to Pest 

section). (J.R. Baker 

and S.B. Bambara, 

North Carolina 

State University, 

Bugwood.org)

Figure 3. Eggs of six-spined Ips. (Lacy L. Hyche, Auburn University, 

Bugwood.org)
240 Forest Pest Insects in North America:

Images of Six-spined Ips

(continued)

Figure 4. Pupae of six-spined Ips. (Lacy L. Hyche, Auburn University, 

Bugwood.org)

Figure 5. Nuptial 

chamber (at tip of pen) 

of the six-spined Ips, 

with four oviposition 

galleries. (Ronald F. 

Billings, Texas Forest 

Service, Bugwood.org)
A Photographic Guide 241

Images of Six-spined Ips

(continued)

Figure 6. Larval 

galleries branching 

off the oviposition 

galleries (vertical) of 

six-spined Ips. 

(William M. Ciesla, 

Forest Health 

Management 

International, 

Bugwood.org)

Figure 7. Small pitch tube made by six-spined Ips. (G. Keith Douce, University of 

Georgia, Bugwood.org)
242 Forest Pest Insects in North America:

The natural enemies of the six-spined Ips include Thanasimus dubius

(Fabricius), Temnochila virescens (Fabricius), and Medetera spp., 

species that prey on a variety of Ips and Dendroctonus bark beetles. 

Woodpeckers (Picidae), including the endangered red-cockaded 

woodpecker (Picoides borealis), also may destroy I. calligraphus broods. 

The impact of woodpecker feeding on infested trees is greatest during 

winter months, when few other sources of food are available.

http://www.barkbeetles.info/index.php; technical information on 

recognition, distribution and biology of bark beetles, especially those 

of the southern United States and Mexico.

http://www.na.fs.fed.us/spfo/pubs/fidls/ips/ipsfidl.htm; USDA Forest 

Service Pest and Disease Leaflet No. 129 “Ips bark beetles in the South”.

http://entnemdept.ufl.edu/creatures/trees/beetles/ips_beetles.htm; fact 

sheet of the University of Florida covering various species of Ips bark 

beetles.

Wilkinson, R.C. and J.L. Foltz. 1980. A selected bibliography 

(1959-1979) of three southeastern species of Ips engraver beetles. 

Bulletin of the Entomological Society of America 26: 375-380.

Conner, M.D. and R.C. Wilkinson. 1983. Ips bark beetles in the 

South. Forest Insect and Disease Leaflet No.129. U.S. Department of 

Agriculture, Forest Service. 12 p.

Miller, M.C. 1984. Mortality contribution of insect natural enemies 

to successive generations of Ips calligraphus (Germar) (Coleoptera, 

Scolytidae) in loblolly pine. Zeitschrift für Angewandte Entomologie

98(5): 495-500.

Lanier, G.N., S.A. Teale, and J.A. Pajares. 1991. Biosystematics of the 

genus Ips (Coleoptera: Scolytidae) in North America: review of the Ips 

calligraphus group. The Canadian Entomologist 123: 1103-1124.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Six-spined Ips

Articles
A Photographic Guide 243

72. Small Southern Pine Engraver, Ips avulsus Eichhoff (Coleoptera: 

Curculionidae, Scolytinae) 

Orientation to Pest The small southern pine engraver, Ips avulsus Eichhoff, is a native North 

American bark beetle found throughout the eastern United States. It is 

the smallest of the various species in this genus that breed in eastern 

pines. Attacks are concentrated on sections of trees with thin-bark, such 

as young pines or the limbs and tops of older trees. Attacks may occur 

in young trees and the tops of large living trees, which may be killed. 

However, when large living trees are attacked, the infestation is usually 

limited to the upper crown, and the mid- and lower boles of the same 

tree are often colonized by other species of Ips (Ips calligraphus Germar, 

Ips grandicollis Eichhoff, or the southern pine beetle [Dendroctonus 

frontalis Zimmermann]). Any tree cutting or accidental injury that creates 

a pitch flow can induce attack by this species. Adults are very small 

(2-3 mm) and the tip of the abdomen (the depressed area) is shallow, 

with deep knobs and four small teeth on each margin. Males create a 

nuptial chamber and produce a pheromone that attracts one or more 

females. After mating, each female constructs a linear oviposition gallery 

in the inner bark that parallels the grain of the wood. Larval galleries are 

short and transverse, and each ends in a pupal cell in the phloem when 

the larva completes development. Pine engraver beetles can vector a blue 

stain fungus, which aids the beetle in killing the host tree by clogging 

the water-transporting elements in the tree. Symptoms and signs of pine 

engraver attack are essentially the same as those of many bark beetles, 

including the yellow, red, or brown foliage characteristic of dying trees, 

together with boring dust and pitch tubes on the bark. In the southern 

United States, there may up to 10 or more generations per year.

Ips avulsus breeds in various southern pines, including eastern white 

(Pinus strobus L.), loblolly (P. taeda L.), longleaf (P. palustris Miller), 

pitch (P. rigida Miller), pond (P. serotina Michx.), sand (P. clausa

[Chapm. ex Engelm.] Sarg.), shortleaf (P. echinata Miller), slash 

(P. elliottii Engelm.), and Virginia (P. virginiana Miller) pines.

The small southern pine engraver occurs from Pennsylvania to Florida 

and west to Texas.

Hosts Commonly Attacked

Distribution
244 Forest Pest Insects in North America:

Images of Small

Southern Pine Engraver

Figure 1. Adult (left) of the small southern pine engraver, Ips avulsus, which is 

the smallest of the eastern Ips species, as seen in relation to the other southern 

pine bark beetle species (right). (Left: J.R. Baker and S.B. Bambara, North 

Carolina State University, Bugwood.org; right: John L. Foltz, University of Florida, 

Bugwood.org)

Figure 3. The pitch tube of the small southern pine engraver (center of photo, 

small). (David J. Moorhead, University of Georgia, Bugwood.org)

Figure 2. The depressed 

region at the posterior 

of the small southern 

pine engraver is shallow, 

with strong knobs on its 

surface and four teeth 

along each side. (J.R. 

Baker and S.B. Bambara, 

North Carolina State 

University, Bugwood.org)
A Photographic Guide 245

Images of Small Southern

Pine Engraver (continued)

Figure 4. A pair of small southern pine engraver beetles in their nuptial chamber, 

showing associated oviposition galleries. (Erich G. Vallery, USDA Forest Service 

- SRS-4552, Bugwood.org)

Figure 5. Short 

galleries made by 

larvae radiating out 

from linear oviposition 

galleries of the small 

southern pine engraver. 

(Jeffrey Eickwort, 

Florida Department 

of Agriculture and 

Consumer Services, 

Bugwood.org)

Figure 6. Galleries, pupae, and larvae of the small southern pine engraver. 

(Ronald F. Billings, Texas Forest Service, Bugwood.org)
246 Forest Pest Insects in North America:

Images of Small Southern

Pine Engraver (continued)

Figure 7. Pupal cells of small southern pine engraver give a paddle-like 

appearance to the larval galleries. (Robert L. Anderson, USDA Forest Service, 

Bugwood.org)

Figure 8. Attacks of the 

small southern pine 

engraver on larger trees 

are concentrated in 

the tops of trees (here, 

a loblolly pine [Pinus 

taeda]). (Ronald F. 

Billings, Texas Forest 

Service, Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

The natural enemies of the small southern pine engraver have not been 

reported but likely are similar to those of other Ips species.
A Photographic Guide 247

http://www.na.fs.fed.us/spfo/pubs/fidls/ips/ipsfidl.htm; a fact sheet on 

southern Ips in general; gives list of host trees and map of range by Ips

species.

http://edis.ifas.ufl.edu/in701; a University of Florida fact sheet on various 

southern Ips species.

Foltz, J.L., E.P. Merkel, and R.C. Wilkinson. 1984. Annotated 

bibliography of Dendroctonus terebrans (Oliver), Ips avulsus (Eichhoff), 

Ips grandicollis (Germar) in the southeastern USA. Monograph #12, 

Agricultural Experiment Station, University of Florida: 47 p.

Birch, M.C., P. Svihra, T.D. Paine, and J.C. Miller. 1980. Influence 

of chemically mediated behavior on host tree colonization by four 

cohabiting species of bark beetles. Journal of Chemical Ecology 6: 

395-414.

Web Links for Information 

on Small Southern 

Pine Engraver

Articles
248 Forest Pest Insects in North America:

73. Silver Fir Beetle, Pseudohylesinus sericeus (Mannerheim) (Coleoptera: 

Curculionidae, Scolytinae) 

Orientation to Pest The silver fir beetle, Pseudohylesinus sericeus (Mannerheim), is a minor 

pest that attacks windthrown, felled, injured, and severely suppressed 

trees. The damage it causes is rarely important. However, in the 1940s 

and 1950s, large outbreaks occurred on Pacific silver fir (Abies amabilis

Douglas ex J.Forbes) in the Pacific Northwest of the United States. In 

Oregon, there is one generation per year, but in Washington, a generation 

requires two years. The egg gallery is transverse. In large trees, attacks 

occur in the upper bole and limbs. The beetle often attacks trees that 

are infected with brown-stain or root-rotting fungi such as Armillaria

sp., Heterobasidion annosum (Fr.) Bref., and Phellinus weirii (Murrill) 

Gilbert.

The principal hosts of the silver fir beetle are various fir (Abies), western 

hemlock (Tsuga heterophylla [Raf.] Sarg.), and Douglas-fir (Pseudotsuga 

menziesii [Mirb.] Franco).

The silver fir beetle ranges principally from British Columbia to 

California and eastward to northern Idaho. It also may occur in southeast 

Alaska and western Montana.

Hosts Commonly Attacked

Distribution

Figure 1. Adult of 

Pseudohylesinus sp. 

(Province of British 

Columbia, Minstry of 

Forests and Range, 

Forest Practices Branch)

Image of 

Silver Fir Beetle
A Photographic Guide 249

The natural enemies of silver fir beetle are unknown.

http://www.for.gov.bc.ca/hfp/publications/00198/silver_fir_beetle.htm; 

fact sheet of the forestry department of the province of British Columbia, 

Canada.

http://www.fs.fed.us/r6/nr/fid/fidls/fidl-60.pdf; USDA Forest Service pest 

leaflet on silver fir beetle.

Gara, R.I. 1982. Insect pests of true firs in the Pacific Northwest. In: 

Oliver, C.D. and R.M. Kenady (eds.). Proceedings of the biology and 

management of true fir in the Pacific Northwest. Seattle-Tacoma, 

Washington, February 24-26, 1981. Contribution, Institute of Forest 

Resources, University of Washington (45): 157-160.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Silver Fir Beetle

Articles
250 Forest Pest Insects in North America:

74. Fir Engraver, Scolytus ventralis LeConte (Coleoptera: Curculionidae, 

Scolytinae) 

Orientation to Pest The fir engraver, Scolytus ventralis LeConte, is a pest of true firs in 

western North America. Adults are about 4.0 mm long, making this 

one of the largest species in the genus Scolytus. The egg galleries dug 

by females are transverse to the trunk and galleries are deep enough to 

deeply score the wood, especially close to the nuptial chamber. Eggs 

are laid along the oviposition galleries, from which larvae dig lateral 

galleries up or down the trunk after hatching. Pupation occurs in the 

inner bark at the end of the larval galleries. Fir engraver attacks trees 

of varying ages and transmits the brown-stain fungus Trichosporium 

symbioticum Wright, which is essential for successful brood 

development. Stressed trees that are infected with various fungi or that 

have been damaged by outbreaks of other insects are likely to be attacked 

by the fir engraver. Effects of this bark beetle vary, with some trees dying 

quickly, while others are just top-killed or recover, even from repeated 

attacks. There is one generation per year, or in some areas, only one in 

two years. In intensively managed areas, prompt removal or treatment 

of infested trees may help protect remaining trees for a time, but in most 

areas control is best achieved by trying to lower sources of stress and 

maintain high tree vigor. 

The principal hosts of the fir engraver are various species of fir (Abies), 

especially white (Abies concolor [Gordon] Lindley ex Hildebrand), grand 

(A. grandis [Douglas ex D. Don] Lindley), and red fir (A. magnifica

A. Murray). Occasionally Douglas-fir (Pseudotsuga menziesii [Mirbel] 

Franco), hemlock (Tsuga), or spruce (Picea) are attacked.

The fir engraver ranges from British Columbia to California, Wyoming, 

Colorado, Arizona, and New Mexico. 

Hosts Commonly Attacked

Distribution

Images of 

Fir Engraver

Figure 1. Adult of the 

fir engraver, Scolytus 

ventralis. (Donald Owen, 

California Department 

of Forestry and Fire 

Protection, 

Bugwood.org)
A Photographic Guide 251

Images of Fir Engraver

(continued)

Figure 2. Pitch 

streamers on trunk are 

a sign of attack on fir by 

the fir engraver. (Donald 

Owen, California 

Department of Forestry 

and Fire Protection, 

Bugwood.org)

Figure 3. Bubbled 

bark is a sign of 

previous fir engraver 

attacks survived by a 

tree. (Chris Schnepf, 

University of Idaho, 

Bugwood.org)
252 Forest Pest Insects in North America:

Images of Fir Engraver

(continued)

Figure 4. Galleries of the 

fir engraver. Note the 

horizontal oviposition 

gallery, with multiple 

larval galleries above 

and below. (Dave 

Holland, USDA Forest 

Service, Bugwood.org)

Figure 5. White fir (Abies concolor) killed by the fir engraver. (William M. Ciesla, 

Forest Health Management International, Bugwood.org)
A Photographic Guide 253

Images of Fir Engraver

(continued)

Figure 6. Top kill is 

a sign of attack of fir 

engraver on large, 

otherwise healthy, trees. 

(Kenneth E. Gibson, 

USDA Forest Service, 

Bugwood.org)

Figure 7. Damage at 

the stand level from the 

fir engraver. (A. Steven 

Munson, USDA Forest 

Service, Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

The natural enemies of fir engraver are relatively unstudied. 

http://forestry.nv.gov/forestry-resources/forest-health/fir-engraver-beetle/; 

Nevada Division of Forestry fact sheet.

www.oregon.gov/ODF/privateforests/docs/fh/FirEngraver.pdf?ga=t; 

Oregon Department of Forestry website.

http://www.fs.fed.us/r6/nr/fid/fidls/fidl-13.pdf; USDA Forest Service 

Forest Insect and Pest Leaflet on fir engraver.

Berryman, A.A. 1973. Population dynamics of the fir engraver, Scolytus 

ventralis (Coleoptera: Scolytidae). I. Analysis of population behavior 

and survival from 1964 to 1971. The Canadian Entomologist 105: 

1465-1488.

Web Links for Information 

on Fir Engraver

Articles
254 Forest Pest Insects in North America:

75. Columbian Timber Beetle, Corthylus columbianus Hopkins (Coleoptera: 

Curculionidae, Scolytinae) 

Orientation to Pest Columbian timber beetle, Corthylus columbianus Hopkins, is a native 

North American ambrosia beetle, one of a group of beetles that vector 

wood-destroying fungi, which the beetle larva then eats. Unlike most 

ambrosia beetles, Columbian timber beetles attack live trees rather than 

dead, dying, or newly felled trees. Trees, however, do not die, since trees 

are able to fill galleries with callus tissue. However, losses occur from 

lowered quality of timbers cut from infested trees, due to the presence of 

callus-filled galleries and fungal-stained wood. 

Columbian timber beetles attack a wide range of hardwoods, including 

various oaks (Quercus) and maples (Acer), sycamore (Platanus 

occidentalis L.), poplar (Populus), elm (Ulmus), beech (Fagus), and 

others.

The Columbian timber beetle ranges in the United States from 

Massachusetts to Georgia, west to Michigan and Missouri. 

Hosts Commonly Attacked

Distribution

Images of Columbian 

Timber Beetle

Figure 1. Callow adult (left) and pupae of the Columbian timber beetle, Corthylus 

columbianus. (Jack C. Nord, USDA Forest Service, Bugwood.org)
A Photographic Guide 255

Images of Columbian 

Timber Beetle (continued)

Figure 2. Egg of Columbian timber beetle in chamber prepared by adult. Note 

the ambrosia fungus (Ambrosiella eylebori Brader) coating the chamber, which 

is inoculated into the gallery by the adult. (Jack C. Nord, USDA Forest Service, 

Bugwood.org)

Figure 3. Galleries of Columbian timber beetle. (James Solomon, USDA Forest 

Service, Bugwood.org)
256 Forest Pest Insects in North America:

Images of Columbian 

Timber Beetle (continued)

Figure 4. Emergence holes and sap-soaked patches on trunk are signs of 

Columbian timber beetles. (Left: Jack C. Nord, USDA Forest Service, 

Bugwood.org; right: James Solomon, USDA Forest Service, Bugwood.org)

Figure 5. Milled maple timber shows the callus-filled galleries of Columbian 

timber beetle, and blue staining of associated ambrosia fungus. (Left: Jack C. 

Nord, USDA Forest Service, Bugwood.org; right: James Solomon, USDA Forest 

Service, Bugwood.org)

Natural enemies of Columbian timber beetle have not been reported.

http://wiki.bugwood.org/Archive:South/Corthylus_columbianus; 

Bugwiki fact sheet. 

Milne, D.H. and R.L. Giese. 1969. The Columbian timber beetle, 

Corthylus columbianus (Coleoptera: Scolytidae). IX. Population biology 

and gallery characteristics. Entomological News 80(9): 225-237.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Columbian Timber Beetle

Articles
A Photographic Guide 257

76. Ambrosia Beetles, Xyleborus spp. (Coleoptera: Curculionidae, Scolytinae) 

Orientation to Pests Xyleborus ambrosia beetles are a genus of wood-boring beetles that carry 

fungi that colonize their galleries and serve as food for their larvae. Other 

genera of beetles that have similar symbiotic relationships with fungi 

are also referred to as ambrosia beetles. The genus Xyleborus appears 

to be a collection of poorly related beetles that is in need of revision. As 

currently constructed, there are at least 17 species in the United States 

and Canada (16 in the eastern United States), mostly native but with 

several invasive species. Many of these species breed in both coniferous 

and deciduous trees and shrubs of all sizes. Trees preferred for attack 

are ones that are unhealthy, dying, or that have recently been wounded 

or felled. Dead areas in living trees can also be attacked. Because this 

group of beetles inoculate their larval galleries with wood-decay fungi, 

which are eaten by their larvae, these beetles are able to make their 

larval galleries in heartwood (a zone of low nutrition), in contrast to bark 

beetles, which feed in the more nutritious sapwood. Notes on the biology 

and distribution of four species of Xyleborus are given here. Many new 

invasive species within this group have been detected recently in North 

America. One invasive species, the redbay ambrosia beetle (Xyleborus 

glabratus Eichhoff), is discussed separately elsewhere in this publication. 

Species Comments on Biology and Gallery Shape

Xyleborus celsus Eichh. The largest member of the genus in the 

United States, this species’ galleries 

extend directly into the wood to a depth 

of 12 to 18 mm, then branch one or 

several times.

Xyleborus ferrugineus (F.) Galleries similar to X. celsus but smaller; 

galleries may also be longer, more 

winding, and branch less frequently. 

Xyleborus affinis Eichh. Galleries consist of elongate tunnels, 

off of which many transverse galleries 

branch. 

Xyleborus xylographus (Say) Attacks are commonly initiated at edges 

of wounds, deep crevices, or burrows 

made by other insects. Galleries run 

obliquely across the grain to depths of 

an inch or more.
258 Forest Pest Insects in North America:

Hosts Commonly Attacked Species Hosts

Xyleborus celsus Eichh. Breeds in dead, dying, and recently 

felled trees and stumps of hickory.

Xyleborus ferrugineus (F.) Breeds in dead, dying, or felled trees 

of a wide range of species including 

oak, hickory, ash, cypress, walnut, pine, 

beech, and sweetgum.

Xyleborus affinis Eichh. Breeds in dying trees and in green 

logs and lumber of various hardwood 

trees such as oak, hickory, sweetgum, 

river birch, hackberry, mimosa, 

persimmon, cypress, and black locust. 

Very destructive of sweet gum in 

southeastern United States along the 

Gulf of Mexico.

Xyleborus xylographus (Say) Attacks the lower portions of dying 

trees and the stumps, roots, and slash of 

its hosts. Found especially in oak, but 

also in hickory, chestnut, walnut, and 

pine.

Species Distribution

Xyleborus celsus Eichh. Found in eastern United States, west to 

Kansas.

Xyleborus ferrugineus (F.) Occurs from New York and Michigan, 

south to Florida and Texas.

Xyleborus affinis Eichh. Occurs in eastern United States east 

of a line from Michigan to Texas and 

south of New York.

Xyleborus xylographus (Say) Occurs in eastern Canada and in the 

United States, west to Kansas.

Distribution
A Photographic Guide 259

Images of Xyleborus

Ambrosia Beetles

Figure 1. Adults of Xyleborus celsus (top), Xyleborus ferrugineus (middle), and 

Xyleborus xylographus (bottom). (All photos: J.R. Baker and S.B. Bambara, 

North Carolina State University, Bugwood.org)
260 Forest Pest Insects in North America:

Natural enemies of these beetles are poorly known.

None 

Atkinson, T.H., R.J. Rabaglia, and D.E. Bright. 1990. Newly detected 

exotic species of Xyleborus (Scolytidae) in eastern North America, with a 

revised key to species. The Canadian Entomologist 122: 93-104.

Haack, R.A. 2006. Exotic bark- and wood-boring Coleoptera in the 

United States: recent establishments and interceptions. Canadian Journal 

of Forest Research 36(2): 269-288.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Xyleborus

Ambrosia Beetles

Articles

Images of Xyleborus

Ambrosia Beetles

(continued)

Figure 2. Galleries of Xyleborus celsus in cross sections of hickory (Carya) 

stems, showing intial deep pentration in the wood, with formation of branched 

galleries in the heart wood. (James Solomon, USDA Forest Service, 

Bugwood.org)
A Photographic Guide 261

77. Redbay Ambrosia Beetle, Xyleborus glabratus Eichhoff (Coleoptera: 

Curculionidae, Scolytinae) 

The redbay ambrosia beetle, Xyleborus glabratus Eichhoff, was detected 

in the United States for the first time in 2002 and has since caused 

extensive mortality of redbay (Persea borbonia [L.] Spreng.) and 

sassafras (Sassafras albidum [Nutt.] Nees) in coastal areas of South 

Carolina, Georgia, and parts of Florida. This ambrosia beetle is the vector 

of a lethal fungal pathogen (Raffaelea lauricola Harrington, Fraedrich 

and Aghayeva) that affects various species in the Lauraceae. Infected 

trees wilt and die within a few weeks or months of initial infection. This 

disease has been designated as “laurel wilt,” and it is believed to have 

arrived along with the redbay ambrosia beetle in wood packing material 

(crates and pallets) used in trade. Xyleborus glabratus is about 2 mm 

long, dark brown to almost black in color, nearly glabrous (shiny, without 

hairs), and has an abruptly slanting depression at the tip of it abdomen. 

However, positive confirmation of this species’ presence in a new area 

requires confirmation by a taxonomic specialist. Very little is known 

specifically about the biology of this beetle but it is likely similar to that 

of other members of this genus (see other insects in this publication). 

Adults and larvae inoculate new galleries with spores of a symbiotic 

pathogenic fungus, which are carried in special pockets at the base of 

the beetles’ mandibles. Males are flightless. Females can attack healthy 

hosts, and, in Florida and Georgia, female beetles fly throughout the year 

although at very low numbers in the winter. Signs of redbay ambrosia 

beetle attack include small strings of compacted sawdust protruding from 

the bark at the point of attack, but these strings soon disintegrate and 

are not unique to this species. Small holes the diameter of a paperclip 

wire in redbay are usually redbay ambrosia beetle entrance holes. 

Foliage of infested trees wilts because the fungal infection is systemic 

in the vascular elements of the tree, and foliage turns reddish brown. As 

infected trees start to die, they may also be attacked by other species of 

ambrosia beetle, particularly Xylosandrus crassiusculus (Motschulsky). 

In Florida, up to 90 percent of redbay trees died in less than two years 

following initial beetle invasion of a new site. Loss of redbay will 

likely severely harm populations of the Palamedes swallowtail (Papilio 

palamedes [Drury]), which feeds primarily on species of Persea. There 

is also considerable concern about the potential impact of laurel wilt on 

avocado (P. americana Miller), which is an economically important crop 

in Florida and California. 

In addition to redbay (P. borbonia) and sassafras (S. albidum), the wilt 

pathogen spread by the redbay ambrosia beetle has been recovered in 

the United States from avocado (P. americana), swampbay (P. palustris

[Raf.] Sarg.), pondspice (Litsea aestivalis [L.] Fernald), pondberry 

(Lindera melissifolia [Walter] Blume) and camphor (Cinnamomum 

camphora [L.] Sieb.). Pondspice and pondberry are of special concern 

because they are rare or endangered species. Avocado is of concern 

because of its economic importance.

Orientation to Pest

Hosts Commonly Attacked
262 Forest Pest Insects in North America:

The redbay beetle is native to South Asia (India, Myanmar) and East 

Asia (Japan, Taiwan). The invaded range in the United States includes 

coastal and adjacent areas of Georgia, South Carolina, and Florida, as 

well as parts of North Carolina, one area in Mississippi, and two counties 

in Alabama. 

Distribution

Figure 1. Map of the range of redbay ambrosia beetle, Xyleborus glabratus, in 

the United States. (USDA Forest Service - Southern Region • Forest Health 

Protection - Laurel Wilt)

Images of 

Redbay Ambrosia Beetle

Figure 2. Adult of 

the redbay ambrosia 

beetle; bottom, insect in 

natural position. (Top: 

Michael C. Thomas, 

Florida Department 

of Agriculture and 

Consumer Services, 

Bugwood.org; bottom: 

Shipher Wu)
A Photographic Guide 263

Images of Redbay 

Ambrosia Beetle

(continued)

Figure 3. Egg of redbay 

ambrosia beetle, inside 

gallery cut by female 

beetle. (Karolynne 

Griffiths, USDA APHIS 

PPQ, Bugwood.org)

Figure 4. Larva of 

redbay ambrosia beetle. 

(Bettaman/Shipher at 

shipher@gmail.com)

Figure 5. Ambrosia 

beetles produce 

frass tubes at points 

of entrance for adult 

beetles during the 

construction of their 

galleries. The long 

tubes are Xyleborus 

crassiusculus, while 

the very short tubes in 

the debarked area are 

redbay ambrosia beetle. 

(Ronald F. Billings, 

Texas Forest Service, 

Bugwood.org)
264 Forest Pest Insects in North America:

Images of Redbay 

Ambrosia Beetle

(continued)

Figure 6. Galleries of redbay beetle in redbay tree trunk, seen in cross section. 

(James Johnson, Georgia Forestry Commission, Bugwood.org)

Figure 7. Dark staining 

of the vascular tissue 

is a sign of the fungus 

associated with the 

redbay ambrosia 

beetle. (Both photos: 

Albert [Bud] Mayfield, 

USDA Forest Service, 

Bugwood.org)
A Photographic Guide 265

Images of Redbay 

Ambrosia Beetle

(continued)

Figure 8. Dead redbay killed by redbay ambrosia beetle and its associated 

fungus. The percentage of redbay mortality in this section of Florida forest 

increased from 10 percent to 81 percent within a year. (Albert [Bud] Mayfield, 

USDA Forest Service, Bugwood.org)

Natural enemies of redbay ambrosia beetle are unknown at this time.

http://www.freshfromflorida.com/pi/enpp/ento/x.glabratus.html; fact 

sheet of the Florida Department of Agriculture and Consumer Services, 

Division of Plant Industry.

http://spfnic.fs.fed.us/exfor/data/pestreports.cfm?pestidval=148&langd

isplay=english; fact sheet of Exotic Forest Pest Information System for 

North America.

http://www.invasivepests.org/products/gallery/xylgl1; fact sheet about 

risks to trees of moving firewood. 

http://www.redorbit.com/news/science/1685690/tiny_beetle_threatens_

floridas_avocado_industry/; redbay ambrosia beetle as a threat to 

avocado industry in the United States.

http://www.invasive.org/browse/subinfo.cfm?sub=10998; fact sheet of 

Bugwood Wiki.

http://www.public.iastate.edu/~tcharrin/LaurelWilt.html; factsheet on the 

wilt pathogen and links to PDF versions of relevant articles.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Redbay Ambrosia Beetle
266 Forest Pest Insects in North America:

Douce, G.K. and J. Johnson. 2005. Xyleborus glabratus in Georgia’s 

coastal forests. Georgia Forestry Commission Pest Alert, October 31, 

2005. 

Hanula, J.L., A.E. Mayfield, III, S.W. Fraedrich, and R.J. Rabaglia. 2008. 

Biology and host associations of redbay ambrosia beetle (Coleoptera: 

Curculionidae: Scolytinae), exotic vector of laurel wilt killing redbay 

trees in the southeastern United States. Journal of Economic Entomology

101: 1276-1286.

Fraedrich, S.W., T.C. Harrington, R.J. Rabaglia, M.D. Ulyshen, A.E. 

Mayfield, III, J.L. Hanula, J.M. Eickwort, and D.R. Miller. 2008. A 

fungal symbiont of the redbay ambrosia beetle causes a lethal wilt in 

redbay and other Lauraceae in the southeastern United States. Plant 

Disease 92: 215-224. (Available at http://www.public.iastate.edu/

~tcharrin/LaurelWilt.html).

Harrington, T.C., S.W. Fraedrich, and D.N. Aghayeva. 2008. Raffaelea 

lauricola, a new ambrosia beetle symbiont and pathogen on the 

Lauraceae. Mycotaxon 104: 399-404. (Available at http://www.public.

iastate.edu/~tcharrin/LaurelWilt.html). 

Mayfield, A.E, T.C. Harrington, S. Fraedrich, J. Hanula, and others. 

2009. Recovery plan for laurel wilt on redbay. In: Plant Diseases that 

Threaten U.S. Agriculture. Prepared for the National Plant Disease 

Recovery System, USDA and the American Phytopathological Society. 

27 p. (Available at http://www.public.iastate.edu/~tcharrin/LaurelWilt.

html). 

Articles on Redbay

Ambrosia Beetle
A Photographic Guide 267

78. Walnut Twig Beetle, Pityophthorus juglandis Blackman (Coleoptera: 

Curculionidae, Scolytinae) 

Orientation to Pest The walnut twig beetle, Pityophthorus juglandis Blackman, is the vector 

of a newly recognized fungal species, Geosmithia morbida Kolarík, 

Freeland, Utley, and Tisserat (Ascomycota: Hypocreales). This insectpathogen complex causes a fatal disease of eastern black walnut (Juglans 

nigra L.) and certain other species of walnut (Juglans). The common 

name for the disease is “thousand cankers” because death results from 

the coalescing of a great many small, separate cankers that originate at 

multiple points of twig beetle entry into twigs, branches, and main stems. 

Walnut twig beetle, a type of bark beetle native to the southwestern 

United States and parts of Mexico, is the only confirmed vector of the 

pathogen. In its early stages this disease appears as circular-to-oblong 

cankers that develop at the site of each walnut twig beetle gallery. 

Over time, cankers expand in the phloem, coalesce, and girdle twigs 

or branches. Geosmithia morbida does not move systemically within 

the tree and the pathogen is moved between trees only by the insect 

vector. Relatively large numbers of walnut twig beetles are needed to 

cause enough cankers to kill trees. The origin of this newly recognized 

pathogen is uncertain, but isolates from walnut species in the western 

United States show high genetic diversity, suggesting the fungus may be 

native to that region. Why the walnut twig beetle has recently increased 

to levels able to unleash a wave of walnut mortality is unknown, but is 

likely linked to its invasion of new parts of the country and attacks there 

on new species of walnut, some of which are highly susceptible. On 

black walnut in Colorado, the walnut twig beetle overwinters as adults in 

cavities excavated in the bark. Beetles colonize new hosts by attacking 

branches with rough bark, on the warmer side (exposed to sun). There 

are two overlapping generations per year in Colorado. Mass attacks are 

mediated by aggregation pheromones. Females dig oviposition galleries, 

inoculate with the galleries with their Geosmithia fungus, and then lay 

eggs along the gallery. Larvae emerge and dig tunnels, where they feed 

on fungus-infected wood. 

Trees that are highly susceptible to walnut twig beetle attack and fungal 

infection in the western United States include the California walnut (J. 

californica S. Wats.), Hinds walnut (J. hindsii [Jeps.] Jeps. ex R.E. Sm) 

(both native to California), and black walnut (J. nigra) (native only to 

the eastern United States). English walnut (J. regia L.) is moderately 

susceptible, while Arizona walnut (J. major [Torr.] A. Heller)—believed 

to be the original host for the beetle—appears to be quite tolerant. Two 

other important members of the walnut family—butternut (J. cinerea

L.) and pecan (Carya illinoinensis [Wangenh.] K. Koch)—appear to be 

resistant to the pathogen. 

Hosts Commonly Attacked
268 Forest Pest Insects in North America:

Walnut twig beetle and its associated pathogen are now reported from 

eight states in the western USA and three in the east (Tennessee, Virginia, 

and Pennsylvania). To what extent the western distribution reflects the 

native range versus recent spread into new locations is not certain. 

Figure 1. Distribution of the thousand cankers disease (plus, one eastern location 

in Knoxville, Tennessee). (USDA APHIS) 

Distribution

Images of 

Walnut Twig Beetle

Figure 2. Adult of the walnut twig beetle, Pityophthorus juglandis. (Steven Valley, 

Oregon Department of Agriculture, Bugwood.org)
A Photographic Guide 269

Images of Walnut 

Twig Beetle (continued)

Figure 3. Piles of boring dust at entrance of points of adult walnut twig beetle 

attack. (Whitney Cranshaw, Colorado State University, Bugwood.org) 

Figure 4. Adults of walnut twig beetles, in nuptial chamber. (Curtis Utley, CSUE, 

Bugwood.org)

Figure 5. Egg gallery of walnut twig beetle. (Whitney Cranshaw, Colorado State 

University, Bugwood.org)
270 Forest Pest Insects in North America:

Images of Walnut 

Twig Beetle (continued)

Figure 6. Larvae of walnut twig beetle. (Whitney Cranshaw, Colorado State 

University, Bugwood.org)

Figure 7. Galleries of walnut twig beetle in branch. (Whitney Cranshaw, Colorado 

State University, Bugwood.org)

Figure 8. Larva and pupa of walnut twig beetle, with a view of its fungal 

associate, Geosmithia morbida, which is sporulating profusely around the pupal 

cells. (Curtis Utley, CSUE, Bugwood.org) 
A Photographic Guide 271

Images of Walnut 

Twig Beetle (continued)

Figure 9. Weeping 

wounds are signs of 

attack by walnut twig 

beetle on English 

walnut, Juglans regia. 

Symptoms on black 

walnut are different. 

(Ned Tisserat, Colorado 

State University, 

Bugwood.org)

Figure 10. Emergence holes of walnut twig beetle. (Whitney Cranshaw, Colorado 

State University, Bugwood.org)
272 Forest Pest Insects in North America:

Images of Walnut 

Twig Beetle (continued)

Figure 11. Cankers that have developed around the galleries of walnut twig 

beetle. (Ned Tisserat, Colorado State University, Bugwood.org)

Figure 12. Branch death and dieback are early symptoms of walnut twig beetle 

attack (seen here on Arizona walnut). (Whitney Cranshaw, Colorado State 

University, Bugwood.org)

Figure 13. Black walnut 

trees dying or dead due 

to thousand cankers 

disease. (Curtis Utley, 

CSUE, Bugwood.org)
A Photographic Guide 273

Important Biological Control 

Agents Related to this 

Pest Species

Natural enemies of walnut twig beetle have not been reported.

http://tn.gov/agriculture/publications/regulatory/tc_pathwayanalysis.

pdf; a Tennessee website where a USDA APHIS document is posted that 

gives background information on vector and thousand cankers pathogen, 

plus an analysis of likely means of further spread.

http://caforestpestcouncil.org/wp-content/uploads/2009/05/stevenseybold-walnut.pdf; a Power Point presentation from a meeting that 

covers various aspects of impact of walnut twig beetle in California.

http://caps.ceris.purdue.edu/webfm_send/854; provides a pictorial 

key for identification of walnut twig beetle from its many con-generic 

species.

http://www.invasivepests.org/products/gallery/pitju1.html.

http://www.michiganloggingcompany.com/Black-Walnut-Black-Death; 

contains a video on aspects of the problem.

http://www.ext.colostate.edu/pubs/insect/0812_alert.pdf; fact sheet of the 

Colorado State University.

http://www.fs.fed.us/foresthealth/fhm/sp/tcd/tcd.shtml; USDA Forest 

Service page on thousand cankers disease and walnut twig beetle.

Tisserat, N., W. Cranshaw, D. Leatherman, C. Utley, and K. Alexander. 

2009. Black walnut mortality caused by the walnut twig beetle and 

thousand cankers disease. Plant Health Progress. August 11, 2009. 10 p. 

Grant, J.F., M.T. Windham, W.G. Haun, G.J. Wiggins, and P.L. Lambdin. 

2011. Initial assessment of thousand cankers disease on black walnut, 

Juglans nigra, in eastern Tennessee. Forests 2: 741-748.

Web Links for Information 

on Walnut Twig Beetle

Articles
274 Forest Pest Insects in North America:

79. Striped Ambrosia Beetle, Trypodendron lineatum (Olivier) (Coleoptera: 

Curculionidae, Scolytinae) 

The striped ambrosia beetle, Trypodendron lineatum (Olivier), has long 

been considered the most damaging ambrosia beetle in the western 

United States (but see also the walnut twig borer, Pityophthorus 

juglandis Blackman). It is particularly important in coastal areas of 

British Columbia in Canada. Attacks are principally on dead and dying 

timbers created by wind storms, fire, bark beetle attack, or long in-field 

storage of cut logs. Females bore into the xylem and then larvae make 

lateral galleries where they feed, pupate, and later emerge. There is 

generally one generation per year. 

Striped ambrosia beetles attack conifers in Abies, Picea, Pseudotsuga, 

Tsuga, Larix, and Pinus. They rarely attack hardwoods. 

The striped ambrosia beetle is Holarctic in distribution. In the western 

United States, it is found from New Mexico and southern California to 

the northern edge of the boreal forest in Canada. In the eastern United 

States, it is found in New England and along the Appalachians to the 

mountains of western North Carolina. 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of 

Striped Ambrosia Beetle

Figure 1. Adult of the striped ambrosia beetle, Trypodendron lineatum. 

(Maja Jurc, University of Ljubljana, Bugwood.org)
A Photographic Guide 275

Images of Striped

Ambrosia Beetle

(continued)

Figure 2. Galleries of striped ambrosia beetle. Top left: galleries made by females 

to access interior of log; bottom left: the up and down galleries off the adult’s 

gallery made by larvae; right: diagram of the spatial relation of the two types of 

galleries inside a log. (Top left: Wayne Brewer, Auburn University, Bugwood.org; 

bottom left: Petr Kapitola, State Phytosanitary Administration, Bugwood.org; 

right: Robert Dzwonkowski, Bugwood.org)

Figure 3. Emergence 

holes (see sawdust) of 

striped ambrosia beetles 

in felled Norway spruce 

(Picea abies [L.] Karst.). 

(Both photos: 

Beat Forster, Swiss 

Federal Institute for 

Forest, Snow and 

Landscape Research, 

Bugwood.org)
276 Forest Pest Insects in North America:

Images of Striped

Ambrosia Beetle

(continued)

Figure 4. Emergence 

holes of striped 

ambrosia beetles. (Milan 

Zubrik, Forest Research 

Institute - Slovakia, 

Bugwood.org)

Figure 5. Thanasimus formicarius, a clerid predator that likely feeds on 

striped ambrosia beetle. (Scott Bauer, USDA Agricultural Research Service, 

Bugwood.org)
A Photographic Guide 277

Little is known of the natural enemies of this ambrosia beetle. The clerid 

Thanasimus formicarius (L.) responds to the pheromone of T. lineatum, 

which suggests that it may use the striped ambrosia beetle as food. 

http://www.forestry.ubc.ca/fetch21/FRST308/lab7/trypodendron_

lineatum/striped.html; fact sheet of the University of British Columbia, 

which includes a short video of damage from this beetle to stored logs. 

http://www.barkbeetles.org/biocontol/stripedambrosiabeetle.html; fact 

sheet from Bugwood Wiki on this beetle.

Lindgren, B.S., S.E.R. Hoover, A.M. MacIsaac, C.I. Keeling, and K.N. 

Slessor. 2000. Lineatin enantiomer preference, flight periods, and effect 

of pheromone concentration and trap length on three sympatric species 

of Trypodendron (Coleoptera: Scolytidae). The Canadian Entomologist

132: 877-887.

Park, J. and M.L. Reid. 2007. Distribution of a bark beetle, Trypodendron 

lineatum, in a harvested landscape. Forest Ecology and Management

242(2/3): 236-242.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Striped Ambrosia Beetle

Articles
278 Forest Pest Insects in North America:

80. Black Twig Borer, Xylosandrus compactus (Eichhoff) (Coleoptera: 

Curculionidae, Scolytinae) 

Orientation to Pest The black twig borer, Xylosandrus compactus (Eichhoff), is an invasive 

ambrosia beetle from Asia present in Hawaii and coastal regions of the 

southeastern United States. Females bore into healthy twigs of over 200 

hardwood species, where they lay loose clusters of eggs and inoculate 

their galleries with a symbiotic fungus (Fusarium solani [Mart.] Sacc.) 

on which their larvae later feed. Twigs may be colonized by one or 

several females, depending on twig size. Mature larvae pupae in the 

gallery and males, which are flightless, mate with females in the twig 

before new females emerge. Males never leave the twig. Attacked trees 

or other plants are usually not killed but may suffer considerable damage. 

In Hawaii, this species is an important pest of coffee (Coffea canephora

Pierre [esp. var. robusta Ineac]).

Table 1. Characteristics of 4 Xylosandrus species present in the 

southeastern United States (from University of Florida fact sheet on 

black twig borer seen at http://entnemdept.ufl.edu/creatures/trees/black_

twig_borer.htm)

Characteristic X. compactus X. crassiusculus X. germanus X. zimmermanni

Female size 1.4-1.9 mm 2.1-2.9 mm 2.0-2.4 mm 1.3-1.5 mm

Surface of 

declivity

Shining and 

smooth

Dull and 

granulate

Shining Shining

Hair tuft 

on base of 

pronotum

Forms 

transverse row

 — — Tuft oriented 

longitudinally

Geographic 

location

Throughout 

Florida and 

from North 

Carolina to 

eastern Texas

Throughout 

Florida and from 

North Carolina 

to eastern Texas

From 

Connecticut to 

Missouri, east 

Texas, and 

central Georgia. 

Might appear in 

North Florida

Subtropical 

South Florida 

and Mexico to 

Venezuela.

Common host 

material

In small twigs 

on healthy, cut 

and stressed 

plants

In wood of large 

twigs, small 

branches and 

stems

In wood of large 

twigs, small 

branches and 

stems

Only in 

unhealthy, 

cut, or broken 

branches 1-3 

cm diameter
A Photographic Guide 279

Hosts are quite varied but include maple (Acer spp.), hickory (Carya

spp.), magnolia (Magnolia spp.), dogwood (Cornus spp.), oaks (Quercus

spp.), and willows (Salix spp.), among others.

Black twig borer has been reported from Hawaii and in North America 

from coastal parts of North Carolina to Texas (USA). Globally this 

species has a wide distribution in tropical and subtropical areas.

Hosts Commonly Attacked

Distribution

Images of 

Black Twig Borer

Figure 1. Adult of black twig beetle, Xylosandrus compactus; right, adult on 

coffee. (Left: J.R. Baker and S.B. Bambara, North Carolina State University, 

Bugwood.org; right: Scot Nelson, University of Hawaii at Manoa, Bugwood.org)

Figure 2. Entrance and exit holes of adult black twig beetles in a branch of a koa 

tree (Acacia koa Gray) in Hawaii. (Scot Nelson, University of Hawaii at Manoa, 

Bugwood.org)
280 Forest Pest Insects in North America:

Images of Black

Twig Borer (continued)

Figure 3. Galleries of 

black twig beetle larvae 

in magnolia. (Forrest L. 

Oliveria, USDA Forest 

Service, Bugwood.org)

Figure 4. Cross-sectional views of galleries of Xylosandrus germanus (Blandford) 

in pecan. (Jerry A. Payne, USDA Agricultural Research Service, Bugwood.org)
A Photographic Guide 281

Figure 6. Death of small cypress branch (left) caused by black twig borer; injury 

to Acacia koa branch (right). (Left: Andrew J. Boone, South Carolina Forestry 

Commission, Bugwood.org; right: Scot Nelson, University of Hawaii at Manoa, 

Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

Little is known of the natural enemies of black twig borer.

Figure 5. “Toothpick” 

frass ejected from bore 

hole of Xylosandrus 

crassiusculus (Eichhoff). 

(G. Keith Douce, 

University of Georgia, 

Bugwood.org)

Images of Black

Twig Borer (continued)
282 Forest Pest Insects in North America:

Web Links for Information 

on Black Twig Beetle

http://www.extento.hawaii.edu/kbase/crop/type/xylosand.htm; fact sheet 

of the University of Hawaii Extension Service.

http://entnemdept.ufl.edu/creatures/trees/black_twig_borer.htm; fact 

sheet of University of Florida.

Ngoan, N.D., R.C. Wilkinson, D.E. Short, C.S. Moses, and J.R. 

Mangold. 1976. Biology of an introduced ambrosia beetle, Xylosandrus 

compactus, in Florida. Annals of the Entomological Society of America

69: 872-876.

Masuya, H. 2007. Note on the dieback of Cornus florida caused by 

Xylosandrus compactus. Bulletin of the Forestry and Forest Products 

Research Institute, Ibaraki 402: 59-63.

Articles
A Photographic Guide 283

81. Larger Pine Shoot Beetle, Tomicus piniperda (L.) (Coleoptera: 

Curculionidae, Scolytinae) 

Orientation to Pest The larger pine shoot beetle, Tomicus piniperda (L.), is an invasive 

species in North America that is found throughout much of Europe, as 

well as parts of North Africa (Algeria, Canary Islands) and Asia (China, 

Japan, Korea, and Turkey). Both larvae and adults are damaging to a 

wide variety of pines. Larvae develop under bark of branches and trunks 

of suppressed or recently fallen trees, as well as in recently cut stumps. 

Adults cause more important damage by tunneling in live shoots and 

leaders of healthy pine trees, reducing growth and deforming tree shape, 

which can cause important losses in Christmas tree production. Larger 

pine shoot beetles overwinter as adults in short galleries in the outer 

bark of host trees near the ground. Adults emerge in late winter or early 

spring and construct brood galleries in suitable host material. At times, 

these parent adults (P1

) will emerge, shoot feed, and then construct 

another brood gallery. The brood adults (F1

) emerge in summer and fly 

to the shoots of pine trees where they feed until fall. A single brood adult 

(F1

 generation) will feed in multiple shoots during the summer months. 

Brood adults do not become sexually mature until they overwinter. 

The larger pine shoot beetle is also believed to vector or be associated 

with several fungi that are pathogens in conifers, including Ophiostoma 

minus (Hedgc.) Syd. et P. Syd., and various blue-staining fungi such as 

species of Leptographium. Outbreaks of this pest are triggered when 

there is a sudden increase in the amount of breeding material available 

in early spring, such as following severe winter storms, winter logging 

operations, or Christmas tree plantations with recently cut stumps or 

piles of unsold trees. Silvicultural practices during fall and winter such as 

reducing the amounts of pine logging slash left in the forest and cutting 

stumps low to the ground will limit number of breeding sites available 

for this bark beetle. 

The preferred host in Europe and so far in North America is Scots pine 

(Pinus sylvestris L.), but other native pines such as red pine (Pinus 

resinosa Sol. ex Aiton) are commonly infested. However, all native 

North American pines are potential hosts. 

Hosts Commonly Attacked
284 Forest Pest Insects in North America:

Native to Eurasia, this species is invasive in parts of the United States, 

from Wisconsin to Maine and south to West Virginia.

Figure 1. Distribution of the larger pine shoot beetle as of 2005. (National 

Agricultural Pest Information System)

Distribution

Figure 2. Adult of larger shoot beetle, Tomicus piniperda. (Pest and Diseases 

Image Library, Bugwood.org)

Images of Larger

Pine Shoot Beetle
A Photographic Guide 285

Images of Larger Pine

Shoot Beetle (continued)

Figure 3. Diagnostic 

characters for 

recognition of larger 

pine shoot beetle: (a) 

absence of setae in the 

second row (counting 

from the midline), 

toward the rear of 

the beetle (top) and 

(b) a six-segmented 

funicle preceeding the 

anntennal club (bottom). 

(Top: Pest and 

Diseases Image Library, 

Bugwood.org; bottom: 

Eric Allen - Canadian 

Forest Service, Pacific 

Forestry Centre, 

Victoria, British 

Columbia) 

Figure 4. Seasonal life history of the larger shoot beetle in the Great Lakes region 

of the United States. (E. Richard Hoebeke, Cornell University, Bugwood.org)
286 Forest Pest Insects in North America:

Figure 5. Adults of larger shoot beetle, showing how adults bore into shoots 

causing then to die and fall off. Top, adult boring into shoot; bottom left, adult 

inside feeding tunnel in shoot; bottom right, opening in shoot made by adult 

beetle to enter feeding site. (Top: Steve Passoa, USDA APHIS PPQ, 

Bugwood.org; bottom left and right: Gyorgy Csoka, Hungary Forest Research 

Institute, Bugwood.org)

Images of Larger Pine

Shoot Beetle (continued)

Figure 6. Pitch tubes of larger shoot beetle on trunk. (Petr Kapitola, State 

Phytosanitary Administration, Bugwood.org)
A Photographic Guide 287

Images of Larger Pine

Shoot Beetle (continued)

Figure 7. Galleries of the larger pine shoot beetle; left, see the deeply etched 

vertical oviposition galleries and right, larval galleries radiating out horizontally 

from the vertical oviposition gallery. (Left: Hannes Lemme, Bugwood.org; right: 

Milan Zubrik, Forest Research Institute - Slovakia, Bugwood.org)

Figure 8. Blue stain damage in logs affected by the larger shoot beetle. (USDA 

Forest Service - Northeastern Area Archive, USDA Forest Service, Bugwood.org)
288 Forest Pest Insects in North America:

Images of Larger Pine

Shoot Beetle (continued)

Figure 9. Exit holes of the larger shoot beetle. (Milan Zubrik, Forest Research 

Institute - Slovakia, Bugwood.org)

Figure 10. Tops of pines (left) showing loss of branches from feeding of adults of 

larger shoot beetle; fallen branches (right) caused by adult feeding. (Left: 

E. Richard Hoebeke, Cornell University, Bugwood.org; right: Hannes Lemme, 

Bugwood.org)

Figure 11. An important predator in Europe of the engraver beetle, the redbellied clerid beetle, Thanasimus formicarius (L.) (left, adult; right, larva). (Left: 

Scott Bauer, USDA Agricultural Research Service, Bugwood.org; right: Jiri Hulcr, 

Michigan State University, Bugwood.org)
A Photographic Guide 289

A variety of natural enemies have been recorded attacking the larger 

pine shoot beetle in Europe, especially the clerid predator Thanasimus 

formicarius (L.) and the pteromalid parasitoid Rhopalicus suspensus

Ratz., both of which at some times and places have been observed to kill 

70-80 percent of the larger shoot beetles’ larvae or pupae.

http://www.na.fs.fed.us/spfo/pubs/pest_al/shootbeetle/shootbeetle.htm; 

USDA Forest Service pest leaflet.

http://warehouse.pfc.forestry.ca/pfc/5134.pdf; fact sheet of the Canadian 

Forest Service, British Columbia.

http://entnemdept.ufl.edu/creatures/trees/beetles/pine_shoot_beetle.htm; 

fact sheet of the University of Florida.

http://en.wikipedia.org/wiki/Tomicus_piniperda; page from Wikipedia.

http://www.na.fs.fed.us/spfo/pubs/pest_al/shootbeetle/shootbeetle.htm; 

pest alert of the USDA Forest Service, Northeastern Area.

http://www.issg.org/database/species/ecology.asp?si=1200; fact sheet 

of the Global Invasive Species Database, with a discussion of routes of 

introduction of this species to new areas. 

Morgan, R.E., P. de Groot, and S.M. Smith. 2004. Susceptibility of 

pine plantations to attack by the pine shoot beetle (Tomicus piniperda) 

in southern Ontario. Canadian Journal of Forest Research 34(12): 

2528-2540.

Kennedy, A.A. and D.G. McCullough. 2002. Phenology of the larger 

European pine shoot beetle Tomicus piniperda (L.) (Coleoptera: 

Scolytidae) in relation to native bark beetles and natural enemies in pine 

stands. Environmental Entomology 31: 261-272.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information

on Larger Pine Shoot Beetle

Articles
290 Forest Pest Insects in North America:

82. White Pine Cone Beetle, Conophthorus coniperda (Schwarz) 

(Coleoptera: Curculionidae, Scolytinae) 

The white pine cone beetle, Conophthorus coniperda (Schwarz), infests 

cones of eastern white pine (Pinus strobus L.) and is an important pest 

of seed production in natural stands and in seed orchards. Cones are 

initially attacked by adult female beetles that start tunneling in the cone 

stalk or base. This severs the conductive tissue that connects the twig 

and cone, killing the cone. A small pitch tube generally marks the entry 

point. Individual female beetles extend an egg gallery down the central 

axis of a cone. Eggs are laid along this gallery. Larvae feed on seeds 

and associated tissues until they reach maturity. Larvae then pupate, and 

later emerge as adults, which darken over a few days. Development from 

egg to adult occurs in one growing season, and there is one generation 

per year. Female beetles can attack and oviposit in more than one cone. 

Infested cones stop growing in length after they are attacked. So, cones 

attacked in the early spring will be very small when they die, while 

cones attacked late in the summer are much larger in size. Infested 

cones shrivel, turn brown, and become hard. Because stalks of infested 

cones are severed, they can easily be removed by hand from a branch. 

Uninfested cones or cones attacked by other seed and cone insects, in 

contrast, adhere tightly to branches and may require a hand-clipper to 

remove. Infested cones eventually fall from trees, and beetles spend 

the winter within infested cones on the forest floor. In early spring, 

beetles chew emergence holes and fly from cones on the ground into tree 

crowns where they locate new host material. This is the most important 

pest of white pine seed orchards, sometimes destroying most or all of 

a developing seed crop. Damage is concentrated on second year cones, 

but first year conelets are also attacked. Beetles, when they are on the 

ground, can be killed using a low-intensity ground fire, a practice that is 

employed for control in seed orchards.

Eastern white pine (P. strobus) is the only host of this species, but there 

are other species of Conophthorus associated with other pines.

The white pine cone beetle is found throughout the range of eastern 

white pine, from eastern Canada (Quebec, Ontario, Nova Scotia), south 

to North Carolina, and west to Minnesota.

Orientation to Pest

Hosts Commonly Attacked

Distribution
A Photographic Guide 291

Images of White

Pine Cone Beetle

Figure 1. Adult white pine cone beetle, Conophthorus coniperda. (J.R. Baker and 

S.B. Bambara, North Carolina State University, Bugwood.org)

Figure 2. A female beetle can be seen initiating an attack at the base of a white 

pine cone where the cone stalk enters the cone. (Larry R. Barber, USDA Forest 

Service, Bugwood.org)
292 Forest Pest Insects in North America:

Images of White Pine

Cone Beetle (continued)

Figure 3. Egg-laying 

gallery of a cone beetle 

(Conophthorus sp.) in 

the center of a cone 

that has been cut in 

half. (Steven Katovich, 

USDA Forest Service, 

Bugwood.org)

Figure 4. Damage 

inside a white pine cone 

caused by feeding of 

larvae of white pine 

cone beetle. (Robert L. 

Anderson, USDA Forest 

Service, Bugwood.org)

Figure 5. Dead white 

pine cones, infested 

by larvae of white pine 

cone beetle may hang 

on trees for a period of 

time before dropping 

to ground. (Steven 

Katovich, USDA Forest 

Service, Bugwood.org)
A Photographic Guide 293

Images of White Pine

Cone Beetle (continued)

Figure 6. The length of dead infested cones can vary greatly. Small dead cones 

are those attacked in early spring and larger dead cones are those attacked in 

late summer. (Steven Katovich, USDA Forest Service, Bugwood.org)

Figure 7. Low intensity burns can be used in spring to control adults of white pine 

cone beetle before they emerge from cones on the ground. (Larry R. Barber, 

USDA Forest Service, Bugwood.org)

Natural enemies of this insect have not been reported.

None

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on White Pine Cone Beetle
294 Forest Pest Insects in North America:

Articles on White

Pine Cone Beetle

Wade, D.D., G.L. Debarr, L.R. Barber, and E. Manchester. 1989. 

Prescribed fire - a cost effective control for white pine cone beetle. In: 

MacIver, D.C., H. Auld, and R. Whitewood (eds). Proceedings of the 

10th Conference on Fire and Forest Meteorology. Forestry Canada, 

Petawawa National Forestry Institute (PNFI), Chalk River, Ontario: 

117-121. 

De Groot, P. 1990. The taxonomy, life history and control of 

Conophthorus (Coleoptera: Scolytidae) in eastern North America. 

Proceedings - Cone and seed pest workshop, 4 October 1989.

Information Report N-X-274, Forestry Canada, Newfoundland and 

Labrador Region, St. John’s, Newfoundland, Canada: 37-46.

Trudel, R., C. Guertin, and P. De Groot. 2004. Use of pityol to reduce 

damage by the white pine cone beetle, Conophthorus coniperda

(Col., Scolytidae) in seed orchards. Journal of Applied Entomology 

128: 403-406.
A Photographic Guide 295

83. Lodgepole Cone Beetle, Conophthorus ponderosae Hopkins 

(Coleoptera: Curculionidae, Scolytinae) 

Orientation to Pest Western cone beetles (Conophthorus spp.) were historically described 

based on their principal host trees. The sugar pine cone beetle 

(Conophthorus lambertianae Hopkins) was described from Pinus 

lambertiana Douglas, but it was later declared a junior synonym of 

Conophthorus ponderosae Hopkins, which was formerly known as the 

ponderosa cone beetle, but is now referred to as the lodgepole cone 

beetle (Wood 1977). Later work based on similarities among beetle 

cuticular hydrocarbons (Page et al. 1990), however, suggested that the 

sugar pine-feeding population of C. ponderosae may indeed be a separate 

species (the former C. lambertianae), but it was not formerly reinstated 

taxonomically. The possible validity of a sugar pine-feeding species is 

consistent with recent DNA studies that shown that there likely have 

been more speciation events in this genus than were formerly suspected. 

But these appear to have been driven by geographic isolation, not affinity 

to particular host species (Cognato et al., 2005), although sometimes 

the two go together. The ponderosa cone beetle (C. ponderosae in the 

wide sense), as discussed here, is composed of several populations as 

noted above, whose relatedness is not certain. The population associated 

with ponderosa (Pinus ponderosa Douglas ex C. Lawson), lodgepole 

(P. contorta var. latifolia Douglas), and Jeffrey (P. jeffreyi Balf.) pines is 

found from Washington to California, and in Arizona and New Mexico. 

The population associated with sugar pine (P. lambertiana Douglas) is 

found in California, Nevada and Oregon, where it feeds mostly on 

P. lambertiana and sometimes on western white pine (P. monticola

Douglas ex D. Don).

For purposes of this presentation, we discuss C. ponderosae in the wide 

sense, inclusive of C. lambertianae. Regardless of their specie-level 

status, the biologies of these populations are very similar. In broad 

terms, their biology is similar to that of the white pine cone beetle 

(Conophthorus coniperda [Schwarz]) in the eastern United States. Adults 

bore into the pedicles of immature, second year pine cones in the spring 

and dig a tunnel along the length of the cone, where the female deposits 

her eggs. Larvae feed on the scales, seeds, and tissues of the cone. 

Pupation occurs within the cone and adults overwinter on the soil in 

fallen cones. For the sugar-pine feeding population (“C. lambertianae”), 

adults emerge from cones in the fall and move to twigs, boring into them 

to feed, where they remain over winter. 
296 Forest Pest Insects in North America:

The C. ponderosae population associated with sugar pine is the most 

destructive of the western Conophthorus cone beetles. It sometimes 

destroys up to 75 percent of sugar pine seeds in some years, making it an 

important pest in sugar pine seed orchards. Similarly, the C. ponderosae

population associated with western white pine in British Columbia, 

Washington, and Idaho has caused important losses in seed collection 

stands and seeds orchards of that species. The other populations of 

C. ponderosae have similar effects on other species of pines in seed 

orchards, but the typical rate of seed destruction is lower.

The lodgepole cone beetle, in the wide sense, attacks ponderosa 

(P. ponderosa), lodgepole (P. contorta var. latifolia), Jeffrey (P. jeffreyi), 

sugar (P. lambertiana), and western white (P. monticola) pines. 

The lodgepole cone beetle, in the wide sense, is found from British 

Columbia to California, as well as in Idaho, Nevada, Arizona, and 

New Mexico.

Orientation to Pest

(continued)

Hosts Commonly Attacked

Distribution

Images of 

Lodgepole Cone Beetle

Figure 1. Adult of lodgepole cone beetle (Conophthorus ponderosae). 

(D. Manastyrski, Bugwood.org) 

Figure 2. Adult cone 

beetles (Conophthorus

sp.) tunnel in pine cones 

and their larvae feed on 

the immature seeds and 

other tissues. (Steven 

Katovich, USDA Forest 

Service, Bugwood.org)
A Photographic Guide 297

Images of Lodgepole

Cone Beetle (continued)

Figure 3. Pitch tube of Conophthorus ponderosae at base of cones in western 

white pine (P. monticola) at site of adult entrance. (Ward Strong, BC Ministry of 

Forests, Bugwood.org)

Figure 4. Internal 

appearance of pine 

cones infested by 

larvae of lodgepole 

cone beetles. (USDA 

Forest Service Archive, 

USDA Forest Service, 

Bugwood.org)
298 Forest Pest Insects in North America:

Images of Lodgepole

Cone Beetle (continued)

Figure 5. Late instar Conophthorus ponderosae larva exposed in a dissected 

western white pine (P. monticola) cone. (Canadian Forest Service Archive, 

Canadian Forest Service, Bugwood.org)

Figure 6. Reduced 

size of cones of 

ponderosa pine (top) 

and western white pine 

(bottom) infested by 

the lodgepole cone 

beetle compared to 

the larger, normal 

cones. (Top: Sandy 

Kegley, USDA Forest 

Service, Bugwood.org; 

bottom: Ward Strong, 

BC Ministry of Forests, 

Bugwood.org)
A Photographic Guide 299

Little is known of the natural enemies of populations of lodgepole 

cone beetle. But larvae of the population found on sugar pine 

(“C. lambertianae”) are attacked in the cone by the bethylid wasp 

Cephalonomia utahensis Brues. Adult beetles are attacked by both the 

predatory clerid Enoclerus lecontei Wolcott and are parasitized by the 

pteromalid wasp Tomicobia tibialis Ashmead.

http://www.barkbeetles.org/biocontol/sugarpineconebeetle.html; fact 

sheet from University of California with an emphasis on potential for 

biological control of this pest.

http://www.fgcouncil.bc.ca/PM-Factsheet11-Conophthorus-ponderosae.

pdf; fact sheet from the provincial forest council of British Columbia, 

Canada.

Wood, S.L. 1977. New synonymy and new species of American bark 

beetles (Coleoptera: Scolytidae), part V. Great Basin Naturalist 37: 

383-394.

Page, M., L.J. Nelson, M.I. Haverty, and G.J. Blomquist. 1990. 

Cuticular hydrocarbons of eight species of North American cone beetles, 

Conophthorus Hopkins. Journal of Chemical Ecology 16: 1173-1198.

Furniss, M.M. 1997. Conophthorus ponderosae (Coleoptera: Scolytidae) 

infesting lodgepole pine cones in Idaho. Environmental Entomology 26: 

855-858.

Bennett, R. 2000. Management of cone beetles (Conophthorus 

ponderosae, Scolytidae) in blister rust resistant western white pine seed 

orchards in British Columbia. Seed and Seedlings Extension Topics 

12: 16-18. (Available at http://www.for.gov.bc.ca/hti/publications/

newsletters/Vol1201Aug20.pdf).

Cognato, A.I., N.E. Gillette, R. Campos Bolaños, and F.A.H. Sperling. 

2005. Mitochondrial phylogeny of pine cone beetles (Scolytinae, 

Conophthorus) and their affiliation with geographic area and host. 

Molecular Phylogenetics and Evolution 36: 494-508. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Lodgepole Cone Beetle

Articles
300 Forest Pest Insects in North America:

85. May and June Beetles, Phyllophaga spp. (Coleoptera: Scarabaeidae) 

Orientation to Pest May and June beetles (Phyllophaga spp.) are a group of scarab beetles 

whose larvae feed on the roots of trees and other plants, which can 

significantly affect survival of seedlings or young trees in plantations. 

This is a very large group of beetles native to North America. There 

are more than 250 Phyllophaga species in North America. Most U.S. 

species occur in the eastern half of the country. In the western part of the 

country, this group is most numerous in Arizona. Many species occur 

in Mexico. Here, we present a general view of the biology of the group 

and mention a few species that are sometimes forestry pests. Adults of 

several important species emerge in spring and early summer (May and 

June, especially, hence their name). Adults are large, often brown, beetles 

that are active in evening or early night and are big enough to be easily 

noticed (1-3 cm long). Eggs are laid in groups in the soil, about 8-18 cm 

deep, with each egg enclosed in a ball of dirt. Newly hatched larvae feed 

on organic matter in the soil but soon switch to feeding on rootlets of tree 

seedlings, grasses, or other plants. Winter is spent in the soil and larvae 

move up and down to stay below the frost line. Mature larvae pupate in 

the soil. One to three years are required to reach maturity in the southern 

states, 2-3 years in mid-latitudes of the United States, and 3-4 years in 

northern states and Canada. Because of the multi-year life cycle and large 

number of species, relatively little is known of the population dynamics 

of particular species. 

Damage from Phyllophaga species can occur from either adults or 

larvae. Adults feed at night on the foliage of many plants including 

broad-leaved trees, shrubs, and some conifers. Damage from adults is 

spotty, but when populations are high trees can be heavily defoliated in 

woodlots or forest edges. Larvae, called white grubs (a name applied 

to the whole scarab family), feed in the soil on roots of both grasses 

and woody plants. Damage from Phyllophaga grubs occurs in forest 

nurseries and plantations the southern and eastern United States. In the 

western United States, damage from Phyllophaga grubs is less common 

but is occasionally significant to coniferous seedlings in plantations 

and nurseries on newly broken sandy land. In the eastern United States, 

damage to forest nurseries and young plantations can be severe at times. 

In Michigan and Wisconsin in red pine plantations on sandy soils, as few 

as 0.75 grubs per cubic foot of soil were found to kill 15-45 percent of 

red pine seedlings. 
A Photographic Guide 301

Hosts Commonly Attacked 

and Distribution of Some 

Phyllophaga Species

Common Species Comments on Biology (from Drooz 1985)

Phyllophaga crenulata

(Froclich)

P. crenulata occurs throughout the eastern United 

States. Adults feed on a wide variety of hardwoods, 

especially persimmon, hickory, basswood, willow, 

birch, and buckeye. The larvae are often serious pests 

in coniferous nurseries in the Lake States.

Phyllophaga drakei

(Kirby)

P. drakei occurs throughout most of the eastern United 

States and southern Canada. Adults feed on the 

leaves of beech, birch, dogwood, maple, basswood, 

elm, and willow. The larvae are important pests in 

forest nurseries and plantations in the Lake States and 

Canada.

Phyllophaga forsteri

(Burmeister)

P. forsteri occurs throughout the eastern United 

States. Adults feed on a wide variety of hardwoods 

such as beech, birch, elm, magnolia, maple, tupelo, 

walnut, and willow. There are also reports of their 

feeding on pine. The larvae are often destructive in 

nurseries in the southern United States.

Phyllophaga implicita

(Horn)

P. implicita occurs mostly in the Mississippi and Ohio 

River Valleys. Adults feed on beech, dogwood, elm, 

sycamore, tupelo, walnut, willow, basswood, maple, 

and other plants. The larvae killed millions of seedlings 

in nurseries in Iowa in the 1930s.

Phyllophaga luctuosa

(Horn)

P. luctuosa occurs primarily along the Atlantic and Gulf 

coasts in sandy, oak-pine regions, but also farther 

north and inland to Tennessee, Oklahoma, and Iowa. 

Adults feed on persimmon, mulberry, tupelo, walnut, 

willow, beech, birch, and loblolly and longleaf pines. 

The larvae are often destructive in nurseries and, 

probably, plantations.

Phyllophaga 

prununculina

(Burmeister)

P. prununculina occurs in the South Atlantic and Gulf 

Coast States. It is especially common in the Sand Hills 

of South Carolina. Adults feed on pines, especially 

loblolly and longleaf, and sometimes oaks and 

persimmon. The larvae have caused serious losses in 

pine nurseries and plantations in South Carolina.

Phyllophaga prunina

(LeConte) 

P. prunina occurs throughout the central United 

States east of the Rocky Mountains. Adults feed on 

hardwoods, including beech, elm, walnut, basswood, 

and willow. Feeding on pine has also been observed. 

Larvae are injurious in nurseries in the Lake states.

Phyllophaga rugosa

(Melsheimer)

P. rugosa occurs mostly in the northern United States 

and southern Canada. Adults feed on a wide variety 

of hardwoods. The larvae are often destructive in 

coniferous nurseries in the Lake States.

Phyllophaga tristis (F.) P. tristis occurs throughout the eastern United States 

and in southern Canada. Adults prefer the foliage of 

oaks but also feed on maple, persimmon, hickory, 

elm, and willow. Larvae have caused serious losses in 

nurseries in the Lake States.
302 Forest Pest Insects in North America:

Images of May

and June Beetles

Figure 1. Adults of two 

species of Phyllophaga

beetles, showing 

general body form 

shared by most species 

in genus. (Top: 

Steven Katovich, 

USDA Forest Service, 

Bugwood.org; bottom: 

Whitney Cranshaw, 

Colorado State 

University, 

Bugwood.org)

Figure 2. Species identification of larval scarabs (white grubs) is largely based 

on the setal patterns on the tip of the abdomen (the raster) (here a white grub in 

another genus, the oriental beetle Anomala orientalis [Waterhouse]). (H. Sawada, 

Bugwood.org) 
A Photographic Guide 303

Images of May and

June Beetles (continued)

Figure 3. Diagram of life 

cycle of Phyllophaga 

implicita. (North Dakota 

State University 

Extension Service)

Figure 4. The C-shape 

form of a “white grub” 

and visible legs are 

typical of Phyllophaga

larvae. (Clemson 

University - USDA 

Cooperative Extension 

Slide Series, 

Bugwood.org)

Figure 5. Damage 

from adult Phyllophaga

species consists of 

defoliation, usually 

on hardwoods, but 

sometimes on conifers. 

(Top: Darren Blackford, 

USDA Forest Service, 

Bugwood.org; bottom: 

Whitney Cranshaw, 

Colorado State 

University, 

Bugwood.org)
304 Forest Pest Insects in North America:

Images of May and

June Beetles (continued)

Figure 6. The most important damage from Phyllophaga species as forest pests 

is death of seedlings or small trees whose roots are eaten by larvae in the soil. 

Here, pine seedings whose roots have been eaten by Phyllophaga larvae. 

(W.H. Bennett, USDA Forest Service, Bugwood.org)

Parasitoids of May and June beetles include wasps in the genus Tiphia

(Tiphiidae), especially Tiphia inornata (Say), as well as several species 

of tachinid parasitoids such as Microphthalma disjuncta Wiedman. 

Grubs of Phyllophaga species are also attacked in the soil by various 

bacteria, fungi and nematodes, some of which have been formulated as 

biopesticides with varying levels of success in practical use. 

http://www.ag.ndsu.nodak.edu/aginfo/entomology/entupdates/whitegrub/

whitgrub.htm; fact sheet of the North Dakota State University of 

prevention and management of white grub damage.

http://en.wikipedia.org/wiki/Phyllophaga_(genus); Wikipedia article 

providing overview of white grubs in the genus Phyllophaga.

http://www.unl.edu/museum/research/entomology/Guide/Scarabaeoidea/

Scarabaeidae/Melolonthinae/Melolonthinae-Generic-pages/Melolonthini/

Phyllophaga/Phyllophaga.html; a guide to New World scarab genera, 

including profiles of several Phyllophaga species. 

http://www.freshfromflorida.com/pi/enpp/ento/scarab-pest-alert.html; 

two pest Phyllophaga species newly invasive in Florida.

http://www.forestpests.org/nursery/whitegrubs.html; USDA Forest 

Service fact sheet on white grubs as pests in forest nurseries.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on May and June Beetles
A Photographic Guide 305

Luginbill, P. and H.R. Painter. 1953. May beetles of the United States 

and Canada. U.S. Department of Agriculture Technical Bulletin 

No. 1060: 102 p.

Ives, W.G.H. and G.L. Warren. 1965. Sequential sampling for white 

grubs. The Canadian Entomologist 97: 596-604.

Ritcher, P.O. 1966. White grubs and their allies. A study of North 

American scarabaeoid larvae. Oregon State Monographs, Studies in 

Entomology No. 4: 214 p.

Fowler, R.F. and L.F. Wilson. 1971. White grub populations, 

Phyllophaga spp. in relation to damaged red pine seedlings in Michigan 

and Wisconsin plantations (Coleoptera: Scarabaeidae). Michigan 

Entomologist 4: 23-28.

Liesch, P.J. and R.C. Williamson. 2010. Evaluation of chemical controls 

and entomopathogenic nematodes for control of Phyllophaga white 

grubs in a Fraser fir production field. Journal of Economic Entomology

103: 1979-1987.

Articles
306 Forest Pest Insects in North America:

86. Black Vine Weevil, Otiorhynchus sulcatus (Fabricius) (Coleoptera: 

Curculionidae) 

Orientation to Pest The black vine weevil, Otiorhynchus sulcatus (Fabricius), is a weevil that 

is likely native to some or all of Europe that has invaded North America, 

Japan, New Zealand, Australia, and parts of southern South America. The 

mechanism of these invasions has been movement of the insect in balled 

nursery stock plants. This species feeds on over 100 species of plants. 

Larvae are the main damaging stage, feeding in the soil on plant roots. 

Young larvae eat the fine roots, but the following year, mature larvae 

destroy the larger roots as well. Unlike the white grubs of scarabs such 

as Japanese beetle (Popillia japonica Newman), weevil larvae such as 

those of black vine weevil, are less C-shaped and lack legs. Adults feed 

at night, notching the leaves of their host plants, but damage from adult 

feeding is not severe. Leaf notching is, however, a useful indicator of 

the presence of this nonflying, nocturnal insect whose larvae are out of 

sight in the soil. The most common overwintering stage of this insect is 

the young larva, but sometimes adults too overwinter. In general, in the 

eastern United States, adults emerge in June. Black vine weevils are pests 

in greenhouses and forestry nurseries where planting stock is produced, 

to both potted and field-grown plants. 

Plants fed on by black vine weevil include many woody and non-woody 

species, including strawberry (Fragaria), yew (Taxis), spruce (Picea), 

hemlock (Tsuga), rhododendron (Rhododendron), grape (Vitis), and 

cyclamen (Cyclamen). 

The black vine weevil is found in the northeastern and north central 

parts of the United States and adjacent parts of eastern Canada, and from 

Alaska south to California. 

Hosts Commonly Attacked

Distribution

Images of 

Black Vine Weevil

Figure 1. Adults of black vine weevil, Otiorhynchus sulcatus, are flightless (wing 

covers do not open) and nocturnal. (Left: Kent Loeffler, Cornell University, 

Bugwood.org; right: Cheryl Moorehead, individual, Bugwood.org)
A Photographic Guide 307

Images of Black

Vine Weevil (continued)

Figure 2. Larvae of black vine weevil are cream colored, with a brown head and 

no legs. (Left: Peggy Greb, USDA Agricultural Research Service, Bugwood.org; 

right: Mike Reding and Betsy Anderson, USDA Agricultural Research Service, 

Bugwood.org)

Figure 3. Pupae of black vine weevil occur naked in the soil. (Left: Mike Reding 

and Betsy Anderson, USDA Agricultural Research Service, Bugwood.org; 

right: Jim Baker, North Carolina State University, Bugwood.org)

Figure 4. Adult black vine weevils notch edges of host leaves (left, sedum plants 

and right, rhododendrons). (Left: Mike Reding and Betsy Anderson, USDA 

Agricultural Research Service, Bugwood.org; right: Jim Baker, North Carolina 

State University, Bugwood.org)
308 Forest Pest Insects in North America:

Images of Black

Vine Weevil (continued)

Figure 5. Damage to 

yew seedling roots from 

black vine weevil larvae. 

(Jim Baker, 

North Carolina 

State University, 

Bugwood.org)

Specialized parasitoids or predators of this species have not been 

reported. Most attention has been on various species of nematodes 

(e.g., Heterorhabditis heliothidis [Kahn, Brooks, and Hirschman]) and 

fungal entomopathogens (e.g., Metarhizium anisopliae [Metchnikoff] 

Sorokin), which have been developed for use as biopesticides against this 

species with varying degrees of success depending on such things as soil 

temperature.

http://woodypests.cas.psu.edu/factsheets/insectfactsheets/html/black_

vine_weevil.html; fact sheet of Pennsylvania State University.

http://www.umassgreeninfo.org/fact_sheets/root_shoot_feeders/black_

vine_weevil.html; fact sheet of the University of Massachusetts. 

http://www.coopext.colostate.edu/TRA/PLANTS/blackvine.shtml; fact 

sheet of the Colorado State University.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Black Vine Weevil
A Photographic Guide 309

Haukeland, S. and T. Lola-Luz. 2010. Efficacy of the entomopathogenic 

nematodes Steinernema kraussei and Heterorhabditis megidis against the 

black vine weevil Otiorhynchus sulcatus in open field-grown strawberry 

plants. Agricultural and Forest Entomology 12(4): 363-369.

Ansari, M.A., F.A. Shah, and T.M. Butt. 2008. Combined use of 

entomopathogenic nematodes and Metarhizium anisopliae as a new 

approach for black vine weevil, Otiorhynchus sulcatus, control. 

Entomologia Experimentalis et Applicata 129: 340-347.

von Reibnitz, C. and G.F. Backhaus. 1992. Analysis of the incidence and 

control of Otiorhynchus sulcatus in tree nurseries. Results from a survey 

in Lower Saxony and Schleswig-Holstein. Gesunde Pflanzen 45(2): 

54-60. (In German).

Articles
310 Forest Pest Insects in North America:

87. Strawberry Root Weevil, Otiorhynchus ovatus (L.) (Coleoptera: 

Curculionidae)

Orientation to Pest The strawberry root weevil, Otiorhynchus ovatus (L.), is invasive 

in North America. It is polyphagous, and larvae feed on plant roots, 

while adults feed nocturnally on the foliage, buds and young shoots 

of a wide range of host plants. Adults do not fly and all are females. 

Unlike white grubs (larvae of scarabs), weevil larvae such as those 

of strawberry root weevil are less C-shaped and lack legs. Black vine 

weevil, Otiorhynchus sulcatus (Fabricius), is a similar appearing species, 

but whose larvae are much larger than those of strawberry root weevil. 

In Oregon, strawberry root weevil overwinters as partially grown larvae 

or as adults. Adults emerge in late May and early June and begin laying 

eggs about two weeks later. Larvae feed from September through April 

of the following year and cause the most damage from late March to 

mid-May. Strawberry root weevil is a forestry pest only in the context of 

forest nurseries, where infestations may build up. Larvae feed on roots 

of tree seedlings and can be controlled by soil applications of chemical 

insecticides, nematodes, or entomopathogenic fungi. 

Adult beetles feed on foliage, especially of arborvitae (Thuja). The larvae 

feed on the roots of hemlock (Tsuga) and various other conifers, such as 

spruce (Picea), pine (Pinus), yew (Taxus), and arborvitae, as well as a 

variety of agricultural crops. 

The strawberry root weevil is found in most parts of the United States 

and southern Canada.

Hosts Commonly Attacked

Distribution

Images of 

Strawberry Root Weevil

Figure 1. Adult of strawberry root weevil, Otiorhynchus ovatus. (Left: Pest and 

Diseases Image Library, Bugwood.org; right: Whitney Cranshaw, Colorado State 

University, Bugwood.org)
A Photographic Guide 311

Images of Strawberry

Root Weevil (continued)

Figure 2. Larva of 

strawberry root weevil. 

(Russell Karow, Oregon 

State University)

Figure 3. Pupa of 

strawberry root weevil. 

(Russell Karow, Oregon 

State University)

Figure 4.Girdling of bare root 

spruce seedling by adults of 

strawberry root weevil. (Natural 

Resources Canada, Canadian 

Forest Service)
312 Forest Pest Insects in North America:

Important Biological Control 

Agents Related to this 

Pest Species

The only parasitoid known to attack this species in North America 

is the braconid Triaspis kurtogaster Martin, but that parasitoid’s 

importance in controlling populations of the weevil is unknown. Various 

entomopathogenic fungi have been found attacking larvae of strawberry 

root weevil, such as Isaria fumosorosea Wize (Ifr.) (formerly known as 

Paecilomyces fumosoroseus [Wize] Brown and Smith) and Metarhizium 

anisopliae (Metchnikoff) Sorokin. Various nematodes also attack larvae 

of this species, Heterorhabditis bacteriophora Poinar being the species 

most promising for control. Several species of both fungi and nematodes 

have been assessed as biopesticides against larvae of strawberry root 

weevil in various settings, including forest nurseries, cranberry bogs, and 

potted nursery stock in and around greenhouses. In general, control has 

been better in potted plants than open fields, and in warmer soils versus 

cold soils. Cool temperatures (11-14 °C) reduce efficacy of some species 

of nematodes. 

http://mint.ippc.orst.edu/srwfact.pdf; fact sheet of Oregon State 

University on biology and management.

http://whatcom.wsu.edu/ipm/manual/rasp/weevil.html; fact sheet of 

Washington State University comparing several species in the genus 

Otiorhynchus.

http://www.pfc.cfs.nrcan.gc.ca/diseases/nursery/pests/rootweev_e.html; 

fact sheet of Natural Resources Canada discussing root weevils as pests 

in forest nurseries.

Nielsen, D.G. 1989. Minimizing Otiorhynchus root weevil impact in 

conifer nurseries. In: Alfaro, R.I. and S.G. Glover (eds.). Proceedings 

of Conference: Insects affecting reforestation: biology and damage.

Forestry Canada, Pacific and Yukon Region, Victoria, British Columbia: 

71-79. 

Vainio, A. and H.M.T. Hokkanen. 1993. The potential of 

entomopathogenic fungi and nematodes against Otiorhynchus ovatus

L. and O. dubius Ström (Col., Curculionidae) in the field. Journal of 

Applied Entomology 115(4): 379-387.

Berry, R.E., J. Liu, and E. Groth. 1997. Efficacy and persistence of 

Heterorhabditis marelatus (Rhabditida: Heterorhabditidae) against 

root weevils (Coleoptera: Curculionidae) in strawberry. Environmental 

Entomology 26: 465-470.

Web Links for Information 

on Strawberry Root Weevil

Articles
A Photographic Guide 313

88. Japanese Beetle, Popillia japonica Newman (Coleoptera: Scarabaeidae) 

Orientation to Pest The Japanese beetle, Popillia japonica Newman, is an invasive insect 

in North America (United States and Canada) that is native to Japan. 

It is also invasive in China, Russia and Portugal. Adults fly during 

the summer and may occur in large numbers, defoliating raspberries, 

strawberries, roses, grapes, and other plants. Adults burrow into the soil, 

especially in grassy areas, and lay eggs several inches underground, 

where larvae then develop, feeding on the roots of grass plants and 

damaging the turf. There is usually one generation per year and partly 

grown larvae in the soil are the overwintering stage.

Adults defoliate a wide range of plants including grapes, roses, and 

various shade and fruit trees. Larvae eat the roots of grasses and are 

major pests of turf, especially on golf courses. Larvae can be pests in tree 

nurseries or on ornamental nursery stock.

In North America, the Japanese beetle is found in most states east of 

the Mississippi River and the invaded area continues to expand. One 

important pathway by which this pest is spread is the movement of larvae 

in nursery stock shipped with soil. The beetle is not found in California 

or the Pacific Northwest states. 

Hosts Commonly Attacked

Distribution

Images of 

Japanese Beetle

Figure 1. Adult Japanese beetle, Popillia japonica. (David Cappaert, Michigan 

State University, Bugwood.org)
314 Forest Pest Insects in North America:

Images of Japanese

Beetle (continued)

Figure 2. Larva of the Japanese beetle (left); three species of “white grubs” 

(right) to show relative size, from left to right: Japanese beetle, European chafer 

(Rhizotrogus majalis [Razoumowsky]), and June beetle (Phyllophaga sp.). 

(Both photos: David Cappaert, Michigan State University, Bugwood.org)

Figure 3. The V-shaped pattern of the “raster” (a group of hairs on underside of 

the rear tip of larval body) is used to identify larvae of Japanese beetles. 

(Mike Reding and Betsy Anderson, USDA Agricultural Research Service, 

Bugwood.org; inset: Clemson University, Cooperative Extension Fact Sheet)

Figure 4. Adult Japanese beetles feeding on rose flower (left) and foliage of other 

plants (right). (Left: Clemson University - USDA Cooperative Extension Slide 

Series, Bugwood.org; right: Ronald S. Kelley, Vermont Department of Forests, 

Parks and Recreation, Bugwood.org)
A Photographic Guide 315

Images of Japanese

Beetle (continued)

Figure 5. Turf infested by Japanese beetle larvae and then dug up by skunks or 

other mammals to eat grubs. (M.G. Klein, USDA Agricultural Research Service, 

Bugwood.org)

A large scale effort to achieve biological control of this pest, based 

on searching for natural enemies in Japan and China, was made in the 

1920s and 1930s. Several parasitoids were imported and established, 

the most important of which were three tachinid flies (especially 

Istocheta aldrichi [Mesnil]) and several tiphiid wasps (especially Tiphia 

popilliavora Rohwer and Tiphia vernalis Rohwer). Several pathogens 

of this beetle were also discovered and attempts were made to turn them 

into biopesticides. These included the bacterium that causes milky spore 

disease (Paenibacillus popilliae [Dutky]) and the nematode Steinernema 

glaseri (Steiner). It was the study of this nematode that stimulated the 

development of this family of nematodes as successful biopesticides 

against soil insects. For a detailed history of the biological control efforts 

against Japanese beetle, see Van Driesche et al. (1996).

http://en.wikipedia.org/wiki/Japanese_beetle; Wikipedia article on 

biology and control.

http://edis.ifas.ufl.edu/in630; fact sheet of the University of Florida, 

discussing biology and control.

http://www.aphis.usda.gov/publications/plant_health/content/printable_

version/jbidcard5-07.pdf; USDA fact sheet including a life cycle 

diagram.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Japanese Beetle
316 Forest Pest Insects in North America:

Van Driesche, R.G., S. Healy, and R.C. Reardon. Biological Control 

of Arthropod Pests of the Northeastern and North Central Forests 

in the United States: A review and recommendations. FHTET-96-19. 

USDA Forest Service, Morgantown, West Virginia: 43-48. (Available 

at http://www.forestpestbiocontrol.info/fact_sheets/documents/

arthropodpestsnortheastern_northcentral.pdf).

Power, K.T., R.S. An, and P.S. Grewal. 2009. Effectiveness of 

Heterohabditis bacteriophora strain GPS11 applications targeted against 

different instars of the Japanese beetle Popillia japonica. Biological 

Control 48: 232-236.

Oliver, J.B., M.E. Reding, N.N. Youssef, M.G. Klein, B.L. Bishop, and 

P.A. Lewis. 2009. Surface-applied insecticide treatments for quarantine 

control of Japanese beetle, Popillia japonica Newman (Coleoptera: 

Scarabaeidae), larvae in field-grown nursery plants. Pest Management 

Science 65: 381-390.

Articles on 

Japanese Beetle
A Photographic Guide 317

89. Twolined Chestnut Borer, Agrilus bilineatus (Weber) (Coleoptera: 

Buprestidae) 

Twolined chestnut borer, Agrilus bilineatus (Weber), is native to North 

America and occurs throughout southeastern Canada and the eastern 

and central United States. Adults are recognizable as dark colored 

buprestids with two golden stripes running lengthwise along their back. 

Adult beetles fly from April to August, depending on the location, and 

there is one generation per year. In Michigan and surrounding areas, 

adult emergence peaks in mid-to late June. Females lay eggs in small 

clusters in bark cracks and crevices. Newly hatched larvae burrow into 

the tree and form feeding galleries under the bark. Larvae are light 

colored and up to 2.5 cm long when mature, and have two spines at the 

tip of the abdomen, as is typical for all Agrilus larvae. Larvae construct 

meandering galleries that are packed tightly with feces mixed with boring 

dust. These feeding galleries interrupt the transport of food and water 

in the phloem (inner bark) and xylem (outer sapwood) and eventually 

girdle individual branches or the entire tree. Attacks occur in stressed or 

dying chestnut (Castanea dentata [Marsh.] Borkh.) or oak (Quercus). 

Live healthy trees are typically not infested. Attacks usually begin in the 

crown of the tree, with some branches dying in the first year. Infestations 

progress downward, and the trees usually die in the second or third 

year. Incidence of attack by twolined chestnut borer increases following 

stress such as drought or defoliation from insects such as gypsy moth 

(Lymantria dispar [L.]). 

American chestnut (C. dentata) and various species of oak, especially 

white (Quercus alba L.), scarlet (Q. coccinea Muenchh.), northern pin 

(Q. ellipsoidalis E. J. Hill), bur (Q. macrocarpa Michx.), chestnut 

(Q. prinus L.), northern red (Q. rubra L.), post (Q. stellata Wangenh.), 

black (Q. velutina Lamb.), and live (Q. virginiana Miller) oaks are hosts 

of twolined chestnut borer.

Twolined chestnut borer is 

widespread in the eastern 

and central United States 

and southeastern Canada. 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Figure 1. Probable range of 

the twolined chestnut borer, 

Agrilus bilineatus, based on 

the combined distribution of 

its oak host species. (USDA 

Forest Service • Forest Insect 

and Disease Leaflet 168)
318 Forest Pest Insects in North America:

Images of Twolined

Chestnut Borer

Figure 2. Adult of twolined chestnut borer, showing the two golden stripes along 

the back. (Robert A. Haack, USDA Forest Service, Bugwood.org)

Figure 3. Larvae of twolined chestnut borer in galleries (left) and close up of larva 

(right), showing the two projections from the rear end of the body (found in all 

Agrilus species). (Left: James Solomon, USDA Forest Service, Bugwood.org; 

right: Robert A. Haack, USDA Forest Service, Bugwood.org)

Figure 4. The exit hole of the twolined chestnut 

borer, like that of other species of Agrilus, is D 

shaped rather than round or oval. (USDA Forest 

Service • Forest Insect & Disease Leaflet 168)

Figure 5. View of the long winding larval galleries of twolined chestnut borer. 

(Minnesota Department of Natural Resources Archive, Minnesota Department of 

Natural Resources, Bugwood.org)
A Photographic Guide 319

Images of Twolined

Chestnut Borer (continued)

Figure 6. The earliest 

signs of twolined 

chestnut borer attack 

are wilting of foliage in 

later summer and then 

death of upper limbs of 

tree. (Steven Katovich, 

USDA Forest Service, 

Bugwood.org)

Figure 7. Phasgonophora sulcata is a 

common larval parasite of the twolined 

chestnut borer in Wisconsin. (USDA 

Forest Service • Forest Insect & Disease 

Leaflet 168)

Larval parasites provide limited natural control of the twolined chestnut 

borer. One larval parasite, the chalcid wasp Phasgonophora sulcata

Westwood, causes up to 10 percent larval mortality.

http://www.na.fs.fed.us/spfo/pubs/fidls/chestnutborer/chestnutborer.htm; 

USDA Forest Service Forest Insect and Disease Leaflet No. 168.

Dunbar, D.M. and G.R. Stephens. 1976. The bionomics of the twolined 

chestnut borer. In: Anderson, J.F. and H.K. Kaya (eds.) Perspectives in 

Forest Entomology. New York, New York. Academic Press: 73-83. 

Cote, W.A., III and D.C. Allen. 1980. Biology of twolined chestnut 

borer, Agrilus bilineatus, in Pennsylvania and New York. Annals of the 

Entomological Society of America 73: 409-413. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Twolined Chestnut Borer

Articles
320 Forest Pest Insects in North America:

Haack, R.A., D.M. Benjamin, and B.A. Schuh. 1981. Observations on 

the biology of Phasgonophora sulcata (Hymenoptera: Chalcididae), 

a larval parasitoid of the twolined chestnut borer, Agrilus bilineatus

(Coleoptera: Buprestidae), in Wisconsin. The Great Lakes Entomologist

14: 113-116. 

Haack, R.A. and D.M. Benjamin. 1982. The biology and ecology of the 

twolined chestnut borer, Agrilus bilineatus (Coleoptera: Buprestidae), 

on oaks, Quercus spp., in Wisconsin. The Canadian Entomologist 114: 

385-396. 

Dunn, J.P., T.W. Kimmerer, and G.L. Nordin. 1986. The role of host tree 

condition in attack of white oaks by the twolined chestnut borer, Agrilus 

bilineatus (Weber) (Coleoptera: Buprestidae). Oecologia 70: 596-600. 

Muzika, R.M., A.M. Liebhold, and M.J. Twery. 2000. Dynamics of 

twolined chestnut borer, Agrilus bilineatus, as influenced by defoliation 

and selection thinning. Agricultural and Forest Entomology 2: 

283-289. (Available at http://onlinelibrary.wiley.com/doi/10.1046/j.1461-

9563.2000.00077.x/pdf). 

Articles (continued)
A Photographic Guide 321

90. Bronze Birch Borer, Agrilus anxius Gory (Coleoptera: Buprestidae) 

Orientation to Pest Bronze birch borer, Agrilus anxius Gory, adults are slender, olivebronze beetles, with a coppery reflection. The species is native to North 

America and is widespread in the eastern and central United States 

and southeastern Canada. Before 1950, bronze birch borer and another 

species, now called aspen borer (Agrilus liragus Barter and Brown) were 

considered to be the same species; so records from before this period 

need to be segregated based on the genus of tree attacked, with only 

Betula-attacking records being bronze birch borer. The biology of this 

species is similar to that of other Agrilus species, with adults emerging 

in late spring or early summer, laying eggs in bark cracks or under bark 

flaps, and larvae tunneling through the bark to the phloem and cambium 

layers, where they construct and feed in long meandering galleries. 

Full-grown larvae construct shallow cells in the xylem (outer sapwood) 

in autumn where they overwinter. They pupate the following spring 

and adults emerge shortly thereafter. There is usually one generation 

per year, but it may require two years to reach maturity in some areas. 

Bronze birch borer develops in weakened trees of various species of 

birch (Betula), especially the white-barked species. Individual branches 

or entire trees are killed by the girdling action of the larvae. Bronze 

birch borer is considered the most serious pest of paper birch (Betula 

papyrifera Marsh.) and extensive outbreaks occurred in New Brunswick 

in 1939 and in the Great Lakes states in the 1990s. In both cases, 

outbreaks were in large stands of older birch trees stressed by defoliating 

insects or drought. Bronze birch borer may attack healthy trees during 

outbreaks, especially isolated trees, and ones on the edges of clearings. 

Ornamental birches, especially those of Asian and European origin, are 

often highly susceptible to bronze birch borer attack. 

Species that are severely attacked include European white birch 

(B. pendula Roth) and whitebarked Himalayan birch (B. jacquemontii D. 

Don). Commonly attacked species include paper birch (B. papyrifera), 

gray birch (B. populifolia Marsh.), sweet birch (B. lenta L.), and yellow 

birch (B. alleghaniensis Britt.).

Bronze birch borer occurs across Canada from Newfoundland to British 

Columbia and south to New Jersey, Ohio, Colorado, Idaho, and Utah in 

the United States. 

Hosts Commonly Attacked

Distribution
322 Forest Pest Insects in North America:

Images of 

Bronze Birch Borer

Figure 1. Adult bronze birch borer, Agrilus anxius. (John A. Weidhass, Virginia 

Polytechnic Institute and State University, Bugwood.org)

Figure 2. Larva of bronze birch borer. (Whitney Cranshaw, Colorado State 

University, Bugwood.org)

Figure 3. Larval galleries 

of bronze birch borer 

in a limb (top) and the 

trunk (bottom). (Top: 

William M. Ciesla, Forest 

Health Management 

International, 

Bugwood.org; bottom: 

Whitney Cranshaw, 

Colorado State 

University, Bugwood.org)
A Photographic Guide 323

Images of Bronze 

Birch Borer (continued)

Figure 4. Mature larvae tunnel a short way into the wood (left) to overwinter 

and pupate in spring; right, pupa of bronze birch borer in outer sapwood. (Left: 

E. Bradford Walker, Vermont Department of Forests, Parks and Recreation, 

Bugwood.org; right: Jim Baker, North Carolina State University, Bugwood.org)

Figure 5. D-shaped 

exit hole made by adult 

bronze birch borer. 

(Whitney Cranshaw, 

Colorado State 

University, Bugwood.org)

Figure 6. Landscape trees with infestations of bronze birch borer. (Left: Steven 

Katovich, USDA Forest Service, Bugwood.org; right: Randy Cyr, Greentree, 

Bugwood.org)
324 Forest Pest Insects in North America:

Images of Bronze 

Birch Borer (continued)

Figure 7. Damage from bronze birch borer in a forest birch stand in Minnesota. 

(USDA Forest Service - Northeastern Area Archive, USDA Forest Service, 

Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

Natural enemies of bronze birch borer have been studied in New 

Brunswick and Pennsylvania. Egg parasitism by several species (the 

signiphorid Thysanus sp. and the encrytid Coccidencyrtus sp.) was 

common (about 50 percent) and was considered important. Important 

larval parasites included the braconid Atanycolus charus (Riley) and the 

chalcidid Phasgonophora sulcata Westwood, which together killed about 

18 percent of the larvae. 

http://ipm.illinois.edu/landturf/insects/bronze_birch_borer/index.html; 

IPM fact sheet from Illinois.

http://www.na.fs.fed.us/spfo/pubs/fidls/bbb/bbb.htm; USDA Forest 

Service Forest Insect & Disease Leaflet 111.

http://wiki.bugwood.org/Agrilus_anxius; Bugwood Wiki fact sheet.

http://www.eppo.org/QUARANTINE/Alert_List/insects/agrilus_anxius.

htm; EPPO fact sheet on risk of bronze birch borer as a potential risk for 

invasion to Europe.

http://www.eppo.org/QUARANTINE/Pest_Risk_Analysis/PRA_

documents.htm; EPPO fact sheet on risk of bronze birch borer to 

European birches.

Web Links for Information 

on Bronze Birch Borer
A Photographic Guide 325

Anderson, R.F. 1944. The relation between host condition and attacks by 

the bronze birch borer. Journal of Economic Entomology 37: 588-596. 

Barter, G.W. 1957. Studies of the bronze birch borer, Agrilus anxius

Gory, in New Brunswick. The Canadian Entomologist 89: 12-36. 

Ball, J. and G. Simmons. 1980. The relationship between bronze birch 

borer and birch dieback. Journal of Arboriculture 6: 309-314. 

Akers, R.C. and D.G. Nielsen. 1984. Predicting Agrilus anxius Gory 

(Coleoptera: Buprestidae) adult emergence by heat unit accumulation. 

Journal of Economic Entomology 77: 1459-1463.

Jones, E.A., D.D. Reed, G.D. Mroz, H.O. Liechty, and P.J. Cattelino. 

1993. Climate stress as a precursor to forest decline: paper birch in 

northern Michigan, 1985-1990. Canadian Journal of Forest Research

23: 229-233.

Articles
326 Forest Pest Insects in North America:

91. Emerald Ash Borer, Agrilus planipennis Fairmaire (Coleoptera: 

Buprestidae) 

Orientation to Pest Emerald ash borer, Agrilus planipennis Fairmaire, is an invasive borer 

from northeast Asia threatening North American ash trees (Fraxinus). It 

was first detected near Detroit, Michigan and likely was introduced in 

the 1990s. It is now found in 14 other states and two Canadian provinces, 

and the infested range is expanding rapidly. Emerald ash borer attacks 

and kills healthy ash trees from ones several inches in diameter to 

mature trees. Massive mortality to ash of several species has occurred 

since the species’ invasion in both landscape plantings and natural ashdominated communities, especially in riparian areas. Larvae feed on 

phloem and make serpentine galleries that girdle and kill trees when the 

larval densities are high. Mature larvae tunnel into sapwood to pupate. 

In northern areas (e.g., Michigan), a single generation may require two 

years, but in mid-Atlantic states (e.g., Maryland), a generation can be 

completed each year. In dense populations, woodpeckers consume many 

larvae.

Most North American Fraxinus species are susceptible, but so far the 

most affected species have been white (Fraxinus americana L.), green 

(F. pennsylvanica Marshall), and black (F. nigra Marshall) ash. 

The North America infested area is centered on Michigan. Extensive 

infestations exist in Ontario, Illinois, Indiana, Ohio, Kentucky, 

Pennsylvania, and Maryland, and smaller infested areas are found in 

Quebec, Minnesota, Iowa, Wisconsin, Missouri, Tennessee, New York, 

Virginia, and West Virginia (as of 2010). 

Hosts Commonly Attacked

Distribution

Figure 1. Distribution of emerald ash borer, Agrilus planipennis, in 2010. 

(Cornell University, Cooperative Extension • The New York Invasive Species 

Clearinghouse)
A Photographic Guide 327

Images of 

Emerald Ash Borer

Figure 2. Adults of emerald ash borer. (Top left: Howard Russell, Michigan State 

University, Bugwood.org; top right and bottom: David Cappaert, Michigan State 

University, Bugwood.org)

Figure 3. Emerald ash 

borer eggs are white 

when freshly laid (top), 

but turn tan as they age 

(bottom). (Both photos: 

Houping Liu, Michigan 

State University, 

Bugwood.org)
328 Forest Pest Insects in North America:

Images of Emerald

Ash Borer (continued)

Figure 4. Feeding stage larvae of emerald ash borer: full grown 4th instar (left); 

second, third and 4th instars (right). (Both photos: David Cappaert, Michigan 

State University, Bugwood.org)

Figure 5. Larval galleries of emerald ash borer. (Top left: Troy Kimoto, Canadian 

Food Inspection Agency, Bugwood.org; top right: Michigan Department of 

Agriculture, Bugwood.org; bottom: Edward Czerwinski, Ontario Ministry of 

Natural Resources, Bugwood.org)
A Photographic Guide 329

Images of Emerald

Ash Borer (continued)

Figure 6. Prepupae in chambers formed in sap wood by mature larvae. (Brian 

Sullivan, USDA APHIS PPQ, Bugwood.org)

Figure 7. Prepupa of emerald ash borer in chamber in sap wood. (David 

Cappaert, Michigan State University, Bugwood.org)

Figure 8. D shaped emergence hole of emerald ash borer (left) and hole made 

by woodpecker (right) where an emerald ash borer larva was removed. (David 

Cappaert, Michigan State University, Bugwood.org)
330 Forest Pest Insects in North America:

Images of Emerald

Ash Borer (continued)

Figure 9. Signs of infestation: left, suckering; right, bark splits. (Left: Joseph 

O’Brien, USDA Forest Service, Bugwood.org; right: Michigan Department of 

Agriculture, Bugwood.org)

Figure 10. Dead and dying ash in forest area due to emerald ash borer. (Troy 

Kimoto, Canadian Food Inspection Agency, Bugwood.org)

Figure 11. Dying or dead landscape trees affected by emerald ash borer. (Left: 

Steven Katovich, USDA Forest Service, Bugwood.org; right: David Cappaert, 

Michigan State University, Bugwood.org)
A Photographic Guide 331

Images of Emerald

Ash Borer (continued)

Figure 12. Tree 

removal was tried, 

unsuccessfully, as a 

means to eradicate 

emerald ash borer 

populations. (Top: David 

Cappaert, Michigan 

State University, 

Bugwood.org; bottom: 

Daniel Herms, The 

Ohio State University, 

Bugwood.org)

Figure 13. Girdling trees can be an effective survey method to detect emerald 

ash borers. (Pennsylvania Department of Conservation and Natural Resources 

- Forestry Archive, Bugwood.org)
332 Forest Pest Insects in North America:

Images of Emerald

Ash Borer (continued)

Figure 14. The Chinese 

parasitoid of emerald 

ash borer eggs, Oobius 

agrili. (Debbie Miller, 

USDA Forest Service, 

Bugwood.org)

Figure 15. The Chinese 

larval parasitoid 

Tetrastichus planipennisi. 

(Houping Liu, Michigan 

State University, 

Bugwood.org)

Figure 16. The Chinese 

emerald ash borer larval 

parasitoid, Spathius 

agrili. (Jennifer Ayer, 

Bugwood.org)
A Photographic Guide 333

Images of Emerald

Ash Borer (continued)

Figure 17. Larva, pupa (in cocoon), and adult of the native North American 

parasitoid Atanycolus cappaerti Marsh and Strazanac. (Top and middle: 

David Cappaert, Michigan State University, Bugwood.org; bottom: Jian Duan, 

Bugwood.org)
334 Forest Pest Insects in North America:

Natural enemies of emerald ash borer that have been collected in 

the native range (especially in China and Russia) include two larval 

parasitoids (the eulophid Tetrastichus planipennisi Yang and the braconid 

Spathius agrili Yang), and an egg parasitoid, Oobius agrili Zhang and 

Huang (Hymenoptera: Encyrtidae). Additional parasitoids have been 

identified and are under consideration for importation, including Spathius

n. sp. and Antanycolus picipes Telenga from Russia. One group of native 

North American parasitoids, braconids in the genus Atanycolus, has 

adopted emerald ash borer and causes up to 20-40 percent mortality of 

the larvae in some areas.

http://www.invasiveforestinsectandweedbiocontrol.info/target_pests/

insects_mites/Emeraldashborer.htm; University of Massachusetts fact 

sheet on biological control of emerald ash borer.

http://www.nrs.fs.fed.us/disturbance/invasive_species/eab/control_

management/biological_control/; USDA Forest Service website on 

biological control of emerald ash borer.

http://www.dec.ny.gov/animals/7253.html; fact sheet of the New York 

Department of Environmental Conservation.

Liu, H-P, L.S. Bauer, D.L. Miller, L-W. Song, Q-S. Luan, S-H. Sun, 

and R.Z. Jin. 2007. Seasonal abundance and population dynamics of 

Agrilus planipennis (Coleoptera: Buprestidae) and its natural enemies 

Oobius agrili (Hymenoptera: Encyrtidae) and Tetrastichus planipennisi

(Hymenoptera: Eulophidae) in China. Biological Control 42: 61-71. 

Yang, Z-Q, J.S. Strazanac, P.M. Marsh, C. van Achterberg, and W-Y. 

Choi. 2005. First recorded parasitoid from China of Agrilus planipennis: 

A new species of Spathius (Hymenoptera: Braconidae, Doryctinae). 

Annals of the Entomological Society of America 98: 636-642.

Yang, Z-Q., J.S. Strazanac, Y-X. Yao, and X-Y. Wang. 2006. A new 

species of emerald ash borer parasitoid from China belonging to the 

genus Tetrastichus Haliday (Hymenoptera: Eulophidae) parasitizing 

emerald ash borer from China. Proceedings of the Entomological Society 

of Washington 108: 550-558.

Zhang,Y.Z., D.W. Huang, T.H. Zhao, H.P. Liu, and L.S. Bauer. 2005. 

Two new species of egg parasitoids (Hymenoptera: Encrytidae) of woodboring beetle pests from China. Phytoparasitica 33: 253-260.

Duan, J.J., L.S Bauer, J.R. Gould, and J.P. Lelito. 2011. Biological 

control of emerald ash borer in North America: Current progress and 

potential for success. IOBC Newsletter, November 2011.

Duan, J.J., L.S Bauer, K.J. Abell, and R.G. Van Driesche. 2011. 

Population responses of hymenopteran parasitoids to the emerald 

ash borer (Coleoptera: Buprestidae) in north central United States. 

BioControl 57: 199-209.

Web Links for Information 

on Emerald Ash Borer

Articles

Important Biological Control 

Agents Related to this 

Pest Species
A Photographic Guide 335

92. Goldspotted Oak Borer, Agrilus auroguttatus Schaeffer (Coleoptera: 

Buprestidae) 

Goldspotted oak borer, Agrilus auroguttatus Schaeffer, is an oakattacking buprestid native to mountains in southern Arizona. This pest 

invaded southern California, likely having been moved in firewood taken 

by campers into public campgrounds in the region. It has killed more 

than 80,000 oaks in California’s native oak-savannahs and is of concern 

as an ecological pest. It is still spreading due to unrestricted movement 

of firewood out of the affected parts of southern California, and the 

ultimate extent of potential damage is not yet known. The biology of this 

species is very similar to that of other Agrilus species, such as the better 

known emerald ash borer (Agrilus planipennis Fairmaire). In southern 

California, most goldspotted oak borers complete their development 

in one year, but some may require longer. Adults have an extended 

emergence period, but most do so in late June or early July. Adults have 

a pre-oviposition period during which they feed on oak foliage. Eggs are 

likely laid in crevices in the bark, and larvae after hatching bore through 

the bark. Young larvae feed in the outer phloem, while older larvae feed 

in the cambial layer. Pupation occurs in a chamber made by larvae in the 

outer phloem. Affected trees experience death of limbs, die back, and 

loss of vigor. Attacked trees often die within 2-3 years. 

The species most affected are coast live oak (Quercus agrifolia Née) 

and California black oak (Q. kelloggii Newb.). Canyon live oak (Q. 

chrysolepis Liebm.) is affected to a lesser degree. See http://en.wikipedia.

org/wiki/Agrilus_coxalis - cite_note-npag-0. 

Goldspotted oak borer occurs as a native species in southern Arizona and 

as an invader in southern California. A related species, now known as 

Agrilus coxalis Waterhouse, is native to southern Mexico and Guatemala. 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Figure 1. Known 

distribution of 

goldspotted oak borer, 

Agrilus auroguttatus, 

in California (invaded 

range-large circle) and 

Arizona (native rangesmall circles). (Tom 

Coleman, USDA Forest 

Service, Bugwood.org)
336 Forest Pest Insects in North America:

Images of 

Goldspotted Oak Borer

Figure 2. Adult goldspotted oak borer. (Mike Lewis, Center for Invasive Species 

Research, Bugwood.org)

Figure 3. Feeding larva of goldspotted oak borer, as seen in the larval gallery. 

(Mark S. Hoddle, University of California - Riverside, Bugwood.org)

Figure 4. Mature, “J”-shaped larva of goldspotted oak borer (see folded 

“hairpin” position of body). (Mark S. Hoddle, University of California - Riverside, 

Bugwood.org)
A Photographic Guide 337

Images of Goldspotted 

Oak Borer (continued)

Figure 5. Larval galleries of goldspotted oak borer under bark. (Tom Coleman, 

USDA Forest Service, Bugwood.org)

Figure 6. Wet stains on bark (left) caused by feeding of larvae, and scaled areas 

(right) where woodpeckers have removed larvae, are signs of goldspotted oak 

borer infestations. (Left: Tom Coleman, USDA Forest Service, Bugwood.org; 

right: Mark S. Hoddle, University of California - Riverside, Bugwood.org)
338 Forest Pest Insects in North America:

Images of Goldspotted 

Oak Borer (continued)

Figure 7. Exit holes of 

goldspotted oak borer 

have the “D”-shape 

typical of buprestids. 

(Mark S. Hoddle, 

University of California - 

Riverside, Bugwood.org)

Figure 8. Dead oaks in California oak-savannah due to attack by goldspotted oak 

borer. (Mike Lewis, Center for Invasive Species Research, Bugwood.org)

Figure 9. The eupelmid Calosota elongata, a larval ectoparasitoid of Agrilus 

auroguttatus (left, female; right, male). (Mike Lewis, Center for Invasive Species 

Research, Bugwood.org)
A Photographic Guide 339

Natural enemies of this species are relatively unknown, but surveys 

are being conducted in the pest’s native range in southern Arizona 

to discover species suitable for importation to California. To date, 

insects reared from logs infested with goldspotted oak borer have 

mostly been generalist predators or parasitoids use not suitable for use 

as classical biological control agents (for California). The euplemid 

Calosota elongata Gibson is a larval parasitoid, collected from 

Arizona, that appears to be more specialized and whose host range is 

under investigation. The same species has been found in California in 

association with goldspotted oak borer and may have been introduced 

along with its host. DNA studies are underway to compare the California 

population of C. elongata to ones in Arizona. No egg parasitoids are 

known. 

http://cisr.ucr.edu/goldspotted_oak_borer.html; University of California, 

Riverside, Center for Invasive Species Research article on goldspotted 

oak borer. 

http://en.wikipedia.org/wiki/Agrilus_coxalis; Wikipedia article, under a 

related but mistaken name of Agrilus coxalis.

http://ucanr.org/sites/SoCalOaks_NeedsAssessment2011/files/71253.pdf; 

bibliographic list of articles about goldspotted oak borer.

Coleman, T.W. and S.J. Seybold. 2008. New pest in California: The 

goldspotted oak borer, Agrilus coxalis Waterhouse. USDA Forest 

Service, Pacific Southwest Region, State and Private Forestry. Pest Alert 

R5-RP-022: 4 p. 

Hishinuma, S., T.W. Coleman, M.L. Flint, and S.J. Seybold. 2011. 

Gold-spotted oak borer field identification guide. University of 

California Agriculture and Natural Resources Statewide Integrated Pest 

Management Program: 6 p. (Available at http://www.ipm.ucdavis.edu/

PDF/MISC/GSOB_field-identification-guide.pdf). 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Goldspotted Oak Borer

Articles
340 Forest Pest Insects in North America:

93. Soapberry Borer, Agrilus prionurus Chevrolat (Coleoptera: Buprestidae) 

Orientation to Pest The soapberry borer, Agrilus prionurus Chevrolat, is a Mexican woodboring buprestid about which very little is known. It has moved out of 

its native range in Mexico into Texas, where it is now killing western 

soapberry trees (Sapindus saponaria var. drummondii [Hook. and 

Arn.] L.D. Benson). How it got to Texas is not known, but movement 

of firewood is a likely explanation. The biology of the insect is not 

well known but is likely very similar to other invasive Agrilus (e.g., 

goldspotted oak borer [A. auroguttatus Schaeffer] and emerald ash borer 

[A. planipennis Fairmaire]). The adults are about 1.3 cm long, black, 

with four distinctive white dots on the wing covers. The larvae feed 

immediately under the bark. While not certain, it is likely that the insect 

has one generation per year, with adults emerging between May and 

August. The insect probably overwinters as a mature larva or pupa in a 

cell in the wood of the soapberry trees, with adult beetles later emerging 

through a D-shaped exit hole and laying their eggs on the tree trunk. 

The only reported host in Texas is western soapberry (S. saponaria var. 

drummondii). Western soapberry trees larger than 5 cm in diameter at 

breast height are susceptible and infestation usually results in tree death 

within 1 to 3 years following initial attack. Hosts in Mexico have not 

been recorded. 

Native to Mexico, within the United States this species is currently found 

only in Texas in 42 counties.

Hosts Commonly Attacked

Distribution

Figure 1. Distribution of soapberry borer, Agrilus prionurus, in the United States. 

(USDA Forest Service • AFPE Online Mapping)
A Photographic Guide 341

Images of 

Soapberry Borer

Figure 2. Adults of soapberry borer. (Ronald F. Billings, Texas Forest Service, 

Bugwood.org)

Figure 3. Damage on 

the trunk (top) of a 

western soapberry tree 

from soapberry borer is 

highly visible, appearing 

as scaled patches where 

birds have picked off the 

bark in search of larvae, 

exposing galleries; larva 

visible in photo below. 

(Both photos: Ronald F. 

Billings, Texas Forest 

Service, Bugwood.org)
342 Forest Pest Insects in North America:

Images of Soapberry 

Borer (continued)

Figure 4. Emergence hole of the soapberry borer, showing typical “D” shape 

characteristic of buprestids. (Ronald F. Billings, Texas Forest Service, 

Bugwood.org)

Figure 5. Western 

soapberry tree showing 

branches killed by the 

soapberry borer and 

epicormic sprouts along 

lower trunk. (Ronald F. 

Billings, Texas Forest 

Service, Bugwood.org)
A Photographic Guide 343

Images of Soapberry 

Borer (continued)

Figure 6. Damage to group of western soapberry trees by soapberry borer in 

Houston, Texas. (Ronald F. Billings, Texas Forest Service, Bugwood.org)

Natural enemies of western soapberry borer are unknown. 

http://tfsweb.tamu.edu/main/popup.aspx?id=5316; fact sheet of the Texas 

Forest Service.

http://elpasonaturally.blogspot.com/2009/06/wanted-location-ofsoapberry-borer.html; website of “El Paso Naturally,” which includes 

photos of western soapberry borer. 

http://www.texasinvasives.org; website providing description of insect 

and questionnaire to report new infestations.

Wellso, S.G. and J.A. Jackman. 2006. A new species of Anthaxia

(Haplanthaxia) Reitter (Coleoptera: Buprestidae) and new North 

American buprestid distributional and host records. Pan-Pacific 

Entomologist 82(2): 262-268. (First record in the USA).

Billings, R.F. and H.A. Pase, III. 2010. Soapberry borer continues to 

spread in Texas. Texas Forestry, February issue: 7 p.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Soapberry Borer

Articles
344 Forest Pest Insects in North America:

94. Hickory Spiral Borer, Agrilus torquatus LeConte (Coleoptera: 

Buprestidae) 

Orientation to Pest Hickory spiral borer, Agrilus torquatus LeConte, is a native beetle found 

over a wide area in the eastern United States, feeding principally on 

pecan (Carya illinoinensis [Wangenh.] K. Koch) and hickory (other 

Carya spp.). There are a group of four closely species that previously 

were considered subspecies of Agrilus arcuatus, but all of which have 

now been raised to full species status, using their former subspecies 

names. These include A. arcuatus torquatus, the focus of this page, 

which attacks hickory and pecan; A. arcuatus fulgens from hazel 

(Corylus); A. arcuatus corylicola—also from hazel (Corylus); and A. 

arcuatus arcuatus from oak (Quercus) and American beech (Fagus 

grandifolia Ehrh.). Agrilus torquatus requires two growing seasons 

to complete its development, emerging in the spring or summer (May 

to July) of the third year. After emerging, adults feed on host foliage, 

making large irregular holes in the leaves. Eggs are deposited singly 

on the bark surface of terminals or lateral twigs, usually near the base 

of small shoots of the current season’s growth and are covered with a 

transparent secretion that glues them in place. Larvae tunnel beneath 

the bark, where they feed for two growing seasons. In late autumn, they 

begin spiral burrows, encircling the stem until reaching the center and 

severing the twigs by spring. Larvae pupate in cells constructed in the 

pith of the stem. The most distinctive aspect of the damage of this species 

is the spiral track made by the larvae, which is characteristic in form and 

good for identification of the pest. This track is a winding concentric 

gallery that moves from the inner bark to the heart of the branch or stem. 

Branches and terminals are usually severed in late winter or spring and 

the portion beyond the girdle typically dies before new foliage appears in 

spring, making damaged terminals easy to spot. Most severed branches 

break and fall to the ground around the time that buds open. Attacked 

twigs are usually from ca 1-4 cm in diameter and 0.5 to 2.5 m long. 

While most damage is to twigs and small branches, when seedlings 

are attacked they may be killed. Extensive damage to large pecan trees 

reduces nut production, and gives trees a ragged appearance. Repeated 

attacks on young trees may make them stunted, misshapen, or crooked.

The hosts of this species are pecan (C. illinoinensis) and species of 

hickory (Carya). 

This species has been recorded from New York, Ohio, North Carolina, 

and Mississippi.

Hosts Commonly Attacked

Distribution
A Photographic Guide 345

Images of 

Hickory Spiral Borer

Figure 1. Adult of the closely related Agrilus arcuatus. (Tom Murray, Bugwood.org)

Figure 2. Larva of hickory spiral borer Agrilus torquatus. (James Solomon, USDA 

Forest Service, Bugwood.org)

Figure 3. Distinctive spiraling pattern of larval galleries of hickory spiral borer. 

(James Solomon, USDA Forest Service, Bugwood.org)
346 Forest Pest Insects in North America:

Important Biological Control 

Agents Related to this 

Pest Species

Five insect parasitoids are known to attack this borer: Labena apicalis

Cresson, Labena grallator (Say), Monogonogastra agrili (Ashmead), 

Tetrastichus rugglesi Rohwer, and Zatropis sp. near nigroaeneus

(Ashmead).

None

Nelson, G.H. and H.A. Hespenheide. 1998. A re-evaluation of some 

Agrilus Curtis species (Coleoptera: Buprestidae). Coleopterists Bulletin

52(1): 31-34. 

Web Links for Information 

on Hickory Spiral Borer

Articles
A Photographic Guide 347

95. Flatheaded Appletree Borer, Chrysobothris femorata (Olivier) 

(Coleoptera: Buprestidae) 

Orientation to Pest Flatheaded appletree borer, Chrysobothris femorata (Olivier), is a 

common, well known native borer affecting many species of hardwood 

trees in North America. Adults emerge in summer and feed on foliage 

of their host trees. Eggs are deposited under bark scales or in crevices 

on the main trunk or larger branches. The larvae bore into the bark 

and feed in the phloem and outer sapwood. In older trees, tunnels are 

most often in the thick inner bark. Mature larvae build pupation cells in 

the outer wood in late summer, where they pass the winter and pupate 

the following spring. There is one generation per year. This borer is 

especially damaging to newly planted trees and trees stressed by drought 

or other factors. Young trees may be girdled and killed. Larger trees may 

show injuries through loss of large patches of bark on trunks. 

This species attacks a wide range of trees species, including sycamore 

(Platanus occidentalis L.), silver maple (Acer saccharinum L.), boxelder 

(A. negundo L.), black walnut (Juglans nigra L.), willow (Salix), 

white oak (Quercus alba L.), black oak (Q. velutina Lamb.), yellowpoplar (Liriodendron tulipifera L.), elm (Ulmus), American beech 

(Fagus grandifolia Ehrh.), hickory (Carya), hackberry (Celtus), apple 

(Malus domestica Borkh.), and pear (Pyrus). 

This species is found throughout most of Canada and the United States.

Hosts Commonly Attacked

Distribution

Images of Flatheaded

Appletree Borer

Figure 1. Adult of the flatheaded appletree borer, Chrysobothris femorata. 

(Joseph Berger, Bugwood.org)
348 Forest Pest Insects in North America:

Images of Flatheaded

Appletree Borer (continued)

Figure 2. Mature larva 

of flatheaded apple tree 

borer. (James Solomon, 

USDA Forest Service, 

Bugwood.org)

Figure 3. Sap spot 

over feeding site of 

flatheaded appletree 

borer larva in Nuttall oak 

(Quercus texana Buckl.). 

(James Solomon, 

USDA Forest Service, 

Bugwood.org)
A Photographic Guide 349

Images of Flatheaded

Appletree Borer (continued)

Figure 4. Damage to 

red maple (Acer rubrum

L.) from flatheaded 

appletree borer. (John 

Ruter, University of 

Georgia, Bugwood.org)

Natural enemies known to attack the flatheaded apple borer include 

the ichneumonids Labena grallator Say and Crytohelcostizus 

chrysobothridis Cushman, the chalcid Phasgonophora sulcata

Westwood, and the braconid Atanycolus rugosiventris Ashmead. 

Predators include the clerids Chariessa pilosa (Foster) and Chariessa 

pilosa onusta Say, the asilid Andrenosoma fulvicauda Say, and various 

woodpeckers.

http://insects.tamu.edu/extension/publications/epubs/eee_00027.cfm; fact 

sheet of the Texas A&M University covering biology and control.

http://ipm.illinois.edu/greenhouse/insects/flat_headed_apple_tree_borer/

index.html; fact sheet of the University of Illinois.

http://www.utextension.utk.edu/publications/spfiles/SP503-I.pdf; guide 

to the identification of apple flathead borer and other buprestids in 

Kentucky.

http://wiki.bugwood.org/Archive:Hickory/Chrysobothris_femorata; 

Bugwiki factsheet.

Potter, D.A., G.M. Timmons, and F.C. Gordon. 1988. Flatheaded apple 

treeborer (Coleoptera: Buprestidae) in nursery-grown red maples: 

phenology of emergence, treatment timing, and response to stressed 

trees. Journal of Environmental Horticulture 6(1): 18-22. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Flatheaded Appletree

Borer

Articles
350 Forest Pest Insects in North America:

96. Red Oak Borer, Enaphalodes rufulus (Haldeman) (Coleoptera: 

Cerambycidae) 

Orientation to Pest Red oak borer, Enaphalodes rufulus (Haldeman), is a native borer 

to North America, which attacks various species of oak (Quercus), 

primarily those in the red oak subgenus. Red oak borer has a 2-year life 

cycle that is unique in that adults only emerge during odd numbered 

years. Mating takes place on the host tree and females lay eggs in 

midsummer on roughened areas or near wounds, in bark crevices, or 

under lichen or vines. Young larvae bore through the bark and spend 

their first year in the phloem making small tunnels. The 2-year-old 

larvae enlarge these phloem galleries and then bore into the xylem where 

pupation takes place. The adult eventually emerges near the original 

oviposition site. Fine frass is one of the first signs of attack. As the larvae 

bore into the tree, wet spots can appear on the bark as sap oozes from the 

bore hole in the bark. Larval galleries increase in size over time, reaching 

1.5 cm in diameter. Tunnels are 15 to 25 cm long and penetrate directly 

through the oak xylem. Larval tunnels cause lumber cut from infested 

logs to be downgraded, reducing log value by up to 40 percent compared 

to top quality wood. 

This species attacks various oaks, including black (Quercus velutina

Lamb.), northern red (Q. rubra L.), and scarlet (Q. coccinea Muenchh.) 

oaks. 

Red oak borer is found throughout southern Canada and the eastern 

United States.

Hosts Commonly Attacked

Distribution

Images of 

Red Oak Borer

Figure 1. Adult of the red oak borer, Enaphalodes rufulus. (Jessica Lawrence, 

Eurofins Agroscience Services, Bugwood.org)
A Photographic Guide 351

Images of Red Oak

Borer (continued)

Figure 2. Eggs of red oak borer. (University of Arkansas Forest Entomology Lab 

Archive, University of Arkansas, Bugwood.org)

Figure 3. Young 1st-year red oak borer larva creating gallery in phloem. 

(University of Arkansas Forest Entomology Lab Archive, University of Arkansas, 

Bugwood.org)
352 Forest Pest Insects in North America:

Images of Red Oak

Borer (continued)

Figure 4. Late stage red 

oak borer larva in xylem 

gallery. (Fred Stephen, 

University of Arkansas)

Figure 5. Gallery of red oak borer. (Fred Stephen, University of Arkansas)

Figure 6. Galleries of older red oak borer larvae in the heart wood, seen in cross 

section. (University of Arkansas Forest Entomology Lab Archive, University of 

Arkansas, Bugwood.org)
A Photographic Guide 353

Images of Red Oak

Borer (continued)

Figure 7. Emergence holes of red oak borer. (University of Arkansas Forest 

Entomology Lab Archive, University of Arkansas, Bugwood.org)

Figure 8. Healed scars showing damage from red oak borer. (James Solomon, 

USDA Forest Service, Bugwood.org)

Figure 9. Lumber cut from infested trees is downgraded because of the galleries 

of red oak borer. (Joseph O’Brien, USDA Forest Service, Bugwood.org)
354 Forest Pest Insects in North America:

Images of Red Oak

Borer (continued)

Figure 10. View of trees killed by red oak borer. (Gerald J. Lenhard, Lousiana 

State Univ, Bugwood.org)

Figure 11. View of 

red oaks killed in the 

Arkansas Ozarks during 

outbreak, September 

2000. (Fred Stephen, 

University of Arkansas)

Parasitoids of this species are mostly generalists on wood borers and are 

not well known. Woodpeckers are an important predator of red oak borer 

larvae. 

http://www.eppo.org/QUARANTINE/Alert_List/insects/enaphalodes_

rufulus.htm; fact sheet of EPPO on red oak borer as a potential invasion 

threat to Europe.

Riggins, J.J., L.D. Galligan, and F.M. Stephen. 2009. Rise and fall of 

red oak borer (Coleoptera: Cerambycidae) in the Ozark mountains of 

Arkansas, USA. Florida Entomologist 92: 426-433.

Haavik, L.J. and F.M. Stephen. 2010. Historical dynamics of a native 

cerambycid, Enaphalodes rufulus, in relation to climate in the Ozark and 

Ouachita Mountains of Arkansas. Ecological Entomology 35: 673-683. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Red Oak Borer

Articles
A Photographic Guide 355

97. Black Fir Sawyer Beetle, Monochamus urussovii (Fischer von 

Waldheim) (Coleoptera: Cerambycidae) 

Orientation to Pest Black fir sawyer beetle, Monochamus urussovii (Fischer von Waldheim), 

is native to Eurasia and is not present in North America. Male black 

fir sawyer beetles have antennae approximately twice as long as body, 

whereas those of females are just a bit longer that the body. This beetle 

attacks all species in the family Pinaceae. Firs (Abies) are especially 

vulnerable to damage. It is the capability of M. urussovi to vector 

phytopathogenic fungi that poses the greatest threat to North American 

forests. Reproduction of this beetle occurs in weakened or dying trees 

that have been affected by drought or fire, or have been wind thrown or 

recently cut. Outbreaks can occur, however, in live, healthy trees. The 

life cycle begins when beetles feed in the crown, removing strips of bark. 

This feeding infects branches with the blue-stain fungus Leptographium 

sibiricum Jacobs and Wingfield. Dieback of branches in the crown 

weakens the tree and reduces resin flow. These changes make the 

tree suitable for beetle oviposition and larval feeding. In the summer, 

female beetles excavate oviposition niches, often in the branches, and 

lay a single egg beneath the bark. Larvae dig sinuous galleries, up to 

2.5 cm wide, under. These galleries are filled with frass. In the spring, 

overwintered larvae dig into the sapwood and create a pupal chamber, 

from which adults later emerge. As an infested host tree dies, its needles 

turn yellow and then red.

This species is most damaging to fir (Abies), but larch (Larix), spruce 

(Picea), pine (Pinus), and birch (Betula) species are also commonly 

attacked. 

This beetle occurs in Sweden, Norway, Finland, eastern Poland, Estonia, 

Latvia, Lithuania, Belarus, Ukraine, Russia, Kazakhstan, Mongolia, 

northeastern China, Korea, and northern Japan.

Hosts Commonly Attacked

Distribution

Images of Black Fir

Sawyer Beetle

Figure 1. Adult of 

black fir sawyer beetle, 

Monochamus urussovii. 

(Vitaly Gumenuk, 

Bugwood.org)
356 Forest Pest Insects in North America:

Images of Black Fir

Sawyer Beetle (continued)

Figure 2. The circular emergence holes of black fir sawyer beetles are large, 

ca 1.2 cm in diameter. (Stanislaw Kinelski, Bugwood.org)

Figure 3. Brown foliage 

is sign of attack by 

black fir sawyer beetle. 

(Stanislaw Kinelski, 

Bugwood.org)
A Photographic Guide 357

Some information is available in Russian language publications on the 

natural enemies of this species in Russia (see Isaev et al., 1988). 

http://www.inspection.gc.ca/english/plaveg/pestrava/monuru/tech/

monurue.shtml; fact sheet of Canadian food inspection agency, proving 

information on life history and damage.

Vetrova, V.P., A.S. Isaev, N.V. Pashenova, and N.Yu Konstantinov. 1998. 

Estimating the threat of a mass outbreak of Monochamus urussovii in 

the dark coniferous stands of the Lower Angara region after damage by 

Dendrolimus sibiricus. Lesovedenie 3: 58-67.

Jacobs, K., M.J. Wingfield, N.V. Pashenova, and V.P. Vetrova. 2000. 

A new Leptographium species from Russia. Mycological Research 104: 

1524-1529.

Isaev, A.S., T.M. Ovchinnikova, and V.G. Sukhovol’skii. 2001. Modeling 

the population dynamics of the longhorn Monochamus urussovii in the 

dark central-taiga forests of Siberia. Lesovedenie 4: 15-24.

Isaev, A.S., A.S. Rozhkov, and V.V. Kiselev. 1988. The fir longhorn 

Monochamus urussovi. (Chernyi pikhtovyi usach Monochamus urussovi

[Fisch.]). Novosibirsk: Nauka, No. 270. (In Russian)

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Black Fir Sawyer Beetle

Articles
358 Forest Pest Insects in North America:

98. Japanese Pine Sawyer, Monochamus alternatus Hope (Coleoptera: 

Cerambycidae)

Orientation to Pest Japanese pine sawyer, Monochamus alternatus Hope, is native to Asia, 

principally China, Japan and Korea. In Asia, this species has proven 

to be an important vector of an introduced pathogenic nematode, the 

pine wood nematode, Bursaphelenchus xylophilus (Steiner and Buhrer) 

Nickle, which kills Asian pines. Japanese pine sawyer is not yet present 

in the United States. Japanese pine sawyers overwinter as large larvae 

in galleries in infested trees. Pupation occurs at the end of winter, and 

adults emerge in spring and feed on foliage of hosts (termed maturation 

feeding). This feeding occurs on two-year old shoots of healthy trees. 

This feeding is important because it provides locations for nematode 

invasion of live healthy trees. Nematode larvae emerge from beetle 

spiracles, fall onto damaged twigs, and penetrate the woody tissue 

through the feeding wounds. Once mature, adult beetles lay their eggs 

in trees that are stressed or have recently been killed by bark beetles, 

lightening, disease, or other factors. Eggs are placed singly in slots in 

bark cut by females. Each female may lay 100-200 eggs. Young larvae 

feed in the cambium and mature larvae tunnel into the heartwood to 

complete the cycle. There is one generation per year. Infestations damage 

wood of recently dead and downed conifers, causing degradation and 

loss of value for lumber. 

The consequences of a potential introduction of Japanese pine sawyer 

to the United States by itself may not have severe consequences for 

two reasons. First, there are a number of other species of coniferinfesting Monochamus beetles already present in North America (e.g. 

M. caroliniensis, M. marmorator Kirby in Richardson, M. notatus

Drury, M. titillator Fabricius, M. scutellatus Say), all of which attack 

recently killed or severely stressed trees. If introduced and established in 

North America, Japanese pine sawyer would likely compete with these 

species for the same set of hosts. Secondly, the pine wood nematode, 

B. xylophilus, which is native to North America and is vectored by native 

Monochamus, does not kill North American conifers. However, an 

invasion of Japanese pine sawyer might also introduce an Asian species 

of Bursaphelenchus, such as Bursaphelenchus mucronatus (Mamiya and 

Enda) or Bursaphelenchus kolymensis Korentchenko, occur in Asia on 

species of Abies, Larix and Pinus (the former species has been found in 

Canada). These are not known to cause widespread mortality of their 

native hosts, but may be more pathogenic to some North American 

conifers, due to lack of evolutionary association and hence lack of 

selection for resistance. Such an effect is predicted by the damage caused 

to Asia conifers by an introduced American species of Bursaphelenchus. 

Detection of invasion must be based on collection and identification of 

adult beetles, as symptoms of infestation by M. alternatus are identical to 

those caused by native North American Monochamus species.
A Photographic Guide 359

Japanese pine sawyer is known to attack seventeen species of pines 

(Pinus), including, in Japan, Japanese red pine (Pinus densiflora Siebold 

and Zucc.), Japanese black pine (P. thunbergii Parl.), luchu pine 

(P. luchuensis Mayr), and, in China, Mason pine (P. massoniana

Lambert). It has also been reported to attack three species of spruce 

(Picea spp.), and one species each of fir (Abies), true cedar (Cedrus), 

and larch (Larix). Under laboratory conditions, fresh logs of the North 

American slash pine (Pinus elliottii Engelmann) were preferred over 

the native Japanese P. densiflora for oviposition, but larval survival 

was lower. 

Japanese pine sawyer is native to Asia and is found mainly in Japan, 

China, and Korea. 

Hosts Commonly Attacked

Distribution

Figure 1. World 

distribution of 

Japanese pine sawyer, 

Monochamus alternatus. 

(EPPO • EPPO Plant 

Quarantine Data 

Retrieval System [PQR])

Images of Japanese

Pine Sawyer

Figure 2. Adult of 

Japanese pine sawyer 

showing adult feeding 

on needles. (Jijing Song 

and Juan Shi, Beijing 

Forestry University, 

Bugwood.org)
360 Forest Pest Insects in North America:

Images of Japanese

Pine Sawyer (continued)

Figure 3. Various North 

American species are 

similar in appearance 

and biology to Japanese 

pine sawyer; for example, 

Monochamus notatus

(Drury) (top), Monochamus 

scuttelatus (Say) (middle), 

and Monochamus 

marmorator Kirby (bottom). 

(Top: J. Tomminen, 

University of Helsinki, 

Bugwood.org; middle: 

Laura Lazarus, North 

Carolina Division of Forest 

Resources, Bugwood.org; 

bottom: Natasha Wright, 

Florida Department of 

Agriculture and Consumer 

Services, Bugwood.org)
A Photographic Guide 361

Images of Japanese

Pine Sawyer (continued)

Figure 4. Adults of 

Japanese pine sawyer 

feed on foliage after 

emergence to obtain 

food to develop eggs. 

(William M. Ciesla, 

Forest Health 

Management 

International, 

Bugwood.org)

Figure 5. Egg of 

Japanese pine 

sawyer (top), and bark 

chewing at oviposition 

site (bottom). (Top: 

Jijing Song and Juan 

Shi, Beijing Forestry 

University, Bugwood.org; 

bottom: USDA Forest 

Service - North Central 

Research Station 

Archive, USDA Forest 

Service, Bugwood.org)
362 Forest Pest Insects in North America:

Images of Japanese

Pine Sawyer (continued)

Figure 6. Larva of 

Japanese pine sawyer. 

(Jijing Song and Juan 

Shi, Beijing Forestry 

University, Bugwood.org)

Figure 8. Tail of male 

pine wood nematode, 

Bursaphelenchus 

xylophilus, showing 

characteristic spicule. 

(L.D. Dwinell, USDA 

Forest Service, 

Bugwood.org)

Figure 7. Pupa of Japanese pine sawyer in the pupal chamber. The pupa is the 

stage that attracts the pine wood nematode, which attacks the trachea system 

of the pupa. (USDA Forest Service - Region 2 - Rocky Mountain Region Archive, 

USDA Forest Service, Bugwood.org)
A Photographic Guide 363

Images of Japanese

Pine Sawyer (continued)

Figure 9. Exit hole of 

Japanese pine sawyer 

(top), and adult exiting 

hole (bottom). (Top: 

Jijing Song and Juan 

Shi, Beijing Forestry 

University, Bugwood.org; 

bottom: USDA Forest 

Service - Region 2 - 

Rocky Mountain Region 

Archive, USDA Forest 

Service, Bugwood.org)

Figure 10. Mason pine (Pinus massoniana) in China killed by Japanese pine 

sawyer. (Jijing Song and Juan Shi, Beijing Forestry University, Bugwood.org)
364 Forest Pest Insects in North America:

Important Biological Control 

Agents Related to this 

Pest Species

In China, a recently recognized predator affecting Japanese pine 

sawyer is the Cryptalaus berus (Coleoptera: Elateridae), and in Japan, 

the predator Dastarcus helophoroides (Fairmaire) is believed to be an 

important source of mortality. 

http://spfnic.fs.fed.us/exfor/data/pestreports.cfm?pestidval=77&langdispl

ay=english; a web site of the USDA Forest Service, with extensive detail 

on biology and risks.

Kobayashi, F., A. Yamane, and T. Ikeda. 1984. The Japanese pine sawyer 

beetle as the vector of pinewood nematode disease. Annual Review of 

Entomology 29: 115-135.

Mota, M.M. and P. Vieira (eds.). 2008. Pine Wilt Disease: a Worldwide 

Threat to Forest Ecosystems. Springer, New York. 

Web Links for Information

on Japanese Pine Sawyer

Articles
A Photographic Guide 365

99. Asian Longhorned Beetle, Anoplophora glabripennis Motschulsky 

(Coleoptera: Cerambycidae)

Orientation to Pest Asian longhorned beetle, Anoplophora glabripennis Motschulsky, 

is native to Asia (principally China) and invasive in parts of western 

Europe, and in several American cities, where eradication efforts are 

underway. This borer attacks a variety of hardwood trees. In China, 

Asian longhorned beetles are not damaging in forests, but because of 

extensive planting of certain poplars (exotic varieties) that proved highly 

susceptible to the species, the insect increased in abundance. This action 

facilitated the beetle’s dissemination to other countries because infested 

wood was used for packing material. The biology of the species is typical 

of many longhorn beetles. Adults emerge over an extended period from 

spring to fall, but especially in late June to early July. Adults remain 

on or near their emergence tree and engage in maturation feeding on 

leaves, petioles, and tender bark. Eggs are laid singly under the bark, in 

egg sites chewed by females. Larvae feed in the cambium layer of the 

tree and later into the heartwood. Larvae dig pupation chambers inside 

the tree, which can be filled with frass. Adults emerge via large (1 cm 

dia) round exit holes, which are a visible sign of infestation. In southern 

Asia, a generation requires one year, but in northern areas, two years are 

required. Generations may be overlapping. Unlike many cerambycids, A. 

glabripennis attacks healthy trees as well as those under stress. Several 

generations can develop within an individual tree, eventually killing it. 

In China (the native range), the major hosts of A. glabripennis are 

certain species of Populus, especially Populus nigra L., P. deltoides

W. Bartram ex Marshall, Populus x canadensis and the Chinese hybrid 

P. dakhuanensis. Other important hosts are the willows Salix babylonica

L. and S. matsudana Koidzumi. Other species also recorded as hosts 

in China include species of Acer, Alnus, Malus, Morus, Platanus, 

Prunus, Pyrus, Robinia, Rosa, Sophora, and Ulmus. In urban areas in 

North America invaded by this species, the hosts attacked by this beetle 

have been species of maple (Acer negundo L., A. platanoides L., 

A. pseudoplatanus L., A. rubrum L., A. saccharinum L., and 

A. saccharum Marshall) and Aesculus hippocastanum L. However, it has 

also been found on a range of other hardwoods, including Liriodendron 

tulipifera L., Morus alba L., Robinia pseudacacia L., and species of 

Betula, Fraxinus, Populus, Salix, and Ulmus. 

Asian longhorned beetle is native to Asia. It has been detected in parts of 

Europe and in North America (Toronto, Canada, Illinois, the greater New 

York City area, New Jersey, and Massachusetts).

Hosts Commonly Attacked

Distribution
366 Forest Pest Insects in North America:

Images of Asian

Longhorned Beetle

Figure 1. Current 

infestations (blue 

dots, top map) of 

Asian longhorned 

beetle, Anoplophora 

glabripennis, in the 

United States; potential 

areas at risk of 

becoming infested (red, 

on bottom map). (Top: 

USDA Forest Service • 

AFPE Online Mapping; 

bottom: USDA APHIS)

Figure 2. Adult of Asian 

longhorned beetle. 

(Michael Bohne, 

Bugwood.org)
A Photographic Guide 367

Images of Asian

Longhorned Beetle

(continued)

Figure 3. The invasion 

of North America by 

Asian longhorned 

beetle was likely caused 

by the shipment of 

massive quantities of 

raw wooden packing 

material from Asia (top). 

To reduce risks of further 

such invasions, wooden 

packing material must 

now be fumigated 

(bottom) or heat treated 

to kill larvae or other 

stages in wood. (Both 

photos: Larry R. Barber, 

USDA Forest Service, 

Bugwood.org) 
368 Forest Pest Insects in North America:

Images of Asian

Longhorned Beetle

(continued)

Figure 5. Left, sign of oviposition (chewed pit) on the trunk; right, eggs of Asian 

longhorned beetle. (Left: Kenneth R. Law, USDA APHIS PPQ, Bugwood.org; 

right: Melody Keena, USDA Forest Service, Bugwood.org)

Figure 6. Mixed age 

(top) and mature 

(bottom) larvae of Asian 

longhorned beetle. 

(Top: Steven Katovich, 

USDA Forest Service, 

Bugwood.org; bottom: 

Kenneth R. Law, 

USDA APHIS PPQ, 

Bugwood.org)

Figure 4. Chewed bark 

on twig, caused by 

maturation feeding of 

adult Asian longhorned 

beetles. (Dean 

Morewood, Health 

Canada, Bugwood.org)
A Photographic Guide 369

Images of Asian

Longhorned Beetle

(continued)

Figure 7. Pupa of Asian longhorned borer: left, extracted; right, in a pupal 

chamber, with frass. (Left: Michael Bohne, Bugwood.org; right: Kenneth R. Law, 

USDA APHIS PPQ, Bugwood.org)

Figure 8. Larva feeding tunnels of Asian longhorned beetles in small trunk 

(top), and tunnels as seen in cross section of cut branch (bottom). (Top: Larry 

R. Barber, USDA Forest Service, Bugwood.org; bottom: E. Richard Hoebeke, 

Cornell University, Bugwood.org)
370 Forest Pest Insects in North America:

Images of Asian

Longhorned Beetle

(continued)

Figure 9. Emergence holes of Asian longhorned beetles. (E. Richard Hoebeke, 

Cornell University, Bugwood.org)

Figure 10. Dead 

branches in tops of 

trees are a sign of 

Asian longhorned beetle 

infestation. (Dennis 

Haugen, USDA Forest 

Service, Bugwood.org)
A Photographic Guide 371

Figure 11. Suvey for Asian longhorned beetle infestations are based on visual 

detection of all signs of infestation; eradication efforts includes implementing 

a regulated area (quarantine), conducting surveys of host trees, removing of 

infested trees, and using treatment applications. (Top: Thomas B. Denholm, 

New Jersey Department of Agriculture, Bugwood.org; bottom: USDA Agricultural 

Research Service Archive, USDA Agricultural Research Service, Bugwood.org)

Compared with other longhorned beetles, relatively few natural enemies 

of ALB have thus far been identified. Egg parasitoids are unknown. 

Larval parasitoids include Dastarcus longulus Sharp (Coleoptera: 

Colydiidae), Scleroderma guani Xiao et Wu (Hymenoptera: Bethylidae), 

Bullaea sp. (Diptera: Tachinidae), and Megarhyssa sp. (Hymenoptera: 

Ichneumonidae). Pupal parasitoids include D. longulus, S. guani, and 

Aprostocetus sp. (Hymenoptera: Eulophidae). Among these, D. longulus

and S. guani appeared to be the most promising for biological control 

purposes (see websites mentioned on next page for further details).

Important Biological Control 

Agents Related to this 

Pest Species
372 Forest Pest Insects in North America:

Web Links for Information 

on Asian Longhorned Beetle

http://www.eppo.org/QUARANTINE/insects/Anoplophora_glabripennis/

ANOLGL_ds.pdf; EPPO factsheet on Asian longhorned beetle as 

European quarantine pest.

http://www.umassgreeninfo.org/fact_sheets/wood_attackers/asian_

longhorned_beetle.html.

http://www.massnrc.org/pests/pestFAQsheets/asianlonghorned.html; 

Massachusetts fact sheet focusing on biology and recognition.

http://en.wikipedia.org/wiki/Asian_long-horned_beetle; Wikipedia 

article.

http://www.uvm.edu/albeetle/research/biocontrol.html#NaturalEnemies; 

discussion of natural enemies of Asian longhorn borer found in surveys 

in China.

www.beetlebusters.info; USDA Asian longhorned beetle website.

www.aphis.usda.gov; eradication program information.

Cavey, J.F., E.R. Hoebeke, S. Passoa, and S.W. Lingafelter. 1998. 

A new exotic threat to North American hardwood forests: an Asian 

longhorned beetle, Anoplophora glabripennis Motschulsky (Coleoptera: 

Cerambycidae): I. Larval description and diagnosis. Proceedings of the 

Entomological Society of Washington 100(2): 373-381. 

Haack, R.A., K.R. Law, V.C. Mastro, H.S. Ossenbruggen, and B.J. 

Raimo. 1997. New York’s battle with the Asian long-horned beetle. 

Journal of Forestry 95(12): 11-15. 

Li, W. and C. Wu. 1993. Integrated Management of Longhorn beetles 

Damaging Poplar Trees. Beijing, China. Forest Press. 290 p. 

Nowak, D.J., J.E. Pasek, R.O. Sequeira, D.E. Crane, and V.C. Mastro. 

2001. Potential effect of Anoplophora glabripennis (Coleoptera: 

Cerambycidae) on urban trees in the United States. Journal of Economic 

Entomology 94(1): 116-122. 

Hu, J.F., S. Angeli, S. Schuetz, Y.Q. Luo, and A.E. Hajek. 2009. 

Ecology and management of exotic and endemic Asian longhorned beetle 

Anoplophora glabripennis. Agricultural and Forest Entomology 11: 

359-375.

Articles
A Photographic Guide 373

100. Poplar Borer, Saperda calcarata Say (Coleoptera: Cerambycidae)

Orientation to Pest Poplar borer, Saperda calcarata Say, is a native North American 

insect found throughout Canada and the United States, attacking 

poplars (Populus) and on occasionally willows (Salix). It can become 

a significant pest of both eastern cottonwood (Populus deltoides Bartr. 

Ex Marsh) in southern regions and quaking aspen (P. tremuloides

Michx.) further north. Overwintered adults emerge from June until 

August. Females lay eggs in slits chewed into the bark, most often in 

isolated, trees growing in full sun or in trees along stand edges where 

they are more exposed to sunlight. Trees stressed by over-maturity, 

grass competition, or poor site conditions are more likely to be attacked. 

Larval development typically takes 3-4 years, but can vary from two to 

five. Signs and symptoms of this pest include swollen areas on trunks 

and larger branches, exit holes, and woodpecker excavations. Infested 

trees may have varnish-like stains on the bark below the points of attack, 

where reddish sap has oozed out. Fresh sap and coarse, fibrous frass are 

good indicators of an active larval gallery. Infestations often do not kill 

trees outright, but the trunk or branches may be weakened and break 

in wind, ice, or snow storms. Small trees may be killed by girdling 

from joining of several larval galleries. Surveys in northern states and 

Canadian provinces have found attack rates on quaking aspen by poplar 

borer to be quite high (>50 percent), especially in more open park-like 

settings where trees are open-grown. Maintaining well-stocked stands 

and avoiding poor-quality sites reduces the likelihood of infestation. 

Removal of infested trees was not shown to be helpful in reducing 

infestation levels since it resulted in lower stand density that encouraged 

further attack. It is recommended that poplar stands be well-stocked and 

clear cut at maturity. 

Poplars (Populus) are the preferred hosts of this borer. Quaking aspen 

(P. tremuloides) is favored in northern areas, cottonwood in southern 

areas. Balsam poplar (P. balsamifera L.) is another favored host where 

it occurs. Willow (Salix) has been reported as a host. 

This species is found throughout Canada and the United States where 

poplars are present. 

Hosts Commonly Attacked

Distribution

Figure 1. Adults of poplar borer, Saperda calcarata. (Left: Whitney Cranshaw, 

Colorado State University, Bugwood.org; right: James Solomon, USDA Forest 

Service, Bugwood.org)

Images of 

Poplar Borer
374 Forest Pest Insects in North America:

Images of 

Poplar Borer (continued)

Figure 2. Larvae of 

poplar borer in galleries 

and pupa in pupal 

chamber, surrounded 

by characteristic coarse 

fibrous frass (left); close 

up of poplar borer larvae 

(right). (Left: James 

Solomon, USDA Forest 

Service, Bugwood.org; 

right: Whitney 

Cranshaw, Colorado 

State University, 

Bugwood.org)

Figure 3. Sap leakage 

and bark staining on 

quaking aspen is a 

sign of poplar borer 

infestation. (Steven 

Katovich, USDA Forest 

Service, Bugwood.org)
A Photographic Guide 375

Images of 

Poplar Borer (continued)

Figure 4. Internal 

appearance of poplar 

borer damage, with 

bark cut open. (USDA 

Forest Service - Ogden 

Archive, USDA Forest 

Service, Bugwood.org)

Figure 5. Frass being expelled from larval gallery of poplar borer. (Whitney 

Cranshaw, Colorado State University, Bugwood.org)
376 Forest Pest Insects in North America:

Images of 

Poplar Borer (continued)

Figure 6. Eastern cottonwood trees (Populus deltoides ssp. deltoides Bartram ex 

Marsh.) broken due to tunneling of poplar borer. (James Solomon, USDA Forest 

Service, Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

Natural mortality of the poplar borer is frequently high and a variety 

of parasitoids have been reared from this species in various locations. 

Studies in Canada revealed that egg infertility, climate, excessive sap 

flow, and natural enemies destroyed 81 percent of the population of 

this borer. Woodpeckers can remove many late-stage larvae. However, 

while descriptive work has been done in some locations, no fundamental 

understanding exists of the importance of natural enemies as control 

agents for this borer. 

http://www.colostate.edu/Dept/CoopExt/4dmg/Pests/popborer.htm; fact 

sheet of the Colorado State University extension service.

http://wiki.bugwood.org/Archive:Borers/Saperda_calcarata; fact sheet of 

Bugwood Wiki.

Solomon, J.D. 1995. Guide to insect borers of North American broadleaf 

trees and shrubs. Agricultural Handbook 706. Washington D.C.: U.S. 

Department of Agriculture, Forest Service: 735 p. (Saperda calcarata, 

pages 334-338). 

Broberg, C.L. and J.H. Borden. 2005. Host preference by Saperda 

calcarata Say (Coleoptera: Cerambycidae). Journal of the Entomological 

Society of British Columbia 102: 27-34.

Web Links for Information 

on Poplar Borer

Articles
A Photographic Guide 377

102. Cottonwood Borer, Plectrodera scalator (Fabricius) (Coleoptera: 

Cerambycidae)

Orientation to Pest Cottonwood borer, Plectrodera scalator (Fabricius), is a native insect 

that attacks cottonwoods and poplars (Populus), willows (Salix), and 

species of Platanus, Albizia, and Helianthus. Adults first emerge in late 

spring and feed on the shoots of young trees. Mating and egg-laying 

occur throughout the summer. Females dig away soil from the base of 

the tree, where they cut a niche in the bark, and deposit one or several 

eggs. Larvae feed in the bases and roots of live trees of all sizes. At first 

larvae mine the inner bark, but by fall larvae bore into the wood. Two or 

more growing seasons are required for larval development. In their last 

year, the large larvae create tunnels at the base of the tree, where they 

pupate the falling spring. New adults emerge by chewing through the 

pupal chamber and digging their way out of the soil. Young trees may be 

hollowed out, partially severed, or girdled near the root collar, causing 

breakage. Greatest damage occurs to trees in plantations and nurseries, 

and young stands on sandy soils.

This borer attacks cottonwoods and poplars (Populus), willows (Salix), 

and species of Platanus, Albizia, and Helianthus.

The cottonwood borer is found New York to Montana and south to Texas. 

Damage is greatest in the southern United States.

Hosts Commonly Attacked

Distribution

Images of 

Cottonwood Borer

Figure 1. Adult of 

cottonwood borer, 

Plectrodera scalator. 

(Top: Charles T. Bryson, 

USDA Agricultural 

Research Service, 

Bugwood.org; bottom: 

Donald Duerr, USDA 

Forest Service, 

Bugwood.org)
378 Forest Pest Insects in North America:

Images of Cottonwood

Borer (continued)

Figure 3. Larvae of cottonwood borer in root of eastern cottonwood (Populus 

deltoides ssp. deltoides Bartram ex Marsh.) (left) and in stem of young tree 

(right). (Both photos: James Solomon, USDA Forest Service, Bugwood.org)

Figure 2. Adult female 

of cottonwood borer 

deposting an egg 

below the soil line into 

a young cottonwood 

shoot. (James Solomon, 

USDA Forest Service, 

Bugwood.org)
A Photographic Guide 379

Images of Cottonwood

Borer (continued)

Figure 4. Pupa of 

cottonwood borer in 

cottonwood shoot. 

(James Solomon, 

USDA Forest Service, 

Bugwood.org)

Figure 5. Two views of damage from cottonwood borer at base of cottonwood 

rootstocks. (Both photos: James Solomon, USDA Forest Service, Bugwood.org)
380 Forest Pest Insects in North America:

Little is known of the natural enemies of this species, except that 

cottonwood borer is sometimes parasitized by the sarcophagid fly 

Sarcophaga vericauda Hungerford, or parasitic wasps in the genera 

Ibalia, Rhyssa, or Megarhyssa. It is also susceptible to applications of the 

fungal biopesticide Beauveria bassiana.

http://www.ento.okstate.edu/ddd/insects/cottonwoodborer.htm; fact sheet 

of the Oklahoma State University.

http://www.forestpests.org/nursery/cwborers.html; fact sheet of the 

USDA Forest Service.

Solomon, J.D. 1980. Cottonwood borer (Plectrodera scalator) - a 

guide to its biologv, damage, and control. Research Paper SO157. New 

Orleans, LA, U.S. Department of Agriculture, Forest Service, Southern 

Forest Experiment Station: 10 p.

Forschler, B.T. and G.L. Nordin. 1989. Impact of Beauveria bassiana on 

the cottonwood borer Plectrodera scalator (Coleoptera: Cerambycidae), 

in a commercial cottonwood nursery. Journal of Entomological Science

24(2): 186-190. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Cottonwood Borer

Articles
A Photographic Guide 381

103. Banded Hickory Borer, Knulliana cincta (Drury) (Coleoptera: 

Cerambycidae)

Orientation to Pest Banded hickory borer, Knulliana cincta (Drury), is native to North 

America and is found in the southern United States, west to Texas, and 

in northern Mexico. Three subspecies of this beetle have been named: 

Knulliana c. cincta (Drury), found in eastern North America west to 

Texas; Knulliana cincta ochracea (Bates), found in the southeastern 

United States, northeastern Mexico, and the Bahamas; and Knulliana 

cincta sonorensis (Schaeffer), found from Texas to Arizona, and adjacent 

regions in Mexico. This borer breeds in the dead branches and trunks of 

many hardwoods. The adult is dark brown and 1.6-3.0 cm long. The body 

is covered with gray hairs, and there are short sharp spines on the corners 

of the thorax. Each wing cover has a yellow spot across it, giving the 

appearance of a band across the back. Eggs are laid in summer beneath 

the bark or directly on the wood of recently felled, dying, or dead trees. 

The larvae feed under the bark during the remainder of the summer, 

forming galleries in the wood and ejecting frass through openings in the 

bark. During the fall and following summer larvae continue to feed in 

the wood and pupate in the fall or spring between lumps of frass at the 

end of the larval gallery. The life cycle most likely requires two years for 

completion. Cordwood, logs, posts, and rustic work may be damaged by 

this species. Adults are attracted to lights.

This borer attacks hickory (Carya), pecan (Carya illinoinensis

[Wangenh.] K. Koch), walnut (Juglans), oak (Quercus), eastern 

hophornbeam (Ostrya virginiana [Mill.] K. Koch ), plum (Prunus), apple 

(Malus), chestnut (Castanea), hackberry (Celtis), pear (Pyrus), willow 

(Salix), mesquite (Prosopis), orange (Citrus), Sapindus, and Leucaena. 

Hickory appears to be preferred. 

This species is found in the United States from Virginia south to Florida 

and west to Oklahoma and Texas, and in northern Mexico.

Hosts Commonly Attacked

Distribution

Images of Banded

Hickory Borer

Figure 1. Adult banded 

hickory borer, Knulliana 

cincta. (Maury J. Heiman)
382 Forest Pest Insects in North America:

Images of Banded

Hickory Borer (continued)

Figure 2. Larva of banded hickory borer. (Lacy L. Hyche, Auburn University, 

Bugwood.org)

Figure 3. Larval galleries of banded hickory borer. (Lacy L. Hyche, Auburn 

University, Bugwood.org)

Little is known of the natural enemies of this species, except that it is 

sometimes parasitized by the ichneumonid wasp Labena grallator (Say). 

http://www.texasento.net/Knulliana.htm; a collector’s website about 

beetles from Texas.

http://www.insectsofwestvirginia.net/b/knulliana-cincta.html. 

None

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Banded Hickory Borer

Articles
A Photographic Guide 383

104. Locust Borer, Megacyllene robiniae (Forster) (Coleoptera: 

Cerambycidae)

Orientation to Pest Locust borer, Megacyllene robiniae (Forster), is native to the United 

States and bores in black locust (Robinia pseudoacacia L.) trunks. 

Attacks occur most often in young trees or in older trees stressed by 

drought or poor soil, or that have been overtopped by other trees. This 

borer formerly was limited to its native range in Pennsylvania, south in 

the Appalachian Mountains to Georgia and in the Ozark Mountains of 

Arkansas and Missouri. However, black locust has been widely planted 

outside this range and the borer is now found in those locations as well. 

Black locusts have been widely planted for restoration of strip-mined 

areas. Adults of locust borer emerge in late summer and are commonly 

seen feeding on pollen on field goldenrod (Solidago canadensis L.). 

Females lay their eggs in crevices of rough bark and around wounds of 

living trees. Larvae bore into the bark and construct overwintering cells. 

In the following spring, larval activity is resumed and sap may be seen 

oozing from the larval entry holes. Larvae bore into the wood and feed 

until they mature in mid-summer. During their feeding period, larvae 

tunnel extensively throughout the heartwood. Maturing larvae construct 

a tunnel to the exterior, through which adults later emerge. There is one 

generation per year. Attack is most common on stressed trees, such as 

those on reclaimed mining sites. Borer activity often results in wind 

breakage of trees, followed by excessive branching. Attack rates increase 

as the proportion of black locust in the stand increases, and larval to adult 

survivorship increases as the attack rate increases. 

Locust borer is a specialist that feeds only on black locust 

(R. pseudoacacia).

Locust borer is found throughout the United States wherever black locust 

grows naturally or has been introduced.

Hosts Commonly Attacked

Distribution

Images of 

Locust Borer

Figure 1. Adult locust 

borer, Megacyllene 

robiniae. (Jon Yuschock, 

Bugwood.org)
384 Forest Pest Insects in North America:

Images of Locust 

Borer (continued)

Figure 2. Locust borer 

feeding on pollen of 

goldenrod (Solidago

sp.). (David Cappaert, 

Michigan State University, 

Bugwood.org)

Figure 3. Larva of locust borer in feeding gallery. (Lacy L. Hyche, Auburn 

University, Bugwood.org)

Figure 4. Pupa of locust borer in pupation chamber. (Lacy L. Hyche, Auburn 

University, Bugwood.org)
A Photographic Guide 385

Images of Locust 

Borer (continued)

Figure 5. Cracks, frass at base of tree, and emergence holes are signs of of 

locust borer activity. (Left: James Solomon, USDA Forest Service, Bugwood.org; 

right: Whitney Cranshaw, Colorado State University, Bugwood.org)

Figure 6. Locust borer larval galleries seen in cross and lateral sections. 

(James Solomon, USDA Forest Service, Bugwood.org)

Two species of wasps, Dolichomitus irritator (Fabricius) and 

Habrolepoidea depressa (Girault), have been recorded parasitizing locust 

borer larvae at low rates (<1 percent). Natural enemies of locust borer 

have not been studied extensively.

Important Biological Control 

Agents Related to this 

Pest Species
386 Forest Pest Insects in North America:

http://www.na.fs.fed.us/spfo/pubs/fidls/locust/locust.htm; USDA Forest 

Service leaflet; extensive information on the biology, life cycle, and 

damage of the insect.

http://www.treesforyou.org/Planting/TreeCare/Healthy/Locust-B.htm; 

Washington state extension service leaflet.

http://www.dec.ny.gov/docs/lands_forests_pdf/locustb.pdf; extension 

article of the New York Department of Environmental Conservation.

http://www.ces.ncsu.edu/depts/ent/notes/O&T/trees/note18/note18.html; 

fact sheet of North Carolina State University Entomology Department; 

information on chemical control provided.

Harman, D.M., M.A. van Tyne, and W.A. Thompson. 1985. Comparison 

of locust borer Megacyllene robiniae Forster (Coleoptera: Cerambycidae) 

attacks on coal strip-mined lands and lands not mined. Annals of the 

Entomological Society of America 78: 50-53.

Harman, D.M., P. Rudolf, and K.R. Dixon. 1985. Influence of stand 

composition on locust borer (Coleoptera: Cerambycidae) attack rates. 

Journal of Entomological Science 20: 207-211.

Echaves, V.D., D.M. Harman, and A.L. Harman. 1998. Site quality in 

relation to damage by locust borer, Megacyllene robiniae Forster in black 

locust. Journal of Entomological Science 33: 106-112. 

Articles

Web Links for Information 

on Locust Borer
A Photographic Guide 387

105. White Oak Borer, Goes tigrinus (De Geer) (Coleoptera: Cerambycidae)

Orientation to Pest White oak borer, Goes tigrinus (De Geer), is native to North America 

and is found in much of the eastern United States in association with 

white (Quercus alba L.) and overcup (Q. lyrata Walter) oaks. Damage 

is greatest to younger trees and losses from this species are important 

in oak stands grown for veneer or cooperage (barrels). Reproduction is 

often concentrated in selected trees (brood trees) and removing brood 

trees can help control the pest at the stand level. Adult beetles emerge in 

May and June. Eggs are deposited in niches 6 mm in diameter that are 

cut singly into the bark. As the larvae tunnel directly into the wood, 

sap often oozes from the entrance holes in the tree and fine moist frass 

is pushed out of the tunnels to the outside. Larval galleries are about 

12 mm in diameter and 15 cm long. Pupation occurs within the gallery. 

One generation takes about 3 to 5 years. 

White oak borer breeds in white (Q. alba) and overcup (Q. lyrata) oaks. 

White oak borer is found in the eastern United States from New York to 

Florida and west to Michigan and Louisiana.

Hosts Commonly Attacked

Distribution

Images of 

White Oak Borer

Figure 1. Adult white 

oak borer, Goes tigrinus. 

(James B. Hanson, 

USDA Forest Service, 

Bugwood.org)
388 Forest Pest Insects in North America:

Images of White

Oak Borer (continued)

Figure 2. Egg of white 

oak borer, exposed 

by removal of bark 

flap. (James Solomon, 

USDA Forest Service, 

Bugwood.org)

Figure 3. Larva of white 

oak borer. (USDA Forest 

Service Fact Sheet)

Figure 4. Signs of of white oak borer activity: (left) frass pushed out of borer hole 

in tree trunk; (right) emergence holes in tree trunk. (Left: James Solomon, USDA 

Forest Service, Bugwood.org; right: USDA Forest Service Fact Sheet)
A Photographic Guide 389

Natural enemies of white oak borer have not been studied.

http://www.fs.fed.us/r8/foresthealth/pubs/oakpests/p19.html; USDA 

Forest Service factsheet covering biology and control. 

Donley, D.E. 1978. Distribution of the white oak borer Goes tigrinus

Degeer (Coleoptera: Cerambycidae) in a mixed oak stand. In: Pope, P.E. 

(ed.). Central hardwood forest Conference II. Proceedings of a meeting 

held at Purdue University at West Lafayette, Indiana, November 14-16, 

1978. West Lafayette, Indiana, USA. Department of Forestry and Natural 

Resources, Purdue University: 529-539. 

Solomon, J.D. and D.E. Donley. 1983. Bionomics and control of the 

white oak borer. Research Paper SO-198, Southern Forest Experiment 

Station, USDA Forest Service.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on White Oak Borer

Articles
390 Forest Pest Insects in North America:

106. Whitespotted Sawyer, Monochamus scutellatus (Say) (Coleoptera: 

Cerambycidae)

Orientation to Pest Whitespotted sawyer, Monochamus scutellatus (Say), is a native North 

American borer that attacks dying or recently dead conifers that have 

dried out somewhat but have not been heavily attacked by other woodfeeding insects. There are two recognized subspecies, M. scutellatus

scutellatus and M. scutellatus oregonensis. Females lay their eggs in slits 

chewed in the bark near branch scars or rough areas of bark. When eggs 

hatch, young larvae bore through the phloem into the cambium. Young 

larvae mine beneath the bark. Later instars tunnel toward the heartwood. 

Prior to pupation, the larva turns its tunnel toward the surface, where 

it pupates behind a chip plug. There is one generation per year in the 

northern part of its range and two in the southern portion. Logs left in 

the forest untended over a summer season are especially suitable for 

attack by this borer. This sawyer beetle is also able to vector the parasitic 

pinewood nematode, Bursaphelenchus xylophilus (Steiner and Buhrer) 

Nickle, which causes pine-wilt disease in Minnesota and Wisconsin. 

Damage to logs can be reduced by cutting timber in fall or winter and 

removing logs from woods before summer. Pulpwood logs can be 

partially protected by piling them in the shade or covering them with 

slash.

The whitespotted sawyer attacks a variety of conifers but prefers eastern 

white pine (Pinus strobus L.). This beetle will also attack jack pine 

(P. banksiana Lamb.), red pine (P. resinosa Ait.), balsam fir (Abies 

balsamea [L.] Mill.), white spruce (Picea glauca (Moench) Voss), black 

spruce (P. mariana (Mill.) B.S.P.), and red spruce (P. rubens Sarg.). 

Tamarack (Larix laricina (DuRoi) K. Koch) occasionally serves as a 

host.

Whitespotted sawyer is found in the United States, north of North 

Carolina and westward through the Great Lakes states, across Canada 

and north to Alaska.

Hosts Commonly Attacked

Distribution
A Photographic Guide 391

Images of 

Whitespotted Sawyer

Figure 1. Adult whitespotted sawyer, Monochamus scutellatus; right, adult 

feeding on twigs. (Left: Natasha Wright, Florida Department of Agriculture and 

Consumer Services, Bugwood.org; right: Joseph Berger, Bugwood.org)

Figure 2. Adult emergence hole (with head of adult visible) of whitespotted sawyer. 

(Laura Lazarus, North Carolina Division of Forest Resources, Bugwood.org)

Figure 3. Flagging of branches killed by adult feeding of whitespotted sawyer 

beetles. (Ronald S. Kelley, Vermont Department of Forests, Parks and 

Recreation, Bugwood.org)
392 Forest Pest Insects in North America:

Natural enemies of whitespotted sawyer include tachinids in the genus 

Eutheresia and ichneumonids in the genera Rhyssa and Dolichomitus, 

but their actual influence on population levels of whitespotted sawyer is 

unknown.

http://wiki.bugwood.org/HPIPM:Pine_Sawyers; biology of pine sawyers; 

Bugwood Wiki fact sheet.

http://www.forestpests.org/vermont/whitespottedsawyer.html; forestry 

fact sheet from Vermont.

http://www.na.fs.fed.us/spfo/pubs/fidls/ws_sawyer/ws_sawyer.htm; 

USDA Forest Service fact sheet on biology and control.

Raske, A.G. 1973. Relationship between felling date and larval density of 

Monochamus scutellatus. Bi-monthly Research Notes 29(4): 23-24.

Wingfield, M.J. and R.A. Blanchette. 1983. The pine-wood nematode, 

Bursaphelenchus xylophilus, in Minnesota and Wisconsin: insect 

associates and transmission studies. Canadian Journal of Forest 

Research 13(6): 1068-1076. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Whitespotted Sawyer

Articles
A Photographic Guide 393

107. Bagworm, Thyridopteryx ephemeraeformis (Haworth) (Lepidoptera: 

Psychidae)

Orientation to Pest Bagworm, Thyridopteryx ephemeraeformis (Haworth), is native to North 

America, and larvae defoliate arborvitae (Thuja occidentalis L.), juniper 

(Juniperus virginiana L.), eastern white pine (Pinus strobus L.), and 

blue spruce (Picea pungens Engelm.), on which they are often abundant. 

Male moths have wings but females are wingless and are unable to 

move. Males and females emerge in the fall and males fly to females. 

Females never emerge from their larval shelters (the “bag”), and mate 

while still in their bags. Females then develop their eggs, which are laid 

inside the bag and these are the overwintering stage. Eggs hatch in spring 

and some larvae spin silk threads and are blown by the wind. Upon 

alighting on plants, neonate larvae accept or reject plants, and if the 

latter spin a new thread and repeat the dispersal process. Many larvae, 

however, skip this dispersal phase and settle on their natal plants. Once 

a larva has accepted a plant, it constructs a bag and drags it around as 

it feeds. Mature larvae attach their bags to the plant and pupate inside 

them. There is one generation per year. Bagworms can be locally dense 

on ornamental plantings, causing defoliation and killing trees or shrubs. 

Damage to forest stands is not usually important, because larvae prefer 

sunny sites. Some damage does, however, occur in Atlantic white cedar 

(Chamaecyparis thyoides [L.] Britton, Sterns and Poggenb.) and black 

locust (Robinia pseudoacacia L.) stands, especially in the southern 

United States. 

Bagworm commonly attack arborvitae (T. occidentalis), juniper (J. 

virginiana), eastern white pine (P. strobes), blue spruce (P. pungens), 

Atlantic white cedar (C. thyoides), and black locust (R. pseudoacacia). 

On other hosts, bagworm larvae are rare.

Bagworm is widely distributed in the eastern United States.

Hosts Commonly Attacked

Distribution

Images of Bagworm Figure 1. Adult 

male bagworm 

moth, Thyridopteryx 

ephemeraeformis. 

(Pennsylvania 

Department of 

Conservation and 

Natural Resources 

- Forestry Archive, 

Bugwood.org)
394 Forest Pest Insects in North America:

Images of Bagworm

(continued)

Figure 2. Bagworm 

eggs dissected out of 

female inside case. 

(Lacy L. Hyche, Auburn 

University, Bugwood.org)

Figure 3. Young 

bagworm in small 

case (top); older 

bagworm with larger, 

but still mobile, case 

(bottom). (Top: Rayanne 

Lehman, Pennsylvania 

Department of 

Agriculture, 

Bugwood.org; bottom: 

Connecticut Agricultural 

Experiment Station 

Archive, Connecticut 

Agricultural Experiment 

Station, Bugwood.org)
A Photographic Guide 395

Images of Bagworm

(continued)

Figure 4. Bagworm 

caterpillar partialy 

extended outside of 

protective bag (top), 

and caterpillar pulled 

out of bag (bottom). 

(Both photos: 

Gerald J. Lenhard, 

Louiana State University, 

Bugwood.org)

Figure 5. Bagworm prepupa (bottom) and pupa (top) in bags cut open for 

viewing. (Gerald J. Lenhard, Louiana State University, Bugwood.org)
396 Forest Pest Insects in North America:

Images of Bagworm

(continued)

Figure 6. Male bagworm mating with flightless female inside her larval bag. 

(Jerry A. Payne, USDA Agricultural Research Service, Bugwood.org)

Figure 7. Bag of mature bagworm, fixed in place (left); many bagworm cases 

(right) on heavily infested plant. (Left: John H. Ghent, USDA Forest Service, 

Bugwood.org; right: Pennsylvania Department of Conservation and Natural 

Resources - Forestry Archive, Bugwood.org)
A Photographic Guide 397

Images of Bagworm

(continued)

Figure 8. High densities 

of bagworm bags 

on partly defoliated 

conifer. (Pennsylvania 

Department of 

Conservation and 

Natural Resources 

- Forestry Archive, 

Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

Natural enemies of bagworms have been frequently studied because 

the bags are large and stationary, inviting their examination. The 

ichneumonid Itoplectis conquisitor (Say), a generalist pupal parasitoid, 

is commonly found attacking bagworms and is often the most abundant 

species reared from this host. Many other species of parasitoids have also 

been reared from bagworms.

http://ento.psu.edu/extension/factsheets/bagworm; fact sheet of 

Pennsylvania State University.

http://www.uark.edu/ua/arthmuse/bagworm.html; University of Arkansas 

fact sheet.

http://njaes.rutgers.edu/pubs/publication.asp?pid=FS1144; fact sheet of 

New Jersey Rutgers NJAES Cooperative Extension.

Horn, D.J. and R.F. Sheppard. 1979. Sex ratio, pupal parasitism, and 

predation in two declining populations of the bagworm, Thyridopteryx 

ephemeraeformis (Haworth) (Lepidoptera: Psychidae). Ecological 

Entomology 4: 259-265.

Moore, R.G. and L.M. Hanks. 2004. Aerial dispersal and host plant 

selection by neonate Thyridopteryx ephemeraeformis (Lepidoptera: 

Psychidae). Ecological Entomology 29: 327-335. 

Web Links for Information 

on Bagworm

Articles
398 Forest Pest Insects in North America:

108. Birch Casebearer, Coleophora serratella (L.) (Lepidoptera: 

Coleophoridae)

Orientation to Pest Birch casebearer, Coleophora serratella (L.), is a European moth that is 

invasive in North America and is associated with birches (Betula), alders 

(Alnus), and elms (Ulmus). High densities sometimes defoliate birches, 

and this insect is considered one of the most important pests of birch in 

some parts of Canada such as Newfoundland. Because of misapplication 

of names, literature records from 1938 to 1972 under this name very 

likely do not refer to the true C. serratella as described here. The adult 

appears in late spring. Eggs are laid on host leaves and the larva feeds 

by inserting its head into small mines that it creates. The larva constructs 

a protective case, which it drags with it as it moves around to feed. 

Pupation occurs in early summer, and occurs in the larval case, which is 

fixed to the upper surface of a leaf in a sunny situation. 

Birch casebearer feeds on birches (Betula), alders (Alnus), and elms 

(Ulmus). 

Birch casebearer is found in the northeastern United States, eastern 

Canada from Newfoundland through southern Ontario into Manitoba, 

and in western Canada, in British Columbia. 

Hosts Commonly Attacked

Distribution

Images of 

Birch Casebearer

Figure 1. Adult birch 

casebearer, Coleophora 

serratella. (Ian Kimber)

Figure 2. Several 

larvae (in cases) of 

birch casebearer on 

young white birch 

leaf. (Thérèse Arcand 

- Natural Resources 

Canada, Canadian 

Forest Service)
A Photographic Guide 399

Images of Birch

Casebearer (continued)

Figure 3. Larva of birch 

casebearer, with the 

case removed. (Thérèse 

Arcand - Natural 

Resources Canada, 

Canadian Forest 

Service)

Figure 4. White birch 

defoliated by birch 

casebearer. (Claude 

Monnier - Natural 

Resources Canada, 

Canadian Forest 

Service)

Natural enemies of birch casebearer have been studied in Quebec and 

Newfoundland, and as many as 38 species of parasitoids attack this 

invasive species there. In the native range (central Europe) 25 species 

are reported associated with this case bearer. Some of these species 

(e.g., Campoplex borealis [Zett.] and Apanteles coleophorae [Wilk.], 

Apanteles mesoxanthus Ruschka, and Apanteles cornvinus Reinh.) 

have been released in North America, but there are no records of their 

establishment. 

http://www.exoticpests.gc.ca/ins_details_eng.asp?pestType=ins&lang=en

&geID=8229; Canadian factsheet on forest invasive alien species. 

Pschorn-Walcher, H. 1980. Population fluctuations and parasitisation 

of the birch-alder casebearer (Coleophora serratella L.) in relation to 

habitat diversity. Zeitschrift für Angewandte Entomologie 89(1): 63-81. 

(In German).

Guevremont, H. and J. Juillet. 1975. Parasites of the birch casebearer, 

Coleophora fuscedinella [= Coleophora serratella] Zeller (Lepidoptera: 

Coleophoridae), in the Sherbrooke region, Quebec. Phytoprotection

56 (1): 1-17. (In French).

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Birch Casebearer

Articles
400 Forest Pest Insects in North America:

109. Larch Casebearer, Coleophora laricella (Hübner) (Lepidoptera: 

Coleophoridae)

Orientation to Pest The larch casebearer, Coleophora laricella [Hübner]), is an invasive 

species from Europe that caused extensive defoliation of North American 

larch before it was brought under biological control. It has one generation 

per year. Adults emerge in late spring and deposit their eggs singly on 

needles in early summer. Newly hatched larva bore into needles and feed 

as needle miners. After larvae consume a portion of their first needle, 

a section of a mined-out needle is lined with silk, cut free, and carried 

as a case. Larvae in cases then move to other needles and continue to 

feed. Fed-on needles are only partly consumed. They remain attached 

to branches but turn brown, making damage readily visible. Cases are 

enlarged as larvae grow. Larvae overwinter in cases fixed to branches 

and resume feeding in spring on new foliage. Upon reaching maturity, 

larvae pupate in their cases from which moths later emerge. 

In North America, this moth attacks both eastern (Larix laricina [Du Roi] 

K. Koch) and western (Larix occidentalis Nuttl.) larch.

Larch casebearer occurs in Canada from the Maritmes to western Canada 

and in the United States from New England to Minnesota and, separately, 

in Washington, Oregon, Idaho and western Montana. This distribution 

corresponds to that of eastern and western larch.

Hosts Commonly Attacked

Distribution

Images of 

Larch Casebearer

Figure 1. Adults of larch casebearer (Coleophora laricella) mating. (Roger Ryan, 

USFS PNW Station, Bugwood.org)

Figure 2. Young larva of larch casebearer in needle-mining phase. (Roger Ryan, 

USFS PNW Station, Bugwood.org)
A Photographic Guide 401

Images of Larch

Casebearer (continued)

Figure 3. Older larva of larch casebearer with case. (Roger Ryan, USFS PNW 

Station, Bugwood.org)

Figure 4. View of larch 

casebearer larva with 

case partially removed. 

(Victor Ryabincov, 

Bugwood.org)

Figure 5. Close view 

of damage to needles 

caused by larch 

casebearer larval 

feeding. (Ferenc 

Lakatos, University 

of West-Hungary, 

Bugwood.org)
402 Forest Pest Insects in North America:

Images of Larch

Casebearer (continued)

Figure 7. Larch stand showing reddish-brown foliage due to feeding of larch 

casebearer. (William M. Ciesla, Forest Health Management International, 

Bugwood.org)

Figure 6. Branch 

showing yellow foliage 

that has been partly 

consumed by larch 

casebearer. (Roger 

Ryan, USFS PNW 

Station, Bugwood.org)

Figure 8. Cluster of overwintering larch casebearer in cases at tip of twig. 

(Roger Ryan, USFS PNW Station, Bugwood.org)
A Photographic Guide 403

Images of Larch

Casebearer (continued)

Figure 9. The braconid Agathis pumila (Ratzburg), one of two key species giving 

successful biological control of larch casebearer in North America. (Roger Ryan, 

USFS PNW Station, Bugwood.org)

Figure 10. The eulophid Chrysocharis laricinellae Ratzburg, showing egg-laying 

behavior. (Roger Ryan, USFS PNW Station, Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

While a larger number of parasitoids were introduced, two species—the 

braconid Agathis pumila (Ratzburg) and the eulophid Chrysocharis 

laricinellae Ratzburg—were responsible for effective biological control 

of larch casebearer in North America.
404 Forest Pest Insects in North America:

http://www.na.fs.fed.us/spfo/pubs/fidls/larch/larch.htm; USDA Forest 

Service Leaflet with information on biology, life history, damage, and 

control.

http://www.fs.fed.us/r1-r4/spf/fhp/mgt_guide/larch_casebearer/larch_

casebearer.pdf; USDA Forest Service bulletin.

http://www.fs.fed.us/r1-r4/spf/fhp/field_guide/124lrchcb.htm.

http://www.dec.ny.gov/docs/lands_forests_pdf/cbearer.pdf.

http://www.oregon.gov/ODF/privateforests/docs/fh/larchcasebearer.

pdf?ga=t.

Jagsch, A.1973. Population dynamics and parasite complex of the 

larch miner, Coleophora laricella Hb., in the natural distribution area 

of European larch, Larix decidua Mill. Zeitschrift für Angewandte 

Entomologie 73: 1-42.

Niwa, G.G. 1983. Environmental factors influencing the effectiveness 

of Agathis pumila Ratz. (Hymenoptera: Braconidae), an introduced 

parasite of the larch casebearer, Coleophora laricella Hbn. (Lepidoptera: 

Coleophoridae). Forestry Abstracts 44(11): 718.

Niwa, C.C., R.W. Stark, D.G. Burnell, and D.M.J. Knox. 1986. 

Annotated bibliography of larch casebearer (Coleophora laricella) 

parasitoids. Bulletin No. 41. Forest, Wildlife and Range Experiment 

Station, University of Idaho: 135 p.

Ryan, R.B. 1990. Evaluation of biological control: introduced 

parasites of larch casebearer (Lepidoptera: Coleophoridae) in Oregon. 

Environmental Entomology 19: 1873-1881.

Ryan, R.B. 1997. Before and after evaluation of biological control of the 

larch casebearer (Lepidoptera: Coleophoridae) in the Blue Mountains 

of Oregon and Washington, 1972-1995. Environmental Entomology 26: 

703-715. 

Web Links for Information 

on Larch Casebearer

Articles
A Photographic Guide 405

110. Pecan Cigar Casebearer, Coleophora laticornella (Clemens) 

(Lepidoptera: Coleophoridae)

Orientation to Pest The pecan cigar casebearer, Coleophora laticornella (Clemens), is a 

case-bearing moth native to North America. Its hosts include pecan 

(Carya illinoinensis [Wangenh] K. Koch), walnut (Juglans), and several 

species of hickory (Carya). It often causes serious damage to these trees. 

This insect overwinters as a partially grown larva in a case about 6 mm 

long that is attached to a limb or twig. In the spring, the larvae resume 

feeding on the newly opened buds and young foliage and when mature, 

larvae pupate within their cases. Moths emerge and lay eggs on leaves. 

Young larvae feed as leafminers, but later construct cases in which they 

remain as they move about, feeding on leaves and, the following year, 

buds. After leaf drop, larvae move back onto twigs or limbs, where they 

attach their cases for overwintering. There may be several generations 

per year. The pecan cigar casebearer occurs from New England south to 

Florida and as far west as Texas. 

Hosts of pecan cigar casebearer include pecan (Carya illinoinensis

[Wangenh] K. Koch), walnut (Juglans), and several species of hickory 

(Carya).

This moth is found in the eastern United States, from New England south 

to Florida and west to Texas. 

Hosts Commonly Attacked

Distribution

Images of Pecan

Cigar Casebearer

Figure 1. Adult pecan 

cigar casebearer, 

Coleophora laticornella. 

(Mark Dreiling)
406 Forest Pest Insects in North America:

Images of Pecan

Cigar Casebearer

(continued)

Figure 2. Larva of pecan cigar casebearer in case. (H.C. Ellis, University of 

Georgia, Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

None

None

None

Web Links for Information 

on Pecan Cigar Casebearer

Articles
A Photographic Guide 407

111. Oak Skeletonizer, Bucculatrix ainsliella Murtfeldt (Lepidoptera: 

Bucculatricidae)

Orientation to Pest The oak skeletonizer, Bucculatrix ainsliella Murtfeldt, is a native 

North American moth whose larvae skeletonize the leaves of some 

oaks (Quercus). Eggs are laid on the upper side of leaves, adjacent to 

a major vein. The first instar larvae are leafminers, forming a strongly 

contorted serpentine mine about 1 cm long. Older larvae feed externally 

on the lower leaf surfaces, causing “windows” in leaves or skeletonizing 

them. There are two generations per year. Adults are active in April and 

May (generation one) and again in July and August (generation two). 

In the southern United States fly into September. The oak skeletonizer 

overwinters as a pupa in a white cocoon about 3 mm in length. 

Occasionally outbreaks occur over large areas.

Oak skeletonizer feeds on red (Quercus rubra L.) and black (Q. velutina

Lam.) oaks. Records on chestnut oak (Q. montana Willdenow) and 

chestnut (Castanea) are unconfirmed.

The moth occurs in southern Canada and in the United States from Maine 

to North Carolina and west to Mississippi. It has also been introduced 

into British Columbia and, since 2006, into western Europe. 

Hosts Commonly Attacked

Distribution

Images of 

Oak Skeletonizer

Figure 1. Mine of first instar larva of oak skeletonizer, Bucculatrix ainsliella. (Erik 

J. van Nieukerken, Netherlands Centre for Biodiversity Naturalis, Bugwood.org)
408 Forest Pest Insects in North America:

Images of 

Oak Skeletonizer

(continued)

Figure 2. Oak skeletonizer larva feeding on the underside of an oak leaf. 

(G. Keith Douce, University of Georgia, Bugwood.org)

Figure 3. Oak skeletonizer cocoons attached to leaf veins; see also larvae 

and leaf damage (brown areas). (James Solomon, USDA Forest Service, 

Bugwood.org)
A Photographic Guide 409

Images of 

Oak Skeletonizer

(continued)

Figure 4. Leaf damage 

from larval feeding of 

oak skeletonizer. 

(James Solomon, 

USDA Forest Service, 

Bugwood.org)

Figure 5. Damage to 

an oak tree due to 

larval feeding of oak 

skeletonizer. 

(Terry S. Price, Georgia 

Forestry Commission, 

Bugwood.org)
410 Forest Pest Insects in North America:

Images of 

Oak Skeletonizer

(continued)

Figure 6. Damage to a stand of oak trees due to the oak skeletonizer. 

(Richard Jernigan, Georgia Forestry Commission, Bugwood.org)

Pupal parasitism (either by Ichneumonidae or Chalcidoidea) reached 

high levels (>40 percent parasitism) during the first generation of a 

population outbreak in British Colombia (see Gelok et al. 1998), but 

larval parasitism was very low. 

http://www.oakwilt.com/skeletonizer/index.html; website of Texas 

private nursery company.

http://www.forestpests.org/vermont/oakskeletonizer.html; fact sheet from 

Vermont Department of Forests, Parks and Recreation on lifecycle and 

management.

http://www.fs.fed.us/r8/foresthealth/pubs/oakpests/p13.html; USDA 

Forest Service fact sheet on biology and control.

http://www.microlepidoptera.nl/nieuws/art_2011.7.11.php; 

Microlepidoptera of the Netherlands: first report on its introduction into 

Europe.

Gelok, E., R. McGregor, D. Henderson, and L. Poirier. 1998. Seasonal 

occurrence and parasitism of Bucculatrix ainsliella (Lepidoptera: 

Lyonetiidae) on Quercus rubra in Burnaby, British Columbia. Journal of 

the Entomological Society of British Columbia 95: 111-116. 

Gibbons, C.F. and J.W. Butcher. 1961. The oak skeletonizer, Bucculatrix 

ainsliella, in a Michigan woodlot. Journal of Economic Entomology 54: 

681-684.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Oak Skeletonizer

Articles
A Photographic Guide 411

112. Palm Leaf Skeletonizer, Homaledra sabalella (Chambers) (Lepidoptera: 

Coleophoridae)

The palm leaf skeletonizer, Homaledra sabalella (Chambers), is a native 

moth that is an important pest of many species of palms in the southern 

United States. It is an important pest in Florida, where it sometimes 

causes serious damage to palm trees. An outbreak of what appeared to 

be this species occurred on coconut palms (Cocos nucifera L.) in Florida 

starting in about 1995 but curiously did not affect cabbage palmetto. 

While identical in appearance to the cabbage palmetto-feeding moth, the 

coconut palm-feeding population is perhaps an invasive cryptic species. 

The matter is under investigation. The following notes on life history are 

for the traditional species (the population found on cabbage palmetto). 

Female moths lay batches of, on average, 36 eggs glued to the surface of 

older palm leaves and covered with brown, papery material. The larvae 

mine in groups on both the upper and lower surfaces of older leaves, 

under webs of silk. Excrement from the larvae is deposited on top of 

the silk. Pupation takes place in the larval mines. There may be up to 

five generations per year, and there is no diapause. Cutting and burning 

infested leaves is an effective method of control.

Palm leaf skeletonizer feeds on several species of palms, including 

Canary Island date palm (Phoenix canariensis [Chabaud]) and cabbage 

palmetto (Sabal palmetto [Walter] Schultes and Schultes), the latter 

being an important native species in Florida. In Puerto Rico, the principal 

palm attacked is the Puerto Rico hat palm, Sabal causiarum (O.F. Cook) 

Becarri. This species also feeds on Latan palms (Latania spp.) and to a 

lesser extent on Washingtonia robusta H.Wendl.

This insect is found across the southern United States from Florida to 

California, this being the northern extension of its range, which lies 

principally in Cuba, Puerto Rico, and Hispaniola.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of Palm Leaf

Skeletonizer

Figure 1. Adult palm leaf 

skeletonizer, Homaledra 

sabalella. (Bo Zaremba)
412 Forest Pest Insects in North America:

Images of Palm Leaf

Skeletonizer (continued)

Figure 2. Damage from feeding of larvae of the palm leaf skeletonizer. 

(Tim Borschat, Bugwood.org)

An undescribed tachinid fly in the genus Phytomyptera was observed 

in Florida associated with the decline of serious outbreaks of this insect 

in the 1990s. In older records from Florida, larvae of the carabid beetle 

Plochionus amandus Newman and ants are listed as predators of this 

species. Also, listed are six species of hymenopterous parasitoids. 

http://fshs.org/Proceedings/Password%20Protected/

2007%20vol.%20120/FSHS%20vol.%20120/356-359.pdf; an in-depth 

article on this species. 

Creighton, J.T. 1937. Homaledra sabalella Chambers, the major pest of 

palms in Florida. Journal of Economic Entomology 30: 590-595. 

Howard, F.W. and E. Abreu. 2007. The palm leaf skeletonizer, 

Homaledra sabalella (Lepidoptera: Coleophoridae): status and potential 

pest management options. Proceedings of the Florida Horticultural 

Society 120: 356-359. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Palm Leaf Skeletonizer

Articles
A Photographic Guide 413

113. Mimosa Webworm, Homadaula anisocentra Meyrick (Lepidoptera: 

Galacticidae)

Orientation to Pest Mimosa webworm, Homadaula anisocentra Meyrick, is an invasive 

moth from China that was first recorded in North America in 

Washington, D.C., in 1940. Larvae feed on flowers and foliage of the 

introduced Asian silktree (mimosa) (Albizia julibrissin Durazz.) and the 

native North American honeylocust (Gleditsia triacanthos L.). Larvae 

web together areas on which they are feeding. This insect over-winters 

as pupae encased in cocoons on bark of their host tree or in the leaf 

litter below. Eggs of first generation moths are laid on leaves and hatch 

in early to mid-June. There are two generations each year and second 

generation moths emerge in August. 

The caterpillars of this moth feed on the introduced Asian silktree (A. 

julibrissin) and the native North American honeylocust (G. triacanthos).

This insect occurs from Massachusetts and Pennsylvania, south to 

Florida and west to Mississippi, Kansas and Nebraska. 

Hosts Commonly Attacked

Distribution

Images of 

Mimosa Webworm

Figure 1. Adult of 

mimosa webworm, 

Homadaula anisocentra. 

(Ashley Bradford, 

Northern Virginia, 

Wikipedia Commons)

Figure 2. Larva of mimosa webworm. 

(Stan Gilliam) 
414 Forest Pest Insects in North America:

Images of Mimosa

Webworm (continued)

Figure 3. A cocoon of 

mimosa webworm, the 

overwintering stage, in 

a bark crack. (Michael 

Masiuk, Bugwood.org)

Figure 4.Web produced by larvae of the mimosa webworm. (Brian Kunkel, 

University of Delaware, Bugwood.org)
A Photographic Guide 415

Images of Mimosa

Webworm (continued)

Figure 5. Host tree 

heavily damaged by 

mimosa webworm. 

(Michael Masiuk, 

Bugwood.org)

Some North American parasitoids attack this species, but parasitism rates 

are very low (2-4 percent). However, at least in Iowa one parasitoid, the 

eulophid Elasmus albizziae, attacked 39-47 percent of the pupae. 

http://woodypests.cas.psu.edu/factsheets/insectfactsheets/html/Mimosa_

Webworm.html; factsheet of Pennsylvania State University.

Heppner, J.B. and G.W. Dekle. 1975. Mimosa webworm, Homadaula 

anisocentra Meyrick (Lepidoptera: Plutellidae). Entomology Circular 

No. 157, Division of Plant Industry, Florida Department of Agriculture 

and Consumer Services.

Bastian, R.A. and E.R. Hart. 1989. First-generation parasitism of the 

mimosa webworm (Lepidoptera: Plutellidae) by Elasmus albizziae

(Hymenoptera: Eulophidae) in an urban forest. Environmental 

Entomology 19: 409-414.

Sadof, C.S. and R.T. Snyder. 2005. Seasonal abundance of Homadaula 

anisocentra (Lepidoptera: Plutellidae) and two parasitoids, Elasmus 

albizziae (Hymenoptera: Elasmidae) and Parania geniculata

(Hymenoptera: Ichneumonidae), in an urban forest. Environmental 

Entomology 34: 70-74. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Mimosa Webworm

Articles
416 Forest Pest Insects in North America:

114. Lodgepole Needleminer, Coleotechnites milleri (Busck) (Lepidoptera: 

Gelechiidae)

Orientation to Pest Lodgepole needleminer, Coleotechnites milleri (Busck), is a native North 

American gelechiid moth whose larvae mine needles of lodgepole pine 

(Pinus contorta Douglas ex Loud.). Larvae of all ages mine needles. 

Sustained and repeated outbreaks of this species have occurred in 

Yosemite National Park in California, causing widespread tree mortality. 

The adults are active from mid-July to mid-August in odd numbered 

years (each generation requires two years). Eggs are laid in late summer 

and hatch the same year. First instars mine a single needle, near the 

growing tip, and overwinter inside the mined needle. The following year, 

larvae feed on several needles (as needle miners) and develop to the 

fourth instar by the end of their second growing season. Fourth instars 

overwinter in mined needles and in the third year, fifth instars complete 

their feeding in spring, pupate in mined needles, and emerge as adults by 

mid-summer. 

The only known host is lodgepole pine (P. contorta).

This insect is found in western North American (United States and 

Canada) within the range of lodgepole pine.

Hosts Commonly Attacked

Distribution

Images of 

Lodgepole Needleminer

Figure 1. Adult of 

lodgepole needleminer, 

Coleotechnites milleri. 

(Kipling Will)

Figure 2. Larva of 

lodgepole needleminer. 

(Scott Tunnock, 

USDA Forest Service, 

Bugwood.org)
A Photographic Guide 417

Images of Lodgepole

Needleminer (continued)

Figure 3. Damage from lodgepole needleminer. (USDA Forest Service - Ogden 

Archive, USDA Forest Service, Bugwood.org)

Figure 4. Stand of lodgepole pine damaged by lodgepole needleminer. 

(Louisiana State University Archive, Louisiana State University, Bugwood.org)

Many parasitoids and other natural enemies attacked this species 

during the declining phase of an outbreak in California (Struble, 1967). 

Collectively the larval and pupal parasitoids caused 28-46 percent 

mortality. 

None

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Lodgepole Needleminer
418 Forest Pest Insects in North America:

Articles on

Lodgepole Needleminer

Struble, G.R. 1967. Insect enemies in the natural control of the lodgepole 

needle miner. Journal of Economic Entomology 60: 225-228.

Struble, G.R. 1973. Biology, ecology, and control of the lodgepole needle 

miner. Technical Bulletin, U.S. Department of Agriculture No. 1458: 

38 p. 
A Photographic Guide 419

115. Banded Ash Clearwing, Podosesia aureocincta Purrington 

and Nielson, and Ash/Lilac Clearwing, Podosesia syringae (Harris) 

(Lepidoptera: Sesiidae)

Orientation to Pest Banded ash clearwing, Podosesia aureocincta Purrington and Nielson, 

and the ash/lilac borer Podosesia syringae (Harris), are similar native 

North American clearwing moths with overlapping host ranges. 

Podosesia syringae attacks lilac (Syringa), ash (Fraxinus), privet 

(Ligustrum) and other trees and shrubs. Podosesia aureocincta breeds 

solely in ash, principally green ash (Fraxinus pennsylvanica Marshall) 

and white ash (F. americana L.). Before 1975, P. aureocincta was 

thought to be a subspecies or just a late brood of the ash/lilac borer 

emerging from September to December. Adults of P. aureocincta can be 

recognized and separated from P. syringae by the presence of a narrow 

orange-yellow partial band on the fourth abdominal segment. The larvae 

of P. aureocincta can be distinguished from those of P. syringae because 

P. aureocincta larvae have fewer crochets on their abdominal prolegs 

(12 to 16 per row vs. 16 to 20 per row for P. syringae). The life histories 

of these two species are similar. In both, females lay eggs in cracks on 

the bark of ash (or for P. syringae, various hosts). Larvae tunnel through 

the wood but continue to expel sawdust and frass, which accumulates 

around the gallery opening from which the moth will eventually emerge. 

The overwintering stage in both species is the partly grown larva, which 

becomes active in spring. Pupation occurs at the end of the larval gallery. 

Adults of banded ash clearwing emerge later in the year (SeptemberDecember) than those of P. syringae. There is only one generation of 

P. syringae per year. Both species cause damage in forest trees and 

landscape or nursery trees. The damage caused to ash by either species, 

however, is negligible compared to that from the invasive emerald 

ash borer, Agrilus planipennis Fairmaire. However, P. aureocincta is 

regarded as an important timber pest in the southern United States, and 

in the prairie states both species are damaging to trees in shelterbelts. 

Podosesia syringae attacks lilac (Syringa), ash (Fraxinus), privet 

(Ligustrum), and other trees and shrubs, while P. aureocincta breeds 

principally in green (F. pennsylvanica) and white (F. americana) ash.

Podosesia syringae occurs more widely than P. aureocincta, being found 

from Texas to Saskatchewan and east throughout the United States 

and Canada. Banded ash clearwing, P. aureocincta, is known just from 

the United States, from New York to Florida and west to Oklahoma. 

Populations of P. aureocincta are also more scattered than are those 

of P. syringae.

Hosts Commonly Attacked

Distribution
420 Forest Pest Insects in North America:

Images of 

Ash/Lilac Clearwing

Figure 1. Adult of the 

ash/lilac clearwing, 

Podosesia syringae; 

the adult of the closely 

related species, the 

banded ash clearwing, 

Podosesia aureocincta

(not shown) is very 

similar but has a 

distinctive narrow yellow 

band around the middle 

of the abdomen. 

(James Solomon, 

USDA Forest Service, 

Bugwood.org)

Figure 2. Larva of ash/lilac borer, Podosesia syringae, in green ash twig. 

(James Solomon, USDA Forest Service, Bugwood.org)

Figure 3. Death of twigs killed by larvae of ash/lilac borer; note frass in photo on 

right. (Both photos: James Solomon, USDA Forest Service, Bugwood.org)
A Photographic Guide 421

Images of Ash/Lilac 

Clearwing (continued)

Figure 4. Pupal skins of ash/lilac borer left behind on ash trunk following moth 

emergence. (Both photos: Whitney Cranshaw, Colorado State University, 

Bugwood.org)

Figure 5. Larval galleries of the ash/lilac borer seen in cross section, in finished 

ash lumber. (James Solomon, USDA Forest Service, Bugwood.org)

Natural enemies of these clearwings have received little attention. 

Woodpeckers feed extensively on the immature stages. Several 

parasitoids have also been reared from them, but their importance has 

not been assessed. The ichneumonid Phaeogenes ater Cresson and 

the braconid Macrocentrus marginator (Nees) were reared from P. 

aureocincta, while the ichneumonid Lissonota sp. was reared from both 

P. aureocincta and P. syringae. Nematode applications can reduce borer 

damage in nurseries.

Important Biological Control 

Agents Related to this 

Pest Species
422 Forest Pest Insects in North America:

Web Links for Information 

on Ash/Lilac Borer 

and Banded Ash Clearwing

http://ipm.illinois.edu/landturf/insects/ash_lilac_borer/index.html; fact 

sheet from the University of Illinois covering both species.

http://images.bugwood.org/mediawiki/pdf.cfm?title=Archive:Ash/

Podosesia_aureocincta; Bugwood fact sheet.

http://independent.academia.edu/VernonAntoineBrouJr/Papers/298747/

The_Flight_Periods_of_Podosesia_Syringae_Harris_Ana_Podosesia_

Aureocincta_Purrington_and_Nielsen_In_Louisiana; comparative data 

on flights of P. aureocincta and P. syringae.

McKnight, M.E. and S. Tunnock. 1973. The borer problem in green ash 

in North Dakota shelterbelts. North Dakota Farm Research 30(5): 8-14.

Purrington, F.F. and D.G. Nielsen. 1979. Genitalic difference between 

males of Podosesia aureocincta and P. syringae (Lepidoptera: Sesiidae). 

Annals of the Entomological Society of America 72: 552-555.

Solomon, J.D. 1983. Lilac borer (Podosesia syringae) discovered 

causing terminal mortality and resulting forks in young green ash trees. 

Journal of the Georgia Entomological Society 18: 320-323.

Purrington, F.F. and D.G. Nielsen. 1987. New host records of parasitic 

Hymenoptera in clearwing moths (Lepidoptera: Sesiidae). Great Lakes 

Entomologist 20: 141-142.

Gill, S., J. Davidson, W. MacLachlan, and W. Potts. 1994. Controlling 

banded ash clearwing moth borer using entomopathogenic nematodes. 

Journal of Arboriculture 20: 146-149.

Articles
A Photographic Guide 423

116. Red Oak Clearwing Borer, Paranthrene simulans (Grote) (Lepidoptera: 

Sesiidae)

Orientation to Pest Red oak clearwing borer, Paranthrene simulans (Grote), is a native North 

American clearwing moth that affects American chestnut (Castanea 

dentata [Marsh.] Borkh.) and some oaks. It is widespread in both eastern 

Canada and the eastern United States. Adult moths emerge from April to 

June in the southern parts of the species’ range and June and July in the 

northern portion. Females lay eggs in bark crevices on the lower trunk. 

Larvae burrow in the inner bark and create ovoid chambers. As larvae 

grow, they extend their galleries. Larvae overwinter for two winters in 

their galleries. In spring, after the second winter, larvae bore to the bark 

surface, cap the gallery exits with a thin membrane, and then pupate. The 

whole life cycle requires two years. Open-grown trees are attacked most 

often. Bark swelling, pellet-like frass in bark cracks, and empty pupal 

cases on the trunk are visible signs of attack by this borer. Tunneling 

causes losses to nursery tree production and promotes decay in the lower 

butt, below the cut made for harvest. Pheromone traps are available to 

monitor moth flight to time pesticide applications. 

This borer attacks American chestnut (C. dentata) and species in both the 

red and white oak groups. Moth preference among hosts varies by region. 

In the southern United States older Nuttall (Quercus texana Buckl.), 

cherrybark (Q. pagoda Rafinesque), Shumard (Q. shumardii Buckland), 

and eastern black (Q. velutina Lamb.) oaks are the principal hosts. In the 

northeastern United States, injury is greatest in nursery stock and sapling 

red or white oak group trees. 

This borer occurs in the eastern parts of Canada and the United States, 

north to Minnesota and south and west to Texas. 

Hosts Commonly Attacked

Distribution

Images of Red Oak

Clearwing Borer

Figure 1. Adult red 

oak clearwing borers, 

Paranthrene simulans. 

(Top: Daniel Herms, The 

Ohio State University, 

Bugwood.org; bottom: 

James Solomon, 

USDA Forest Service, 

Bugwood.org)
424 Forest Pest Insects in North America:

Images of Red Oak

Clearwing Borer

(continued)

Figure 3. Emergence holes of red oak clearwing borer on lower trunk of Nuttall 

oak. (James Solomon, USDA Forest Service, Bugwood.org)

Figure 2. Larva of red oak clearwing 

borer in its gallery. (USDA Forest 

Service Fact Sheet)

Important Biological Control 

Agents Related to this 

Pest Species

No information is available on the natural enemies of this species.

http://www.fs.fed.us/r8/foresthealth/pubs/oakpests/p17.html; USDA 

Forest Service fact sheet.

http://images.bugwood.org/mediawiki/pdf.cfm?title=Archive:Oak/

Paranthrene_simulans; Bugwood Wiki fact sheet.

McKern, J.A. and A.L. Szalanski. 2007. Molecular diagnostics of 

economically important clearwing moths (Lepidoptera: Sesiidae). 

Florida Entomologist 90: 475-479.

Web Links for Information on

Red Oak Clearwing Borer 

Articles
A Photographic Guide 425

117. Persimmon Borer, Sannina uroceriformis Walker (Lepidoptera: 

Sesiidae)

Orientation to Pest Persimmon borer, Sannina uroceriformis Walker, is a native North 

American clearwing moth found in the eastern United States. The 

larvae feed in the wood of the lower trunk and tap roots of the American 

persimmon tree, Diospyros virginiana L. Moths emerge in spring and 

mate. Females either lay their eggs on tree bark or drop them at the base 

of the host tree. After hatching, larvae move to suitable parts of the host 

tree and burrow into the bark. Larvae tunnel in the cambium downward, 

and when they are at or near the soil line, tunnel into the wood toward 

the center of the tap or lateral roots. Larvae overwinter in their galleries 

below the soil line and when ready to pupate extend their galleries 

upward in the roots to the ground line or just above. Trees growing 

in cutover areas and in hedgerows have higher infestation rates, as do 

young trees in nurseries. The life cycle takes 2-3 years to complete. 

This borer attacks only persimmons, particularly the native wild 

persimmon of the United States (D. virginiana).

This borer occurs is found in the United States along the Atlantic coast 

from New Jersey to Florida, and west to Kansas, Texas, Missouri, Ohio, 

and Indiana. 

Hosts Commonly Attacked

Distribution

Images of 

Persimmon Borer

Figure 1. Adult of 

persimmon borer, 

Sannina uroceriformis. 

(James Solomon, 

USDA Forest Service, 

Bugwood.org)

Figure 2. Larva of 

persimmon borer. 

(James Solomon, 

USDA Forest Service, 

Bugwood.org)
426 Forest Pest Insects in North America:

Images of 

Persimmon Borer

(continued)

Figure 3. Pupation tubes 

of persimmon borer 

pushed out of larval 

galleries. 

(James Solomon, 

USDA Forest Service, 

Bugwood.org)

Figure 4. Galleries of persimmon borer larvae in roots of host tree. (James 

Solomon, USDA Forest Service, Bugwood.org)
A Photographic Guide 427

No natural enemies of this species have been recorded.

http://edis.ifas.ufl.edu/in669; University of Florida fact sheet on biology 

and control. 

http://images.bugwood.org/mediawiki/pdf.cfm?title=Archive:Borers/

Sannina_uroceriformis; Bugwood factsheet.

Solomon, J.D. 1995. Guide to Insect Borers in North American Broadleaf 

Trees and Shrubs. Agriculture Handbook No. AH-706, see p. 56-57. 

USDA Forest Service, Washington, DC: 735 p.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Persimmon Borer

Articles
428 Forest Pest Insects in North America:

118. Poplar Clearwing Borer, Paranthrene dollii (Neumoegen) (Lepidoptera: 

Sesiidae)

Orientation to Pest Poplar clearwing borer, Paranthrene dollii (Neumoegen), is a native 

North American clearwing moth that occurs principally in the southern 

United States, where it infests the base and root-collar area of young 

cottonwoods (Populus) and black willow (Salix nigra Marshall). Eggs 

are laid in bark crevices, and larvae bore in the wood and pith, making 

open tunnels up to 15 cm long. Heavily infested trees are mechanically 

weakened and subject to wind and ice breakage. Damage is sometimes 

severe in cottonwood plantations and nurseries, and in the southern states 

losses may reach 12 percent of nursery stock. There is one generation 

per year. 

This borer attacks cottonwoods (Populus) and black willow (S. nigra).

This borer occurs in the southern United States, from Florida to Texas. 

Hosts Commonly Attacked

Distribution

Images of 

Poplar Clearwing Borer

Figure 1. Adult of 

poplar clearwing borer, 

Paranthrene dollii. 

(James Solomon, 

USDA Forest Service, 

Bugwood.org)

Figure 2. Larva of poplar 

clearwing borer. 

(James Solomon, 

USDA Forest Service, 

Bugwood.org)
A Photographic Guide 429

Images of Poplar 

Clearwing Borer (continued)

Figure 3. Frass being 

expelled from larval 

tunnels of poplar 

clearwing borer. 

(James Solomon, 

USDA Forest Service, 

Bugwood.org)

Figure 4. Enlarged 

entrance holes in stem 

of cottonwood seedling, 

caused by larvae of 

Paranthrene dollii. 

(USDA Forest Service 

Fact Sheet)
430 Forest Pest Insects in North America:

Important Biological Control 

Agents Related to this 

Pest Species

One braconid, Apanteles paranthrenidis Muesebeck, is known from this 

borer’s larvae.

http://www.forestpests.org/nursery/cwborers.html; USDA Forest Service 

bulletin on biology and control of several cottonwood borers, including 

P. dollii. 

http://wiki.bugwood.org/Archive:Borers/Paranthrene_dollii; Bugwood 

Wiki fact sheet giving details of biology.

Eroles-Harkins, L. 1983. Biology and life history of the cottonwood 

clearwing borer, Paranthrene dollii (Neum.) (Lepidoptera: Sesiidae), 

in the laboratory and a cottonwood nursery in Mississippi. MS thesis. 

Mississippi State University. 106 p.

Nebeker, T.E. and L. Eroles-Harkins. 1988. Daily and seasonal flight 

of male Paranthrene dollii (Lepidoptera: Sessiidae), monitored by 

pheromone traps. Florida Entomologist 71(3): 376-380.

Web Links for Information 

on Poplar Clearwing Borer

Articles
A Photographic Guide 431

119. Carpenterworm, Prionoxystus robiniae (Peck.) (Lepidoptera: Cossidae)

Orientation to Pest Carpenterworm, Prionoxystus robiniae (Peck.), is a native, wood-boring 

moth that attacks various hardwoods. Adults emerge between May and 

August and lay their eggs in large groups (200-1,000) on bark of hosts, 

often near wounds or objects on the bark such as vines or moss. Young 

larvae bore into the inner bark and feed there until half grown, at which 

time they bore into the sapwood and then the heartwood. In southern 

part of this species’ range, immature stages may complete development 

in a single year, but in northern areas as many as 3 or 4 years may be 

required. Tunnels to the outside are kept open and enlarged as larvae 

grow. Tunnels are lined with silk by mature larvae and pupation occurs 

in the upper end of the tunnel near the exit hole. Pupae, when ready 

for adult emergence, wriggle to the exit where the adult emerges. The 

pupal case remains at the entrance of this exit hole. Carpenterworms 

seldom kill trees, but due to tunneling, infested trees are more likely to 

break in wind storms, may become more vulnerable to other pests, and 

the value of affected logs is reduced. No tree size preference has been 

noted for attack, with trees as small of 5 cm in diameter being infested. 

However, open grown trees, especially trees in urban landscapes and 

rural shelterbelts, are at greatest risk of attack.

In the southern United States, oaks (Quercus), particularly members 

of the red oak group, are heavily damaged. In the prairies and Rocky 

Mountains of North America, poplar species (Populus) and green ash 

(Fraxinus pennsylvanica Marshall) are major hosts. In California, live 

oak (Quercus agrifolia Née) and introduced elms (Ulmus) are hosts. 

Other hosts include black locust (Robinia pseudoacacia L.), maple 

(Acer), and willow (Salix), among others. 

This borer is widely distributed in the United States and southern 

Canada.

Images of 

Carpenterworm

Figure 1. Adults of 

the carpenterworm, 

Prionoxystus robiniae; 

female (left) and male 

(right). (James Solomon, 

USDA Forest Service, 

Bugwood.org)

Hosts Commonly Attacked

Distribution
432 Forest Pest Insects in North America:

Images of 

Carpenterworm

(continued)

Figure 2. Female carpenterworm, center, in natural position. (Gerald J. Lenhard, 

Louiana State Univ, Bugwood.org)

Figure 3. Larvae of 

carpenterworm. (Top: 

William H. Hoffard, 

USDA Forest Service, 

Bugwood.org; bottom: 

James Solomon, 

USDA Forest Service, 

Bugwood.org)
A Photographic Guide 433

Images of 

Carpenterworm

(continued)

Figure 4. Larval gallery 

of carpenterworm (top) 

and surface injury from 

lateral gallery in trunk 

(bottom). (Both photos: 

James Solomon, 

USDA Forest Service, 

Bugwood.org)

Figure 5. Staining 

and oozing are 

signs marking the 

point of entrance for 

carpenterworms. (Larry 

R. Barber, USDA Forest 

Service, Bugwood.org)
434 Forest Pest Insects in North America:

Images of 

Carpenterworm

(continued)

Figure 6. Tunnels of carpenterworms in elm (left) and ash (right) logs at harvest. 

(Left: USDA Forest Service - Ogden Archive, USDA Forest Service, Bugwood.org; 

right: Theodor D. Leininger, USDA Forest Service, Bugwood.org)

Figure 7. Defects 

in milled wood from 

carpenterworm tunnels 

and staining. 

(James Solomon, 

USDA Forest Service, 

Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

Little is know about the natural control of carpenterworms. Woodpeckers 

prey on larvae. Parasitism appears to be minimal.
A Photographic Guide 435

http://wiki.bugwood.org/Archive:Borers/Prionoxystus_robiniae; 

Bugwood wiki fact sheet on biology and control.

http://entomology.unl.edu/ornamentals/pestprofiles/carpenterworm.

shtml; fact sheet of the University of Nebraska.

http://imfc.cfl.scf.rncan.gc.ca/insecte-insect-eng.asp?geID=8249&ind=C; 

fact sheet of Natural Resources Canada.

http://www.entomology.ualberta.ca/searching_species_details.

php?s=2294; University of Alberta insect collection species page.

McKnight, M.E. and S. Tunnock. 1973. The borer problem in green ash 

in North Dakota shelterbelts. Shelterbelt Laboratory, Rocky Mountain 

Forest & Range Experiment Station, Forest Service, USDA, Bottineau, 

North Dakota, USA. North Dakota Farm Research 30(5): 8-14.

Solomon, J.D. and C.J. Hay. 1974. Annotated bibliography of the 

carpenterworm, Prionoxystus robiniae. USDA Forest Service General 

Technical Report SO-4, Southern Forest Experiment Station: 13 p.

Forschler, B.T. and G.L. Nordin. 1998. Suppression of carpenterworm, 

Prionoxystus robiniae (Lepidoptera: Cossidae), with the entomophagous 

nematodes, Steinernema feltiae and S. bibionis. Journal of the Kansas 

Entomological Society 61: 396-400. 

Web Links for Information 

on Carpenterworm

Articles
436 Forest Pest Insects in North America:

120. Pecan Carpenterworm, Cossula magnifica (Stecker) (Lepidoptera: 

Cossidae)

Orientation to Pest Pecan carpenterworm, Cossula magnifica (Stecker), is a native wood 

boring moth that occurs throughout the southeastern United States, where 

it reproduces in pecan (Carya illinoinensis [Wangenh.] K. Koch), oak 

(Quercus), and hickory (Carya). Adults emerge in spring and lay their 

eggs on bark of small twigs. Young larvae bore in the pith of twigs. 

Larger larvae move into the branches or the trunk, where they excavate 

tunnels several inches in length. Frass is expelled through the larval 

tunnel, which is kept open and enlarged as the larva grows. Pupation 

occurs in the larval tunnel in the spring. There is one generation per year. 

This borer attacks pecan (C. illinoinensis), oak (Quercus), and hickory 

(Carya).

This borer occurs in the southeastern United States. 

Hosts Commonly Attacked

Distribution

Images of 

Pecan Carpenterworm

Figure 1. Adult of pecan carpenterworm, Cossula magnifica; right, in natural 

pose. (Left: James Solomon, USDA Forest Service, Bugwood.org; right: 

Theresa Thom, U.S. National Park Service)

Figure 2. Larva of pecan 

carpenterworm. 

(James Solomon, 

USDA Forest Service, 

Bugwood.org)
A Photographic Guide 437

Images of 

Pecan Carpenterworm

(continued)

Figure 3. Entrance of pecan carpenterworm tunnel in twig. (James Solomon, 

USDA Forest Service, Bugwood.org)

Figure 4. Larval tunnels 

of pecan carpenterworm 

seen in longitudinal 

section in pieces of 

milled wood. 

(James Solomon, 

USDA Forest Service, 

Bugwood.org)
438 Forest Pest Insects in North America:

Images of 

Pecan Carpenterworm

(continued)

Figure 5. Frass pellets 

and staining below the 

tunnel opening of the 

pecan carpenterworm. 

(James Solomon, 

USDA Forest Service, 

Bugwood.org)

Figure 6. Larval tunnels 

of pecan carpenterworm 

seen in cross section in 

a log. (James Solomon, 

USDA Forest Service, 

Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

Two tachinid parasitoids—Phorocera comstocki Williston and Phorocera 

signata Aldrich and Webber—have been reared from this species, but not 

much is known of their effects on the insect’s population dynamics. 

http://wiki.bugwood.org/Archive:Borers/Cossula_magnifica; fact sheet 

of Bugwood Wiki on biology and control. 

None

Web Links for Information 

on Pecan Carpenterworm

Articles
A Photographic Guide 439

121. Spruce Budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: 

Tortricidae)

Orientation to Pest Spruce budworm, Choristoneura fumiferana (Clemens), is a native North 

American moth whose larvae feed on balasam fir (Abies balsamea

[L. Mill.), white (Picea glauca [Moench] Voss), red (P. rubens Sarg.), 

and black spruce (P. mariana [Mill.] Britton, Sterns & Poggenburg), and 

sometimes larch (Larix), pine (Pinus), and hemlock (Tsuga). Adults fly in 

summer and deposits masses of eggs (2-60) on needles in the periphery 

of the host tree’s crown. Eggs hatch and produce larvae that create a 

hibernacula in which they overwinter as second instars. Hibernaculae 

are found on branches and other sites on or near the host tree. In the 

spring of the following year, larvae emerge at or before bud break, 

disperse aerially, and begin to feed. Buds of staminate flowers are eaten 

if available, and then old needles are consumed. Larvae then feed on the 

new vegetative buds, and later, the new foliage. When about half grown, 

larvae tie several branch tips together with silk to make a nest, where 

mature larvae later pupate. Females deposit eggs before flying to new 

sites. Defoliation events from this moth occur regularly over wide areas 

in eastern Canada and economic losses can be great if uncontrolled. The 

population dynamics of this species have been the focus of extensive 

and intense investigation for many decades. For a general review of 

economic losses and population dynamics see Van Driesche et al. (1996) 

under articles below. 

Balsam fir (A. balsamea [L.] Mill.) is the preferred host of this 

species, but it also feeds on white (P. glauca [Moench] Voss), red 

(P. rubens Sarg.), and black spruce (P. mariana [Mill.] Britton, Sterns 

& Poggenburg), as well as to some degree on species of larch (Larix), 

pine (Pinus), and hemlock (Tsuga). 

This moth is found throughout the range of its main hosts (balsam fir 

and white spruce) from Virginia to Labrador and west to Alaska. Related 

budworms are found in the western part of North America that were 

formerly thought to be the same species but now are considered distinct 

species. Damage in the United States is concentrated along the northern 

tier of states in the eastern half of the country, from Maine to Minnesota.

Hosts Commonly Attacked

Distribution
440 Forest Pest Insects in North America:

Images of Spruce Budworm

Figure 1. Adults of spruce budworm, Choristoneura fumiferana. (K.B. Jamieson, 

Canadian Forest Service, Bugwood.org)

Figure 2. Eggs of spruce budworm on needle. (USDA Forest Service - 

Northeastern Area Archive, USDA Forest Service, Bugwood.org)
A Photographic Guide 441

Images of Spruce Budworm

(continued)

Figure 3. Young larva 

of spruce budworm 

hanging from thread, 

preparing for dispersal 

by wind. (Jerald E. 

Dewey, USDA Forest 

Service, Bugwood.org)

Figure 4. Mature larva of spruce budworm. (Connecticut Agricultural Experiment 

Station Archive, Connecticut Agricultural Experiment Station, Bugwood.org)
442 Forest Pest Insects in North America:

Images of Spruce Budworm

(continued)

Figure 5. Nests of 

mature spruce budworm 

larvae. (Top: A. Steven 

Munson, USDA Forest 

Service, Bugwood.org; 

bottom: Joseph O’Brien, 

USDA Forest Service, 

Bugwood.org)

Figure 6. Pupa of spruce budworm (left) and cast pupal skin (right). (Both photos: 

USDA Forest Service - Ogden Archive, USDA Forest Service, Bugwood.org)

Figure 7. Needle mining 

damage caused by 

young larva of spruce 

budworm. (USDA 

Forest Service - Ogden 

Archive, USDA Forest 

Service, Bugwood.org)
A Photographic Guide 443

Images of Spruce Budworm

(continued)

Figure 8. Needle feeding 

damage caused by 

older larvae of spruce 

budworm. (USDA 

Forest Service - Ogden 

Archive, USDA Forest 

Service, Bugwood.org)

Figure 9. Damage (browning) to stand of host trees by spruce budworms. 

(A. Steven Munson, USDA Forest Service, Bugwood.org)

Figure 10. Aerial pesticide applications to large areas damaged by spruce 

budworm. (Jerald E. Dewey, USDA Forest Service, Bugwood.org)
444 Forest Pest Insects in North America:

Important Biological Control 

Agents Related to this 

Pest Species

More than 90 species of parasitoids are known to attack spruce budworm 

in Canada. In Van Driesche et al. (1996) there are details about some 

of these species and references to their life histories. In addition, some 

predator groups (birds) are believed to be important to the population 

dynamics of spruce budworm. While some 15 species of pathogens 

attack spruce budworm, none are important in the natural population 

dynamics of the pest. However, one species, Bacillus thuringiensis

Berliner, is applied as a biopesticide for areawide control, having 

fewer nontarget impacts on native species than conventional pesticides. 

Hypotheses concerning the causes driving changes in spruce budworm 

numbers are discussed in Van Driesche et al. (1996). It is widely believed 

that one important influence is variation in spring weather that leads to 

different degrees of synchrony between spring larval emergence and bud 

break of host trees, with late bud break being unfavorable. 

http://www.na.fs.fed.us/spfo/pubs/fidls/sbw/budworm.htm; USDA Forest 

Service Pest and Disease leaflet covering biology and control.

http://en.wikipedia.org/wiki/Spruce_Budworm; Wikipedia article with 

links to other Choristoneura species.

http://www.sampforestpest.ento.vt.edu/defoliating/spruce-budworm/

index.php; links to other documents related to sampling spruce budworm 

in various contexts.

http://imfc.cfl.scf.rncan.gc.ca/insecte-insect-eng.asp?geID=12018; fact 

sheet of Natural Resources Canada.

http://www.entomology.ualberta.ca/searching_species_details.

php?s=5272#; contains information on taxonomy of this species.

Van Driesche, R.G., S. Healy, and R.C. Reardon. 1996. Biological 

Control of Arthropod Pests of the Northeastern and North Central 

Forests in the United States: A review and recommendations. FHTET 

96-19, December 1996, USDA Forest Service, Morgantown, WV; 

see http://www.forestpestbiocontrol.info/fact_sheets/documents/

arthropodpestsnortheastern_northcentral.pdf.

Web Links for Information 

on Spruce Budworm

Articles
A Photographic Guide 445

122. Jack Pine Budworm, Choristoneura pinus pinus Freeman 

(Lepidoptera: Tortricidae)

Orientation to Pest Jack pine budworm, Choristoneura pinus pinus Freeman, is closely 

related to eastern spruce budworm, Choristoneura fumiferana

(Clemens), and is part of a complex of eight closely related species (see 

Lumley et al. 2010, 2011 below). Jack pine budworm is a native North 

American moth found in eastern Canada, westward to Alberta and in 

the northeastern and north central United States. Its larvae feed various 

pines, especially jack (Pinus banksiana Lamb.) and red (P. resinosa Sol. 

ex Aiton) pine. Adults fly in mid-to-late summer and lay their eggs in 

clusters (about 40) on needles. Eggs hatch and the young larvae, without 

feeding, create hibernaculae under the bark scales on tree trunks or limbs, 

or between needles. They then molt to second instars and overwinter. 

In the spring of the following year, larvae emerge near the time when 

staminate flower buds begin to swell. Staminate flowers are usually the 

larvae’s first food, and thereafter most larvae move to new foliage, where 

they feed and develop. Needles are clipped and webbed together by older 

larvae, and needles are only partially consumed. Pupation occurs among 

the needles or webbed shoots. Feeding of jack pine budworm usually 

does not kill attacked trees, but may cause top killing and deform the 

tree, reducing quality of logs for lumber purposes. During outbreaks, 

younger trees may be killed outright. For further information see Van 

Driesche et al. (1996). 

Jack pine budworm larvae feed on various pines, but especially jack 

(P. banksiana) and red (P. resinosa) pine.

This moth is found in Canada throughout the range of jack pine, from 

the Maritimes west to Alberta. In the United States, it is found in the 

northeastern and north central parts of the country, from New England to 

the Great Lakes states.

Hosts Commonly Attacked

Distribution

Figure 1. Adult of 

jack pine budworm, 

Choristoneura pinus 

pinus. (USDA Forest 

Service - Northeastern 

Area Archive, USDA 

Forest Service, 

Bugwood.org)

Images of 

Jack Pine Budworm
446 Forest Pest Insects in North America:

Images of Jack Pine 

Budworm (continued)

Figure 2. Hatched 

egg mass (shiny area 

on central needle) of 

jack pine budworm. 

(USDA Forest Service 

- Northeastern Area 

Archive, USDA Forest 

Service, Bugwood.org)

Figure 3. Young larvae of jack pine budworm, feeding on male flower of host 

plant. (D.M. Benjamin, University of Wisconsin, Bugwood.org)
A Photographic Guide 447

Images of Jack Pine 

Budworm (continued)

Figure 4. Mature larva of jack pine budworm. (Steven Katovich, USDA Forest 

Service, Bugwood.org)

Figure 5. Pupa of jack pine budworm, in area webbed by larvae. 

(Steven Katovich, USDA Forest Service, Bugwood.org)

Figure 6. Webbing and feeding on shoots of host by jack pine budworm larvae. 

(Minnesota Department of Natural Resources Archive, Minnesota Department of 

Natural Resources, Bugwood.org)
448 Forest Pest Insects in North America:

Images of Jack Pine 

Budworm (continued)

Figure 7. Damage (see browning) to stand of host trees by jack pine budworm 

larvae. (James B. Hanson, USDA Forest Service, Bugwood.org)

Figure 8. Damage to 

understory seedling pine 

by jack pine budworm. 

(Minnesota Department 

of Natural Resources 

Archive, Minnesota 

Department of 

Natural Resources, 

Bugwood.org)
A Photographic Guide 449

Images of Jack Pine 

Budworm (continued)

Figure 9. Aerial view of area defoliated by jack pine budworm. (A. Steven 

Munson, USDA Forest Service, Bugwood.org)

From 13 to 46 parasitoid species have been recovered in studies of 

jack pine budworms in various locations (see Van Driesche et al. 1996 

for more detail). The species of greatest importance appear to be the 

larval parasitoids Apanteles fumiferanae Viereck (Braconidae) and 

Glypta fumiferana (Viereck) (Ichneumonidae), and the pupal parasitoid 

Itoplectis conquisitor (Say) (Ichneumonidae). The abundance of male 

flowers in a stand is believed to be linked to outbreaks of this species 

(see Van Driesche et al. 1996 for a discussion of the literature on this 

point). 

http://www.na.fs.fed.us/spfo/pubs/howtos/ht_jack/ht_jack.htm; USDA 

Forest Service fact sheet on biology and management.

http://en.wikipedia.org/wiki/Jack_Pine; Wikipedia article on basic 

biology.

http://www.entomology.ualberta.ca/searching_species_print.

php?s=5271&sn=; provides details on the taxonomy of this species. 

Van Driesche, R.G., S. Healy, and R.C. Reardon. 1996. Biological 

Control of Arthropod Pests of the Northeastern and North Central 

Forests in the United States: A review and recommendations. FHTET 

96-19, December 1996, USDA Forest Service, Morgantown, WV; 

see http://www.forestpestbiocontrol.info/fact_sheets/documents/

arthropodpestsnortheastern_northcentral.pdf.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Jack Pine Budworm

Articles
450 Forest Pest Insects in North America:

Lumley, L.M. and F.A.H. Sperling. 2010. Integrating morphology and 

mitochondrial DNA for species delimitation within the spruce budworm 

(Choristoneura fumiferana) cryptic species complex (Lepidoptera: 

Tortricidae). Systematic Entomology 35: 416-428.

Nealis, V.G. 1991. Parasitism in sustained and collapsing populations of 

the jack pine budworm, Choristoneura pinus pinus Free. (Lepidoptera: 

Tortricidae), in Ontario, 1985-1987. The Canadian Entomologist 123: 

1065-1075. 

Lumley, L.A. and F.A.H. Sperling. 2011. Utility of microsatellites and 

mitochondrial DNA for species delimitation in the spruce budworm 

(Choristoneura fumiferana) species complex (Lepidoptera: Tortricidae). 

Molecular Phylogenetics and Evolution 58: 232-243. 

Articles on Jack Pine 

Budworm (continued)
A Photographic Guide 451

123. Large Aspen Tortrix, Choristoneura conflictana (Walker) (Lepidoptera: 

Tortricidae)

Large aspen tortrix, Choristoneura conflictana (Walker), is a native 

North American tortricid moth found throughout the range of quaking 

aspen (Populus tremuloides Michx.) in Canada and the United States. 

In Canada, adults lay their eggs in June or July in flat clusters, usually 

on the leaves. Eggs hatch and the first instars feed together on leaves, 

webbing foliage together. Fed first instars then move to the trunk where 

they create hibernaculae and overwinter as second instars. In the spring 

of the following year, larvae emerge and feed by mining the swelling 

buds. Later, larvae feed in leaf rolls. Pupation occurs in the leaf rolls, 

and adults emerge in a few weeks to lay eggs of the new generation. 

Defoliating outbreaks have occurred in the aspen stands in Canada, 

Alaska, New England, New York, and Michigan. Reasons for outbreaks 

have not been studied, but the existence of overwintering young larvae 

that feed on buds the following year suggests that variation in the degree 

of synchrony (driven by annual weather events) between bud break and 

larvae resumption of feeding is likely to be a factor. 

The large aspen tortrix is mainly associated with quaking aspen 

(P. tremuloides) but also feeds on balsam poplar (Populus sect. 

tacamahaca), bigtooth aspen (P. grandidentata Michaux), paper birch 

(Betula papyrifera Marsh.), willow (Salix), and alder (Alnus). 

This moth is found throughout the range of quaking aspen in Canada and 

the United States.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Figure 1. Adult of large aspen tortrix, Choristoneura conflictana. (Steven 

Katovich, USDA Forest Service, Bugwood.org)

Images of Large

Aspen Tortrix
452 Forest Pest Insects in North America:

Images of Large Aspen 

Tortrix (continued)

Figure 2. Egg mass 

of large aspen tortrix. 

(Steven Katovich, 

USDA Forest Service, 

Bugwood.org)

Figure 3. Young larvae 

of large aspen tortrix, 

feeding on webbed 

leaves. (Minnesota 

Department of Natural 

Resources Archive, 

Minnesota Department 

of Natural Resources, 

Bugwood.org)
A Photographic Guide 453

Images of Large Aspen 

Tortrix (continued)

Figure 5. Rolled leaf, 

feeding site of older 

larvae of large aspen 

tortrix. (Steven Katovich, 

USDA Forest Service, 

Bugwood.org)

Figure 4. Mature larva of large aspen tortrix. (William M. Ciesla, Forest Health 

Management International, Bugwood.org)
454 Forest Pest Insects in North America:

Images of Large Aspen 

Tortrix (continued)

Figure 6. Pupa of large 

aspen tortrix. 

(William M. Ciesla, 

Forest Health 

Management 

International, 

Bugwood.org)

Figure 7. Quaking aspen 

defoliated by large 

aspen tortrix. 

(William M. Ciesla, 

Forest Health 

Management 

International, 

Bugwood.org)
A Photographic Guide 455

Images of Large Aspen 

Tortrix (continued)

Figure 8. Aerial view of area defoliated by large aspen tortrix. (USDA Forest 

Service - Region 2 - Rocky Mountain Region Archive, USDA Forest Service, 

Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

A large number of species of parasitoids (>20) have been reared from 

larvae and pupae in several locations where studies have been conducted 

(Alberta, Canada; Alaska). Collectively, these cause significant levels 

of mortality, up to 50 percent in some cases. Among the more important 

species are Macrocentrus iridescens French, Glypta inversa Cresson, 

Glypta fumiferanae (Viereck), and Agathis annulipes (Cresson). 

http://imfc.cfl.scf.rncan.gc.ca/insecte-insect-eng.asp?geID=12016; fact 

sheet of Natural Resources Canada.

http://www.fs.fed.us/r10/spf/fhp/leaflets/Larasptor.htm; USDA Forest 

Service fact sheet.

http://www.fs.fed.us/r10/spf/fhp/leaflets/Fidl139.htm; USDA Forest 

Service leaflet.

http://www.entomology.ualberta.ca/searching_species_details.

php?s=5251; fact sheet of the University of Alberta.

Torgersen, T.R. and R.C. Beckwith. 1974. Parasitoids associated with the 

large aspen tortrix, Choristoneura conflictana (Lepidoptera: Tortricidae), 

in interior Alaska. The Canadian Entomologist 106: 1247-1265.

Jones, B.C., J. Roland, and M.L. Evenden. 2009. Development of a 

combined sex pheromone-based monitoring system for Malacosoma 

disstria (Lepidoptera: Lasoicampidae) and Choristoneura conflictana

(Lepidoptera: Tortricidae). Environmental Entomology 38: 459-471.

Web Links for Information 

on Large Aspen Tortrix

Articles
456 Forest Pest Insects in North America:

124. Sugar Pine Tortrix, Choristoneura lambertiana Busck (Lepidoptera: 

Tortricidae)

Orientation to Pest Sugar pine tortrix, Choristoneura lambertiana Busck, is a tortricid 

moth native to western North American that feeds on various conifers, 

especially pines. This species includes many different races that vary 

in appearance or aspects of biology, some of which have been given 

subspecies names. This moth’s life history is similar to that of other 

better known members of the genus. Adults fly in summer (July and 

August) and lay eggs on the foliage of the host plant. Young larvae 

overwinter in hibernaculae on the tree trunk and reemerge the following 

spring when they feed by mining needle sheaths and staminate cones. 

New foliage buds are also consumed. Several larvae (1-5) may feed 

together on the same shoot. Larvae web the needles into feeding shelters 

and pupae are formed among the webbed needles. Damaged trees are not 

likely to die, but tops may be killed. 

The sugar pine tortrix feeds on various pines, including sugar (Pinus 

lambertiana Douglas), lodgepole (P. contorta Douglas), limber (P. flexilis

E. James), and ponderosa (P. ponderosa Douglas ex. C. Lawson) pines, 

as well as some other conifers, including Douglas-fir (Pseudotsuga 

menziesii [Mirb.] Franco) and juniper (Juniperus). 

This moth is found in several western U.S. states (including California, 

Colorado, Idaho, Montana, Oregon, and Montana). Ranges by subspecies 

have been recorded as follows: Choristoneura lambertiana lambertiana

(confirmed: Siskiyou County and Ashland, Oregon; uncertain: Alberta 

and British Columbia in Canada and Idaho, Montana, eastern Oregon, 

and Wyoming in the United States); C. lambertiana ponderosana

(Arizona, Colorado, Nevada, New Mexico, western New England, South 

Dakota); C. lambertiana subretiniana (California and Oregon).

Figure 1. Adults (two forms with different color patterns) of the sugar pine 

tortrix, Choristoneura lambertiana. (Left: Mark McGregor, USDA Forest Service, 

Bugwood.org; right: USDA Forest Service - Ogden Archive, USDA Forest 

Service, Bugwood.org)

Images of 

Sugar Pine Tortrix

Hosts Commonly Attacked

Distribution
A Photographic Guide 457

Images of Sugar Pine 

Tortrix (continued)

Figure 2. Egg mass of the sugar pine tortrix. (USDA Forest Service - 

Northeastern Area Archive, USDA Forest Service, Bugwood.org)

Figure 3. Larvae of 

the sugar pine tortrix. 

(Top: Scott Tunnock, 

USDA Forest Service, 

Bugwood.org; bottom: 

Bernard J. Raimo, 

USDA Forest Service, 

Bugwood.org)
458 Forest Pest Insects in North America:

Images of Sugar Pine 

Tortrix (continued)

Figure 4. Needles that have been clipped and webbed together by sugar pine 

tortrix larvae. (Left: Scott Tunnock, USDA Forest Service, Bugwood.org; right: 

USDA Forest Service - Ogden Archive, USDA Forest Service, Bugwood.org)

Figure 5. Pupa of the 

sugar pine tortrix (top) 

and skin of emerged 

pupa (bottom). (Top: 

USDA Forest Service 

- Ogden Archive, 

USDA Forest Service, 

Bugwood.org; bottom: 

Bernard J. Raimo, 

USDA Forest Service, 

Bugwood.org)
A Photographic Guide 459

Images of Sugar Pine 

Tortrix (continued)

Figure 6. Damage to tips of small pine from larvae of the sugar pine tortrix. 

(Dave Powell, USDA Forest Service, Bugwood.org)

As with other Chorisoneura species, the sugar pine tortrix is affected by 

a large complex of natural enemies, especially parasitoids, of which some 

22 species are known from rearing. However, the effect, if any, of these 

species on fluctuations in density of this pest is unknown. 

http://www.ireference.ca/search/Choristoneura%20lambertiana/; 

discusses host plants of some of the subspecies of the sugar pine tortrix.

http://en.wikipedia.org/wiki/Choristoneura_lambertiana; Wikipedia 

articles includes information on ranges of subspecies.

http://www.ext.colostate.edu/pubs/insect/05567.html; factsheet of 

Colorado State University giving general information of subspecies 

associated with ponderosa pine.

Stevens, R.E., T.K. Borg, and T.O. Thatcher. 1977. Notes on a 

pine-feeding budworm, Choristoneura lambertiana ponderosana

(Lepidoptera: Tortricidae), in the Colorado Rockies. The Canadian 

Entomologist 109: 1269-1274.

Powell, J.A. 1995. Biosystematic Studies of Conifer-feeding 

Choristoneura (Lepidoptera: Tortricidae) in the Western United States.

University of California Publications, Entomology, Berkeley, California. 

(Contains range information.)

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Sugar Pine Tortrix

Articles
460 Forest Pest Insects in North America:

125. Western Spruce Budworm, Choristoneura occidentalis Freeman 

(Lepidoptera: Tortricidae)

Orientation to Pest Western spruce budworm, Choristoneura occidentalis Freeman, 

is a tortricid moth native to western North American that feeds on 

various conifers, including species of fir (Abies), larch (Larix), spruce 

(Picea), and Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco). 

The life history of this moth is similar to that of the spruce budworm 

(Choristoneura fumiferana [Clemens]). Adults fly and lay eggs in 

summer (July and August) on the host plant. Young larvae do not feed 

but rather immediately spin a hibernacula under bark scales, where they 

overwinter. The next spring, larvae become active and feed by mining 

old needles until the buds swell. Larvae then bore into the buds and feed 

on the expanding needles. Later in the spring, they loosely web together 

growing tips and feed upon the new needles, where they later pupate. 

There is one generation per year. This is considered one of the most 

damaging pests in western North American forests, and large, sustained 

outbreaks sometimes occur. Damaged trees may be killed entirely or just 

the tops may die, destroying the commercial value of the trees. 

This species feeds on various confers including Abies concolor (Gordon) 

Lindley ex Hildebrand, A. grandis (Douglas ex D. Don) Lindley, 

A. lasiocarpa (Hooker) Nuttall, Larix occidentalis Nutt., Picea 

engelmannii Parry ex Engelm., P. glauca (Moench) Voss, P. pungens

Engelm., Douglas-fir, and juniper (Juniperus). 

This moth is found in several western U.S. states, including Colorado, 

Idaho, Montana, Wyoming, Colorado, Arizona, Utah, New Mexico, 

Oregon, and Washington, as well of British Columbia and southwest 

Alberta, Canada.

Hosts Commonly Attacked

Distribution

Figure 1. Distribution 

of the western spruce 

budworm, Choristoneura 

occidentalis, in western 

North America. (USDA 

Forest Service • 

Forest Insect & 

Disease Leaflet 53) 
A Photographic Guide 461

Images of Western

Spruce Budworm

Figure 2. Adult of the western spruce budworm. (USDA Forest Service - Region 4 

- Intermountain Archive, USDA Forest Service, Bugwood.org)

Figure 3. Silvery egg mass of the western spruce budworm on needle. (USDA 

Forest Service - Region 2 - Rocky Mountain Region Archive, USDA Forest 

Service, Bugwood.org)

Figure 4. Very young larva of western spruce budworm feeding in bud (left) and 

on new foliage (right). (Both photos: USDA Forest Service - Region 2 - Rocky 

Mountain Region Archive, USDA Forest Service, Bugwood.org)
462 Forest Pest Insects in North America:

Images of Western

Spruce Budworm

(continued)

Figure 5. Webbed foliage, the feeding site of young larvae of the western spruce 

budworm. (Ladd Livingston, Idaho Department of Lands, Bugwood.org)

Figure 6. Mature larva of western spruce budworm. (Scott Tunnock, USDA Forest 

Service, Bugwood.org)

Figure 7. Pupae of the western spruce budworm. (Left: USDA Forest Service - 

Region 2 - Rocky Mountain Region Archive, USDA Forest Service, Bugwood.org; 

right: David McComb, USDA Forest Service, Bugwood.org)
A Photographic Guide 463

Images of Western

Spruce Budworm

(continued)

Figure 8. Damage 

caused by western 

spruce budworm to a 

grand fir. 

(William M. Ciesla, 

Forest Health 

Management 

International, 

Bugwood.org)

Figure 9. Stand of grand fir in Oregon defoliated by western spruce budworm. 

(William M. Ciesla, Forest Health Management International, Bugwood.org)
464 Forest Pest Insects in North America:

Images of Western

Spruce Budworm

(continued)

Figure 10. Stand with dead trees 10 years after a western spruce budworm 

outbreak in Oregon. (Dave Powell, USDA Forest Service, Bugwood.org)

Figure 11. Eggs of western spruce budworm parasitized by the egg parasitoid 

Trichogramma minutum Riley. (USDA Forest Service - Region 2 - Rocky 

Mountain Region Archive, USDA Forest Service, Bugwood.org)

As with other Choristoneura species, the western spruce budworm is 

affected by a large complex of natural enemies, especially parasitoids, 

which, along with adverse weather, partially limit the pest’s density. 

However, population outbreaks occur when climatic and forest stand 

conditions are favorable. There are more than 40 species of insect 

parasitoids of the western spruce budworm, of which four or five species 

are most common. See Bellows et al. (1998) for species names.

Important Biological Control 

Agents Related to this 

Pest Species
A Photographic Guide 465

Web Links for Information 

on Western Spruce Budworm

http://www.na.fs.fed.us/spfo/pubs/fidls/westbw/fidl-wbw.htm; USDA 

Forest Service fact sheet covering biology, control and other topics.

http://www.ext.colostate.edu/pubs/insect/05543.html; fact sheet of 

Colorado State University.

http://ext.nrs.wsu.edu/forestryext/foresthealth/notes/westernbudworm.

htm; fact sheet of Washington State University. 

http://www.oregon.gov/ODF/privateforests/docs/fh/

WesternSpruceBudworm.pdf?ga=t; fact sheet of the Oregon Department 

of Forestry.

Schmidt, W.C. and D.C. Fellin. 1973. Western spruce budworm damage 

affects form and height growth of western larch. Canadian Journal of 

Forest Research 3(1): 17-26. 

Jennings, D.T., F.B. Knight, S.C. Hacker, and M.E. McKnight. 1979. 

Spruce budworms bibliography. Misc. Rep. 213. University of Maine, 

School of Forest Resources, Life Science and Agricultural Experiment 

Station. Orono, Maine: 687 p. 

Bellows, T.S., C. Meisenbacher, and R.C. Reardon. 1998. Biological 

Control of Arthropod Forest Pests of the Western United States: A 

review and recommendations. FHTET-96-21. USDA Forest Service, 

Morgantown, West Virginia, USA.

Articles
466 Forest Pest Insects in North America:

126. Spruce Bud Moth, Zeiraphera canadensis Mutuura and Freeman 

(Lepidoptera: Tortricidae)

Orientation to Pest Spruce bud moth, Zeiraphera canadensis Mutuura and Freeman, is a 

native tortricid moth associated predominantly with spruce (Picea) in 

eastern North America. It overwinters as eggs, which hatch in the spring. 

There are four larval instars. First and second instar larvae mine needles 

of recently burst buds. Third and fourth instars feed on the stems of 

shoots. Pupation usually takes place in the soil. There is one generation 

per year. Larval feeding on shoots of the upper crown and on the leader 

can stunt tree growth, causing economically important damage in spruce 

plantations. Injury is most common on open grown spruces (before 

crown closure) and this species is not a pest in natural forest stands. 

This moth feeds mainly on white spruce (Picea glauca [Moench]), but 

sometimes attacks black spruce (P. mariana [Mill.] Britton, Sterns and 

Poggenburg) or balsam fir (Abies balsamea [L.] Mill.). 

This moth occurs throughout the range of spruce in the northern United 

States and eastern Canada.

Hosts Commonly Attacked

Distribution

Figure 1. Adult of spruce bud moth, Zeiraphera canadensis Mutuura and 

Freeman. (Bo Zaremba - bozaremba@comcast.net)

Images of 

Spruce Bud Moth
A Photographic Guide 467

Images of Spruce 

Bud Moth (continued)

Figure 2. Parasitized 

egg of spruce bud 

moth (black) at base of 

shoot. (Thérèse Arcand 

- Natural Resources 

Canada, Canadian 

Forest Service)

Figure 3. Mature larva 

of spruce bud moth. 

(Dion Manastyrski - 

Pacific Forestry Centre, 

Natural Resources 

Canada, Canadian 

Forest Service)

Figure 4. Buds damaged by spruce bud moth. (Left: Connecticut Agricultural 

Experiment Station Archive, Connecticut Agricultural Experiment Station, 

Bugwood.org; right: Dion Manastyrski - Pacific Forestry Centre, Natural 

Resources Canada, Canadian Forest Service)

Figure 5. Buds damaged 

by spruce bud moth; see 

cap of bud held by silk 

threads. (Jean-François 

Mouton - Natural 

Resources Canada, 

Canadian Forest 

Service)
468 Forest Pest Insects in North America:

In Newfoundland, Canada, the ichneumonid Tycherus osculator

parasitizes up to 50 percent of the larvae of spruce bud moth.

http://imfc.cfl.scf.rncan.gc.ca/insecte-insect-eng.asp?geID=11208; fact 

sheet of Natural Resources Canada, including information on how to 

scout for this pest.

http://www.fs.fed.us/r10/spf/fhp/leaflets/Sprlarbudmot.htm; fact sheet 

of USDA Forest Service, Alaska on Zeiraphera spp. and methods for 

reducing their damage on spruce and larch.

Turgeon, J.J. 1985. Life cycle and behaviour of the spruce bud moth, 

Zeiraphera canadensis (Lepidoptera: Olethreutidae) in New Brunswick. 

The Canadian Entomologist 117: 1239-1247. 

Turgeon, J.J. and J. Régnière. 1987. Development of sampling 

schemes for the spruce bud moth, Zeiraphera canadensis (Lepidoptera: 

Tortricidae). The Canadian Entomologist 119: 239-249.

Turgeon, J.J., N. Nelson, and E.G. Kettela. 1987. Reproductive biology 

of the spruce bud moth, Zeiraphera canadensis (Lepidoptera: Tortricidae: 

Olethreutinae), in New Brunswick. The Canadian Entomologist

119: 361-364.

Carroll, A.L. and D.T. Quiring. 1993. Influence of feeding by Zeiraphera 

canadensis (Lepidoptera: Tortricidae) on growth of white spruce: larval 

density - damage and damage - shoot production relationships. Journal 

of Applied Ecology 30: 629-639.

West, R.J., M. Kenis, G.W. Butt, and S.M. Bennett. 1999. Parasitoid 

complex of Zeiraphera canadensis (Lepidoptera: Tortricidae) and 

evaluation of Tycherus osculator (Hymenoptera: Ichneumonidae) as a 

biological control agent. The Canadian Entomologist 131: 465-474.

West, R.J., M. Kenis, R.S. Bourchier, S.M. Smith, and G.W. Butt. 

2001. Zeiraphera canadensis Mutuura and Freeman, spruce bud 

moth (Lepidoptera: Tortricidae). In: Mason, P.G. and J.T. Huber 

(eds.). Biological Control Programmes in Canada, 1981-2000.

CABI Publishing, Wallingford, UK: 279-283. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Spruce Bud Moth

Articles
A Photographic Guide 469

127. Cottonwood Twig Borer, Gypsonoma haimbachiana (Kearfott) 

(Lepidoptera: Tortricidae)

Orientation to Pest Cottonwood twig borer, Gypsonoma haimbachiana (Kearfott), is a 

native tortricid found throughout the eastern United States and parts 

of southern Canada. It bores in the stems of young eastern cottonwood 

(Populus deltoides Bartr.) and is considered an important pest of young 

cottonwoods that are grown in plantations. Winter is spent as young 

larvae that are found on trees in silk-lined shallow pits excavated in 

healed over borer entrance holes or other depressions on trees. Some 

older larvae overwinter in hollowed-out buds. In spring, larvae bore 

into tender new shoots. After pupation and adult emergence, eggs are 

laid singly or in small groups on the foliage. New larvae of summer 

generations cover themselves with silk mixed with trash, then bore into 

the midrib. After a few days, the larvae abandon their midrib galleries 

and tunnel in shoots to complete their development. In the southern 

United States, there may be four to five generations per year. Damaged 

trees are stunted, crooked, and have many limbs, reducing tree value.

This borer attacks various poplars, especially eastern cottonwood.

Cottonwood twig borer is found in the eastern United States, west to 

Texas and in Ontario, Canada. It is common in the southern United 

States.

Hosts Commonly Attacked

Distribution

Images of 

Cottonwood Twig Borer

Figure 1. Adults of 

the cottonwood twig 

borer, Gypsonoma 

haimbachiana (Kearfott). 

(Top: Jim Vargo; bottom: 

Steve Scott, Illinois 

Eastern Community 

College, Bugwood.org) 
470 Forest Pest Insects in North America:

Images of Cottonwood 

Twig Borer (continued)

Figure 2. Egg of 

cottonwood twig 

borer. (R.C. Morris, 

USDA Forest Service, 

Bugwood.org)

Figure 3. Larvae of cottonwood twig borer. (Both photos: Whitney Cranshaw, 

Colorado State University, Bugwood.org)
A Photographic Guide 471

Images of Cottonwood 

Twig Borer (continued)

Figure 4. Cottonwood twig broken at larval tunnel of cottonwood twig borer. 

(Whitney Cranshaw, Colorado State University, Bugwood.org)

Figure 5. Frass tubes at cottonwood twig borer entrance holes are a sign of this 

pest’s presence. (James Solomon, USDA Forest Service, Bugwood.org)

Some natural enemies of have been noted attacking cottonwood twig 

borer (e.g., those in Steward and Payne (1972) and Steward (1973), cited 

below. Also, see comments in Van Driesche et al. (1996). However, these 

have not been studied sufficiently to get a general understanding of their 

importance or distribution.

Important Biological Control 

Agents Related to this 

Pest Species
472 Forest Pest Insects in North America:

http://wiki.bugwood.org/Archive:South/Gypsonoma_haimbachiana; 

Bugwood Wiki fact sheet on biology.

http://www.fs.fed.us/r8/foresthealth/idotis/insects/cwtwigbr.html; USDA 

Forest Service, Southern Region fact sheet. 

Morris, R.C. 1967. Biology of Gypsonoma haimbachiana (Lepidoptera: 

Olethreutidae), a twig borer in eastern cottonwood. Annals of the 

Entomological Society of America 60: 423-427.

Stewart, J.W. and T.L. Payne. 1972. Parasites and predators of the 

cottonwood twig borer in Texas. Environmental Entomology 1: 669-670.

Stewart, J.W. and T.L. Payne. 1975. Seasonal abundance and impact of 

the cottonwood twig borer on cottonwood trees. Journal of Economic 

Entomology 68: 599-602.

Van Driesche, R.G., S. Healy, and R.C. Reardon. 1996. Biological 

Control of Arthropod Pests of the Northeastern and North Central 

Forests in the United States: A review and recommendations. FHTET 

96-19, December 1996, USDA Forest Service, Morgantown, WV. 

(See http://www.forestpestbiocontrol.info/fact_sheets/documents/

arthropodpestsnortheastern_northcentral.pdf).

McMillin, J.D., M.J. Anderson, E.E. Butin, and E.R. Hart. 1998. 

Phenology and infestation patterns of the cottonwood twig borer 

(Lepidoptera: Tortricidae) in Iowa. Great Lakes Entomologist

31: 181-190.

Web Links for Information 

on Cottonwood Twig Borer

Articles
A Photographic Guide 473

129. Oak Leafroller, Archips semiferanus (Walker) (Lepidoptera: Tortricidae)

Oak leafroller, Archips semiferanus (Walker), is native to North America, 

where it is widely distributed in the eastern half of the continent. Females 

lay eggs in masses of 40 to 50 eggs on branches or rough bark in July. 

Eggs overwinter and larvae emerge in spring and feed on buds and young 

leaves. Mid-to-late instar larvae roll leaves together with silk to form a 

nest in which they feed. Mature larvae pupate in the leaf rolls or crevices 

in June and adults emerge a few weeks later. Periodic outbreaks of this 

species have occurred in oak forests in North America since the 1960s. 

In Pennsylvania and Michigan, hundreds of thousands of acres have been 

defoliated in some years, with substantial tree mortality and economic 

loss. 

Larvae of oak leafroller feed on a range of oaks (Quercus), especially 

northern red (Quercus rubra L.), scarlet (Q. coccinea Muenchh.), 

chestnut (Q. prinus L.), and white (Q. alba L.) oaks. In addition, this 

moth sometimes feeds on species of witch hazel (Hamamelis) and apple 

(Malus). 

Archips semiferanus is found in southeastern Canada and the eastern 

United States, west to Colorado and Texas.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of 

Oak Leafroller

Figure 1. Adult of oak leafroller, Archips semiferanus. (Todd Gilligan, CSU, 

Bugwood.org)
474 Forest Pest Insects in North America:

Images of Oak

Leafroller (continued)

Figure 2. Larva of oak leafroller. (A. Steven Munson, USDA Forest Service, 

Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

Natural enemies of this species have been studied in Pennsylvania where 

pupae were attacked by two ichneumonids, Itoplectis conquistor (Say) 

and Phaeogenes gilvilabris Allen, and larvae were attacked by various 

tachinids. Larval parasitism was more common than pupal parasitism.

http://en.wikipedia.org/wiki/Archips_semiferanus; Wikipedia fact sheet 

on biology and taxonomy of species.

Freeman, T.N. 1958. The Archipinae of North America. The Canadian 

Entomologist, Supplement No. 7: 89 p.

Chapman, P.J. and S.E. Lienk. 1971. Tortricid fauna of apple in New 

York; including an account of apples’ occurrence in the State, especially 

as a naturalized plant. New York State Agricultural Experiment Station, 

Special Publication, Geneva, New York: 142 p.

Wilson, L.F. 1972. Life history and outbreaks of an oak leafroller, 

Archips semiferanus (Lepidoptera: Tortricidae), in Michigan. Great 

Lakes Entomologist 5: 71-77.

Mumma, R.O. and A.S. Zettle. 1977. Larval and pupal parasites of the 

oak leafroller, Archips semiferanus. Environmental Entomology 6: 

601-605.

Web Links for Information 

on Oak Leafroller

Articles
A Photographic Guide 475

130. Longleaf Pine Seedworm, Cydia ingens (Heinrich) (Lepidoptera: 

Tortricidae)

Orientation to Pest Longleaf pine seedworm, Cydia ingens (Heinrich), is a native tortricid 

that is part of the C. toreuta complex whose members cannot be 

separated morphologically and whose species status is uncertain 

(Gilligan et al. 2008). Species are currently recognized based on host 

and range. C. ingens (in the narrow sense) has been interpreted as being 

restricted to Florida. This species, or closely related forms, occur in the 

southeastern United States where their larvae feed in immature cones of 

long leaf pine (Pinus palustris Mill.), destroying the seeds. 

There are many seed cone worms associated with various pines. In the 

southern United States this species, or a closely related one, feeds on 

long leaf pine (P. palustris).

This species complex is found in the southeastern United States, with 

C. ingens (in the narrow sense) perhaps being restricted to Florida. 

Hosts Commonly Attacked

Distribution

Image of Longleaf

Pine Seedworm

Figure 1. Adult of longleaf pine seedworm, Cydia ingens. (Todd Gilligan, CSU, 

Bugwood.org)

No information is available on natural enemies of this species.

http://www.tortricidae.com/identificationPhoto.asp?NAV=10; website of 

tortricd.net, resources on the Tortricidae.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Longleaf Pine Seedworm
476 Forest Pest Insects in North America:

Articles on

Longleaf Pine Seedworm

Abrahamson, L.P. and K.J. Kraft. 1965. A population study of the cone 

moth Laspeyresia toreuta Grote in Pinus banksiana stands. Ecology

46: 561-563.

Harbo, J.R. and K.J. Kraft. 1969. A study of Phanerotoma toreutae,

a parasite of the pine cone moth Laspeyresia toreuta. Annals of the 

Entomological Society of America 62: 214-220.

Gilligan, T.M., D.J. Wright, and L.D. Gibson. 2008. Olethreutine 

Moths of the Midwestern United States, An Identification Guide.

Ohio Biological Survey 16(2): 334 p. 
A Photographic Guide 477

131. European Pine Shoot Moth, Rhyacionia buoliana (Denis and 

Schiffermiiller) (Lepidoptera: Tortricidae)

Orientation to Pest European pine shoot moth, Rhyacionia buoliana (Denis and 

Schiffermiiller), is an invasive tortricid native to Europe, the eastern 

Mediterranean region, and Japan. It is invasive in the United States, 

Canada, Chile, and Uruguay. It is a serious pest of pines, especially 

in pine plantations because it kills the leaders of pines, destroying 

their growing form. Larvae feed on pines, especially red pine (Pinus 

resinosa Sol. ex Aiton) or introduced European pines, and, in Southern 

Hemisphere plantations, on Monterrey pines (P. radiata D. Don). Buds 

of branches are also attacked. Moths emerge in early summer and lay 

their eggs on new needles. Young larvae construct webs that are coated 

with resin below the current year’s needle sheaths and stems. Feeding 

initially occurs within the sheath at the base of needles. By midsummer, 

larvae switch and feed on buds until August. Larvae overwinter in webs 

at the bases of buds and in spring move to undamaged buds or new 

shoots, where they complete development. Pupation takes place during 

the second summer in the dead buds and shoots, and when adults emerge, 

empty pupal cases remain sticking out of the pupal chambers in the 

hollowed-out buds. One generation occurs each year. Death of leaders 

leads to deformed, bushy trees. In Chile, as much as a third of trees in 

Monterrey pine plantations may be infested.

In North America, this moth attacks various native pines, especially 

red pine (P. resinosa), as well as several introduced European species, 

particularly Mugo (P. mugo Turra) and Scots (P. sylvestris L.) pines. The 

five-needle pines are relatively resistant. In the Southern Hemisphere, an 

important host is the North American species P. radiata, when grown in 

plantations. 

In North America, the moth occurs in southern Canada from 

Newfoundland to the Great Lakes and in the United States south to 

Maryland and Illinois. A separate infestation exists in British Columbia, 

Oregon, and Washington.

Hosts Commonly Attacked

Distribution

Images of European 

Pine Shoot Moth

Figure 1. Adults of European pine shoot moth, Rhyacionia buoliana. (Left: USDA 

Forest Service - Northeastern Area Archive, USDA Forest Service, Bugwood.org; 

right: USDA Forest Service - Ogden Archive, USDA Forest Service, Bugwood.org)
478 Forest Pest Insects in North America:

Images of European 

Pine Shoot Moth 

(continued)

Figure 2. Eggs (right) and first instar larva (left) of European pine shoot moth. 

(USDA Forest Service - Ogden Archive, USDA Forest Service, Bugwood.org)

Figure 3. Larva of European pine shoot moth feeding in shoot. (Fabio Stergulc, 

Università di Udine, Bugwood.org)
A Photographic Guide 479

Images of European 

Pine Shoot Moth 

(continued)

Figure 4. Live pupa 

of European pine 

shoot moth in place in 

damaged shoot (top); 

pupa dissected from 

shoot (middle), and 

cast pupal skin (bottom) 

from damaged leader. 

(Top: David McComb, 

USDA Forest Service, 

Bugwood.org; middle 

and bottom: USDA 

Forest Service - Ogden 

Archive, USDA Forest 

Service, Bugwood.org)
480 Forest Pest Insects in North America:

Images of European 

Pine Shoot Moth 

(continued)

Figure 5. Deformation of 

shape of pine tree; top, 

in young tree; bottom, 

eventual tree shape 

(here, “Y”) due to leader 

death from feeding of 

European pine shoot 

moth. (Top: Jan Liska, 

Forestry and Game 

Management Research 

Institute, Bugwood.org; 

bottom: Fabio Stergulc, 

Università di Udine, 

Bugwood.org)
A Photographic Guide 481

Important Biological Control 

Agents Related to this 

Pest Species

Many studies have described the parasitoids that can be reared from 

larvae and pupae of European pine shoot moth in various countries 

(United States, Canada, Chile, parts of Europe) and on various tree 

species. More than a hundred species of parasitoids have been recorded. 

Studies conducted in coastal areas of Germany in the 1950s and 1960s, 

for example, found larval and pupal parasitism of this species to be 

in the 28-65 percent range in pine plantations. The most common 

parasitoids observed were the ichneumonid Cremastus confluens Grav. 

and the braconid Orgilus obscurator Nees. Similar studies have been 

done in various locations, with some variation in the parasitoid guild. 

Several European parasitoid species were released in North America 

for suppression of this pest, but only a few have become established. 

Of these, only O. obscurator appears to be widespread and of some 

importance. Releases of European parasitoids in North America have, 

however, had limited effect on densities of this pest in most areas. 

Possible explanations for this lack of control may include low vegetation 

diversity in North American pine plantations and a possible need 

to import additional species of parasitoids from Europe. Parasitoid 

importations against this species have also been undertaken in Chile.

http://www.forestry.ubc.ca/fetch21/FRST308/lab4/rhyacionia_buoliana/

europe.html; fact sheet of the University of British Columbia.

http://wiki.bugwood.org/Archive:Northeast/Rhyacionia_buoliana; 

fact sheet of BugwoodWiki, covering biology. 

http://www.pfc.forestry.ca/diseases/nursery/pests/europea1_e.html; 

Natural Resources Canada fact sheet.

http://www.cabi.org/isc/?compid=5&dsid=23641&loadmodule=

datasheet&page=481&site=144; fact sheet of CABI from the UK, 

showing worldwide distribution.

Schultz, A., D. Häussler, K.H. Apel, and E.K. Groll. 1997. RHYASIM - a model illustrating the population dynamics of the pine 

shoot moth (Rhyacionia buoliana). Beiträge für Forstwirtschaft und 

Landschaftsökologie 31(2): 88-91. (In German).

Daterman, G., A. Eglitis, D. Czokajlo, C. Sack, and P. Kirsch. 2001. 

Attract and kill technology for management of European pine shoot 

moth (Rhyacionia buoliana) and Western pine shoot borer (Eucosma 

sonomana). In: Knízek, M., B. Forster, and W. Grodzki (eds.). 

Methodology of forest insect and disease survey in central Europe. 

Proceedings of the Fourth Workshop of the IUFRO Working Party. 

Prague, Czech Republic, 17-20 September 2001. Journal of Forest 

Science 47 (Special Issue 2): 66-69. 

Huerta, A., F. Robredo, J. Diez, and J.A. Pajares. 2006. The parasitoid 

complex selection of the European pine shoot moth (Rhyacionia 

buoliana Den. et Schiff.) (Lepidoptera: Tortricidae) for the biological 

control in Chile. Boletín de Sanidad Vegetal, Plagas 32(4): 95-607. 

(In Spanish). 

Web Links for Information on

European Pine Shoot Moth

Articles
482 Forest Pest Insects in North America:

132. Nantucket Pine Tip Moth, Rhyacionia frustrana (Comstock) 

(Lepidoptera: Tortricidae)

Orientation to Pest Nantucket pine tip moth, Rhyacionia frustrana (Comstock), is a native 

shoot-boring tortricid associated with pines in the eastern United 

States. There is a similar insect, found in Nebraska attacking pines in 

plantations, that was formerly thought to be a subspecies of R. frustrana

but later was recognized as its own species, R. bushnelli Miller. Larvae of 

Nantucket pine tip moth bore into and kill leaders of pines, both reducing 

overall growth in wood volume and deforming the tree. The species is 

a pest of various southern pines in plantations. Some species such as 

shortleaf (Pinus echinata Miller) and loblolly (P. taeda L.) pines are 

severely affected. The proportion of tips infested by this pest decreases 

after trees reach 3-4 meters in height.

In North America, Nantucket pine tip moth attacks several southern pines 

in plantations, especially shortleaf (P. echinata) and loblolly (P. taeda) 

pines. In New England, pitch pine (P. rigida Miller) is a favorite host in 

pine barrens. 

Nantucket pine tip moth occurs in the United States from eastern Texas 

north to Missouri, east to Florida and north to Massachusetts. There is 

also an isolated, invasive population in southern California.

Hosts Commonly Attacked

Distribution

Images of Nantucket

Pine Tip Moth

Figure 1. Adult of Nantucket pine tip moth, Rhyacionia frustrana. (USDA Forest 

Service Archive, USDA Forest Service, Bugwood.org)
A Photographic Guide 483

Images of Nantucket

Pine Tip Moth (continued)

Figure 2. Egg of 

Nantucket pine tip 

moth. (Darrell Ross, 

Oregon State University, 

Bugwood.org)

Figure 3. Larva of 

Nantucket pine tip 

moth. (Darrell Ross, 

Oregon State University, 

Bugwood.org)
484 Forest Pest Insects in North America:

Images of Nantucket

Pine Tip Moth (continued)

Figure 4. Pupa of 

Nantucket pine tip 

moth. (Darrell Ross, 

Oregon State University, 

Bugwood.org)

Figure 5. Dead tips 

caused by feeding 

of Nantucket pine tip 

moth. (Top: Eric R. Day, 

Virginia Polytechnic 

Institute and State 

University, 

Bugwood.org; bottom: 

Darrell Ross, Oregon 

State University, 

Bugwood.org)
A Photographic Guide 485

Images of Nantucket

Pine Tip Moth (continued)

Figure 6. Stunting 

seedling tree due to tip 

death from Nantucket 

pine tip moth feeding. 

(Darrell Ross, Oregon 

State University, 

Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

Many studies have described the parasitoids that can be reared from 

larvae and pupae of Nantucket pine tip moth. Of the various larval 

parasitoids noted, the species that are consistently of greatest importance 

in nearly all studies have been, in order of importance, the ichneumonid 

Campoplex frustranae Cushman, the tachinid Lixophaga mediocris

Aldrich, and the eurytomid Eurytoma pini Bugbee (see Van Driesche 

et al. 1996 for details on natural enemies of this moth). Introduction of 

C. frustranae to California greatly reduced the density of the invasive 

population of this species found in that area.

http://edis.ifas.ufl.edu/in581; a fact sheet of the University of Florida on 

biology and control.

http://na.fs.fed.us/spfo/pubs/fidls/nantucket/nantucket.htm; USDA Forest 

Service leaflet on biology and control.

Web Links for Information 

on Nantucket Pine Tip Moth
486 Forest Pest Insects in North America:

Van Driesche, R.G., S. Healy, and R.C. Reardon. 1996. Biological 

Control of Arthropod Pests of the Northeastern and North Central 

Forests in the United States: A review and recommendations. FHTET 

96-19, December 1996, USDA Forest Service, Morgantown, WV 

(see http://www.forestpestbiocontrol.info/fact_sheets/documents/

arthropodpestsnortheastern_northcentral.pdf).

McCravy, K.W. and C.W. Berisford. 2001. Effects of vegetation control 

on parasitoids of the Nantucket pine tip moth, Rhyacionia frustrana

(Lepidoptera: Tortricidae). Florida Entomologist 84: 282-287.

DeBarr, G.L., J.W. Brewer, R.S. Cameron, and C.W. Berisford. 2002. 

Nantucket pine tip moth, Rhyacionia frustrana, lures and traps: 

what is the optimum combination? The Nantucket pine tip moth: old 

problems, new research. Proceedings of an Informal Conference, The 

Entomological Society of America, Annual Meeting, Atlanta, Georgia, 

USA, 12-16 December 1999. In: Berisford, C.W. and D.M. Grosman 

(eds.). General Technical Report SRS-51, Southern Research Station, 

USDA Forest Service, Ashville, North Carolina: 56-68. 

Articles on Nantucket

Pine Tip Moth
A Photographic Guide 487

133. Pitch Pine Tip Moth, Rhyacionia rigidana (Fernald) (Lepidoptera: 

Tortricidae)

Orientation to Pest Pitch pine tip moth, Rhyacionia rigidana (Fernald), is a member of 

a group of very similar moths, and it resembles Nantucket pine tip 

moth, R. frustrana (Fernald), in appearance and biology. But unlike R. 

frustrana, this moth can attack and kill large pitch pines (Pinus rigida

Mill.). Besides pitch pines, this native North American tortricid attacks 

several other native or introduced pines. The feeding of pitch pine tip 

moth larvae kills branches or leaders, and may kill the entire tree. There 

are three generations per year in the southern United States, but only one 

in the north.

In North America, this moth attacks several native or exotic pines, 

including pitch (P. rigida), Corsican (P. nigra J. F. Arnold), Virginia (P. 

virginiana Mill.), red (P. resinosa Sol. ex Aiton), Scotch (P. sylvestris L.), 

loblolly (P. taeda L.), and slash (P. elliottii Engelm.) pines. 

This moth is found from Georgia to Texas, north to Missouri, New York, 

and Maine.

Hosts Commonly Attacked

Distribution

Image of 

Pitch Pine Tip Moth

Figure 1. Adult of pitch pine tip moth, Rhyacionia rigidana. (Jim Vargo)
488 Forest Pest Insects in North America:

Little to no information is available on the natural enemies of this 

species, apart from some parasitoids reported from this species in 

Missouri (Kearby and Taylor, 1975).

None

Berisford, C.W. 1974. Species isolation mechanisms in Rhyacionia 

frustrana and R. rigidana. Annals of the Entomological Society of 

America 67: 292-294.

Kearby, W.H. and B. Taylor. 1975. Larval and pupal parasites reared 

from tip moths of the genus Rhyacionia in Missouri (Lepidoptera: 

Olethreutidae). Journal of the Kansas Entomological Society 48: 

206-211.

Gargiullo, P.M. and C.W. Berisford 1983. Life tables for the Nantucket 

pine tip moth, Rhyacionia frustrana (Comstock), and the pitch pine 

tip moth, Rhyacionia rigidana (Fernald) (Lepidoptera: Tortricidae). 

Environmental Entomology 12: 1391-1402. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Pitch Pine Tip Moth

Articles
A Photographic Guide 489

134. Southwestern Pine Tip Moth, Rhyacionia neomexicana (Dyar) 

(Lepidoptera: Tortricidae)

The southwestern pine tip moth, Rhyacionia neomexicana (Dyar), is a 

native North American tip moth that distorts and kills terminals of young 

ponderosa pine (Pinus ponderosa Douglas ex Lawson) in Arizona, New 

Mexico, Colorado, the Dakotas, and Nebraska. Moths fly in spring laying 

eggs as new needles emerge. Eggs hatch in 2-3 weeks, and small larvae 

feed inside needles. Later, larvae feed inside needle sheaths or buds and 

eventually the large larvae hollow out growing shoots. Larval feeding 

under the bark of new shoots produces girdling wounds that cause shoots 

to turn brown and become crooked. Mature larvae leave the tips during 

summer and spin cocoons, usually in the bark crevices on the base of 

the tree below the litter, where they pupate and overwinter. There is 

one generation per year. Heavy infestation for consecutive years may 

retard growth, leaving trees short and bushy. Trees are affected in both 

plantations and natural forests. Injury is most severe where trees are 

planted on poor sites. 

In North America, this moth attacks ponderosa (P. ponderosa), Austrian 

(P. nigra J. F. Arnold), Mugo (P. mugo Turra), Scots (P. sylvestris L.), 

and foxtail (P. balfouriana Balf.) pines.

This moth occurs in the United States in Arizona, New Mexico, Utah, 

Colorado, the Dakotas, Montana, and Nebraska.

Hosts Commonly Attacked

Distribution

Image of Southwestern

Pine Tip Moth

Figure 1. Adult of southwestern pine tip moth, Rhyacionia neomexicana. 

(Jim Vargo)

Orientation to Pest
490 Forest Pest Insects in North America:

Little to no information is available on the natural enemies of this 

species.

http://wiki.bugwood.org/HPIPM:Rhyacionia_neomexicana; Bugwood 

Wiki fact sheet on biology and control.

http://www.ext.colostate.edu/pubs/insect/05529.html; Colorado State 

University fact sheet, which compares this species to related tip moths.

http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fsbdev2_026053.pdf; 

USDA Forest Service pest leaflet that includes a distribution map for 

the species.

Jennings, D.T. 1975. Life history and habits of the southwestern pine 

tip moth, Rhyacionia neomexicana (Dyar) (Lepidoptera: Olethreutidae). 

Annals of the Entomological Society of America 68: 597-606.

Stevens, R.E. and D.T. Jennings. 1977. Western pine-shoot borer: a threat 

to intensive management of ponderosa pine in the Rocky Mountain area 

and Southwest. USDA Forest Service, General Technical Report, Rocky 

Mountain Forest and Range Experiment Station, RM-45.

Wagner, M.R. and Z. Chen. 2004. Long-term benefits to the growth 

of ponderosa pines from controlling southwestern pine tip moth 

(Lepidoptera: Tortricidae) and weeds. Journal of Economic Entomology

97: 1972-1977.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information on

Southwestern Pine Tip Moth 

Articles
A Photographic Guide 491

135. Eastern Pine Shoot Borer, Eucosma gloriola Heinrich (Lepidoptera: 

Tortricidae)

Eastern shoot borer, Eucosma gloriola Heinrich, is a tortricid moth, 

native to North America, whose larvae attack shoots of various native 

or introduced pines. Larvae tunnel in new shoots, killing them. The 

shape of the tree’s main trunk becomes deformed when the terminal 

leader is killed. This moth is more common in plantations and artificially 

reforested areas than in native forests. In plantations, 7-41 percent of 

shoots and up to 10 percent of terminal leaders may be infested. 

In North America, this moth attacks various native or introduced pines, 

including eastern white (Pinus strobus L.), jack (P. banksiana Lamb.), 

red (P. resinosa Sol. ex Aiton), Austrian (P. nigra J. F. Arnold), mugo 

(P. mugo Turra), and Scots (P. sylvestris L.) pines.

In North America, this moth is found from the northeastern United States 

west to the Great Lakes states, as well as in southern Canada.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of Eastern

Pine Shoot Borer

Figure 1. Adult of 

eastern pine shoot 

borer, Eucosma gloriola. 

(Tom Murray)

Figure 2. Larva of 

eastern pine shoot 

borer. (Louis Wilson, 

USDA Forest Service)

Figure 3. Exit hole in 

leader of mature larvae 

of eastern pine shoot 

borer. (Louis Wilson, 

USDA Forest Service)
492 Forest Pest Insects in North America:

Images of Eastern Pine

Shoot Borer (continued)

Figure 4. Dead leader (seen as short stub at base of top whorl of branches) 

caused by eastern pine shoot borer. (A. Steven Munson, USDA Forest Service, 

Bugwood.org)

Figure 5. Deformity 

of main trunk of pine 

caused by eastern pine 

shoot borer. (Minnesota 

Department of Natural 

Resources Archive, 

Minnesota Department 

of Natural Resources, 

Bugwood.org)
A Photographic Guide 493

Five species of natural enemies of this borer have been recorded in 

surveys in Pennsylvania, New York, Ontario, and Manitoba: Glypta

sp., Rhorus sp. (both ichneumonids), Bracon rhyacioniae (Muesebeck) 

(Braconidae), Elachertus cidariae Ashmead (Eulophidae), and 

Habrocytus sp. (Pteromalidae). Of these, Glypta sp. (perhaps Glypta 

eucosmae Walley and Baron) may be the most important. Why this 

insect, which causes little damage in forests, becomes damaging in 

plantations is not understood. 

http://www.na.fs.fed.us/spfo/pubs/fidls/eps_borer/eps_borer.htm; USDA 

Forest Service, Forest Insect and Disease Leaflet 134, covering biology 

and control. 

http://ento.psu.edu/extension/christmas-trees/information/pest-factsheets/eastern-pine-shoot-borer-eucosma-gloriola-heinric; fact sheet of 

Pennsylvania State University of biology and control.

Drooz, A.T. 1960. White pine shoot borer (Eucosma gloriola Heinrich). 

Journal of Economic Entomology 53: 248-251. 

Newman, J.H. 1968. First records of the white pine shoot borer, 

Eucosma gloriola (Lepidoptera: Olethreutidae), in Michigan. Michigan 

Entomologist 1: 267-270. 

Wong, H.R. and A.E. Campbell. 1967. The larval feeding habits of the 

eastern pine-shoot borer, Eucosma gloriola Heinrich (Lepidoptera: 

Tortricidae), in jack pine regeneration in Michigan. Manitoba 

Entomologist 1: 42-46.

DeBoo, R.F., W.L. Sippell, and H.R. Wong. 1971. The eastern pine-shoot 

borer, Eucosma gloriola (Lepidoptera: Tortricidae), in North America. 

The Canadian Entomologist 103: 1473-1486. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Eastern Pine Shoot Borer 

Articles
494 Forest Pest Insects in North America:

136. Lodgepole Cone Moth, Eucosma rescissoriana Heinrich (Lepidoptera: 

Tortricidae)

The lodgepole cone moth, Eucosma rescissoriana Heinrich, is found 

in northwestern North America south to central California. It is highly 

destructive to cones and seeds of western white pine (Pinus monticola

Douglas). In British Columbia, adults emerge in May, and oviposition 

occurs in early June; in Idaho, oviposition is in June. Eggs are laid under 

scale tips of second-year cones. Larvae burrow in cones of host plants, 

consuming the seeds. Pupae overwinter, presumably, in the duff. There is 

one generation per year. While a pest in seed orchards in North America, 

it is considered to be a potential biological control agent of P. monticola

in New Zealand, where this pine is invasive outside of plantations.

In North America, this moth attacks western white pine (P. monticola). 

This moth occurs in North America from British Columbia and western 

Alberta south as far as central California and New Mexico.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of 

Lodgepole Cone Moth

Figure 1. Adult of lodgepole cone moth, Eucosma rescissoriana. (Ward Strong, 

BC Ministry of Forests, Bugwood.org)

Figure 2. Eggs of 

lodgepole cone moth 

on cone scale. (Ward 

Strong, BC Ministry of 

Forests, Bugwood.org)
A Photographic Guide 495

Images of Lodgepole 

Cone Moth (continued)

Figure 3. Larvae of lodgepole cone moth hatching from eggs on cone scale. 

(Ward Strong, BC Ministry of Forests, Bugwood.org)

Figure 4. Larvae of lodgepole cone moth inside cone. (Ward Strong, BC Ministry 

of Forests, Bugwood.org)

Figure 5. Appearance of 

early stage of damage 

to cone of western white 

pine by lodgepole cone 

moth. (Ward Strong, 

BC Ministry of Forests, 

Bugwood.org)
496 Forest Pest Insects in North America:

Images of Lodgepole 

Cone Moth (continued)

Figure 6. Internal 

feeding and damage 

to cone of western 

white pine caused by 

lodgepole cone moth. 

(Ward Strong, BC 

Ministry of Forests, 

Bugwood.org)

Twelve species of parasitic insects were found to be associated with E. 

rescissoriana in western white pine cones in northern Idaho, of which the 

three most abundant species were Pimplopterus n. sp. (Ichneumonidae), 

Chelonus petrovae McComb (Braconidae), and Apanteles starki Mason 

(Braconidae). Total parasitism ranged from 9.4 to 40.9 percent in a seedproduction area over three years.

None

Ollieu, M.M. and J.A. Schenk. 1966. The biology of Eucosma 

rescissoriana Heinrich in western white pine in Idaho (Lepidoptera: 

Olethreutidae). The Canadian Entomologist 98: 268-274.

Goyer, R.A. and J.A. Schenk. 1969. Parasitism of the cone moth 

Eucosma rescissoriana (Lepidoptera: Olethreutidae) in northern Idaho. 

The Canadian Entomologist 101: 1063-1069.

Brockerfoff, E.G. and M. Kay. 1998. Prospects and risks of biological 

control of wilding Pinus contorta in New Zealand. Proceedings of the 

51st New Zealand Plant Protection Conference: 216-223. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Lodgepole Cone Moth

Articles
A Photographic Guide 497

137. Western Pine Shoot Borer, Eucosma sonomana Kearfott (Lepidoptera: 

Tortricidae)

Orientation to Pest The western pine shoot borer, Eucosma sonomana Kearfott, is a 

significant pest of ponderosa (Pinus ponderosa Douglas ex C. Lawson) 

and lodgepole (P. contorta Douglas ex Louden) pines in many parts of 

the western North America, and is especially damaging to young, opengrown trees. Larvae bore in terminal shoots, feeding exclusively in 

the pith. As a result, they stunt the growth but rarely kill the terminals. 

Larvae leave shoots in late spring, drop to the ground, and pupate. 

Repeated attacks lead to shorter trees and may cause up to a 20 percent 

loss in volume growth over a rotation.

In North America, this moth attacks ponderosa (P. ponderosa) and 

lodgepole (P. contorta) pines.

In North America, this moth occurs is recorded from Arizona, New 

Mexico, Wyoming, Colorado, Utah, South Dakota, Montana, Idaho, 

California, Oregon, Washington, and British Columbia (see map in 

Sartwell et al., 1980).

Hosts Commonly Attacked

Distribution

Images of Western

Pine Shoot Borer

Figure 1. Adult of 

western pine shoot 

borer, Eucosma 

sonomana. 

(Scott Tunnock, 

USDA Forest Service, 

Bugwood.org)

Figure 2. Larva of 

western pine shoot borer 

in leader. (Darrell Ross, 

Oregon State University, 

Bugwood.org)
498 Forest Pest Insects in North America:

Images of Western

Pine Shoot Borer

(continued)

Figure 3. Tunnels of western pine shoot borer in lodgepole pine. (Left: USDA 

Forest Service - Ogden Archive, USDA Forest Service, Bugwood.org; right: 

Darrell Ross, Oregon State University, Bugwood.org)

Figure 4. Terminal 

of pine damaged by 

western pine shoot 

moth. (Darrell Ross, 

Oregon State University, 

Bugwood.org)
A Photographic Guide 499

No information was available on natural enemies of this species.

None

Stevens, R.E. and D.T. Jennings. 1977. Western pine shoot borer: A 

threat to intensive management of ponderosa pine in the Rocky Mountain 

area and southwest. USDA Forest Service, Rocky Mountain Forest and 

Range Experiment Station, Fort Collins, Colorado, General Technical 

Report RM-45: 8 p.

Sartwell, C., G.E. Daterman, T.W. Koerber, R.E. Stevens, and L.L. 

Sower. 1980. Distribution and hosts of Eucosoma sonomana in the 

western United States as determined by trapping with synthetic sex 

attractants. Annals of the Entomological Society of America 73: 254-256.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Western Pine Shoot Borer

Articles
500 Forest Pest Insects in North America:

138. Douglas-fir Cone Moth, Barbara colfaxiana (Kearfott) (Lepidoptera: 

Tortricidae)

Orientation to Pest The Douglas-fir cone moth, Barbara colfaxiana (Kearfott), is found 

in western North America from California to British Columbia, east to 

Montana, and Colorado. Adults emerge in the spring and lay their eggs 

on young cones. Young larvae feed largely on cone scales, but older 

larvae consume developing seeds. Pupae overwinter in papery, resincoated cocoons in center of cones. Pupae may remain in diapause for as 

long as 3 years. Damage occurs on Douglas-fir (Pseudotsuga menziesii

[Mirb.] Franco) and true firs (Abies) and is greatest at inland (noncoastal) sites, where summers are hotter and drier. One larva can destroy 

60 percent of the seeds in a cone, while three larvae will likely destroy 

all of the seeds. There is one generation per year. Pheromone traps using 

the pheromone of Contarinia oregonensis Foote, can be used to monitor 

the pest. 

In North America, this moth attacks Douglas-fir (P. menziesii) and 

various true firs (Abies).

In North America, this moth occurs is recorded from California to British 

Columbia, east to Montana, and Colorado.

Hosts Commonly Attacked

Distribution

Images of 

Douglas-fir Cone Moth

Figure 1. Adults of 

Douglas-fir cone moth, 

Barbara colfaxiana. 

(D. Manastyrski, 

Bugwood.org)

Figure 2. Larva of 

Douglas-fir cone moth. 

(Julie Brooks, 

Bugwood.org)
A Photographic Guide 501

Images of Douglas-fir 

Cone Moth (continued)

Figure 3. Pupa of 

Douglas-fir cone moth. 

(D. Manastyrski, 

Bugwood.org)

Figure 4. Douglas-fir 

cone moth, Barbara 

colfaxiana, caught 

in trap baited with 

pheromone of Contarinia 

oregonensis. 

(Ward Strong, 

BC Ministry of Forests, 

Bugwood.org)

The ichneumonid Glypta evetriae Cushman is reported as a parasitoid of 

this species. 

http://www.forestry.ubc.ca/fetch21/FRST308/lab2/barbara_colfaxiana/

conemoth.html; fact sheet of the University of British Columbia.

http://www.fgcouncil.bc.ca/PM-Factsheet08-Barbara-colfaxiana.pdf; 

fact sheet on control of Douglas-fir cone moth.

Clark, E.C., J.A. Schenk, and D.L. Williamson. 1963. The cone-infesting 

moth Barbara colfaxiana as a pest of Douglas-fir in northern Idaho. 

Annals of the Entomological Society of America 56: 246-250.

Hedlin, A.F. 1974. Cone and seed insects of British Columbia. Canadian 

Forestry Service, Pacific Forestry Research Centre, Victoria, BC. 

BC-X-90: 63 p.

Nebeker, T.E. 1977. A partial life table for the Douglas-fir cone moth, 

Barbara colfaxiana (Lepidoptera: Olethreutidae). The Canadian 

Entomologist 109: 943-951. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Douglas-fir Cone Moth

Articles
502 Forest Pest Insects in North America:

Sweeney, J.D. and G.E. Miller. 1989. Distribution of Barbara colfaxiana

(Kearfott) (Lepidoptera: Tortricidae) eggs within and among Douglasfir crowns and methods for estimating egg densities. The Canadian 

Entomologist 121: 569-578.

Koerber, T.W. and G.P. Markin. 1984. Metasystox-R® injections increase 

seed yield of Douglas-fir in California, Oregon, and Washington. 

In: Yates, H.O., III (ed.). Proceedings of the Cone and Seed Insects 

Working Party Conference. Asheville, North Carolina, Southeastern 

Forest Experiment Station: 137-146. 

Articles on Douglas-fir 

Cone Moth (continued)
A Photographic Guide 503

139. Pine Webworm, Pococera robustella (Zeller) (Lepidoptera: Pyralidae)

Pine webworm, Pococera robustella (Zeller), is a native North American 

moth. Females lay groups of one to 10 overlapping eggs on host needles. 

Young larvae are pine needle miners, but older larvae feed externally, 

building webs around groups of needles. Larvae leave the nest to 

clip needles, which they bring back into the nest to consume. Mature 

larvae move to the ground and spin cocoons in which they pupate. 

Several species of pines are attacked. In southern slash pine (Pinus 

elliottii Engleman) plantations, damage occurs mainly in the first year 

after planting. In northern parts of the United States, damage occurs 

in jack (P. banksiana Lamb.) and red pine (P. resinosa Sol. ex Aiton) 

plantations, but is mostly of concern to Christmas tree growers due to 

the unsightliness of the webs. There are one (in the north) to three (in the 

south) generations per year. 

In North America, this moth attacks many pine species but is most 

common on slash (P. elliottii), red (P. resinosa) and jack (P. banksiana) 

pines.

This moth occurs in southern Canada and throughout most of the eastern 

United States. 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of 

Pine Webworm

Figure 1. Adult 

pine webworm, 

Pococera robustella. 

(Natasha Wright, 

Florida Department 

of Agriculture and 

Consumer Services, 

Bugwood.org

Figure 2. Larva of pine 

webworm. (Connecticut 

Agricultural Experiment 

Station Archive, 

Connecticut Agricultural 

Experiment Station, 

Bugwood.org)

Pine webworm
504 Forest Pest Insects in North America:

Images of Pine

Webworm (continued)

Figure 3. Feeding 

web of larvae of pine 

webworm. 

(Robert L. Anderson, 

USDA Forest Service, 

Bugwood.org)

Figure 4. Damage to 

a young pine seedling 

caused by pine 

webworm. 

(Robert L. Anderson, 

USDA Forest Service, 

Bugwood.org)
A Photographic Guide 505

Important Biological Control 

Agents Related to this 

Pest Species

The ichneumonid Syzeuctus elegans (Cresson) is a common parasitoid 

of this species. Other natural enemies include other parasitic wasps, 

parasitic flies, predatory insects and birds. 

http://entnemdept.ufl.edu/creatures/trees/moths/pine_webworm.htm; 

fact sheet of the University of Florida, covering biology and control.

http://wiki.bugwood.org/Pococera_robustella; fact sheet of Bugwood 

wiki covering biology and control.

http://www.freshfromflorida.com/pi/enpp/ento/entcirc/ent419.pdf; 

fact sheet of Florida Department of Agriculture and Consumer Services, 

Division of Plant Industry.

Hertel, G.D. and D.M. Benjamin. 1979. Biology of the pine webworm 

in Florida slash pine plantations. Annals of the Entomological Society of 

America 72: 816-819. 

Wallesz, D.P. and D.M. Benjamin. 1960. The biology of the pine 

webworm, Tetralopha robustella, in Wisconsin. Journal of Economic 

Entomology 53: 587-589.

Web Links for Information 

on Pine Webworm

Articles
506 Forest Pest Insects in North America:

140. Zimmerman Pine Moth, Dioryctria zimmermani (Grote) (Lepidoptera: 

Pyralidae)

Zimmerman pine moth, Dioryctria zimmermani (Grote), is one member 

of a group of closely related native North American species that have 

been poorly distinguished and still await further clarification in some 

cases. Names in the older literature may be unreliable. Adults of D. 

zimmermani emerge in mid-summer and lay their eggs in various places 

on the tree trunk or buds. Upon hatching, larvae immediately settle into 

bark crevices and overwinter in hibernacula. Larvae resume feeding the 

following spring by tunneling into newly formed terminals or lateral 

shoots, which become hooked and discolored. Larvae feed on the 

cambial layer and outer xylem of all common pine species. Feeding sites 

are distinguished by large masses of accumulated frass and pitch. When 

mature, larvae leave the terminals and tunnel into the whorl, girdling tips 

or branches. Pupation takes place in the pitch masses associated with 

larval feeding. 

In North America, this moth attacks most common pines, but damage 

is principally important in Christmas tree plantations of Scotch (Pinus 

syvestris L.), red (P. resinosa Sol. ex Aiton), and Austrian (P. nigra J. F. 

Arnold) pines in the north central United States and southeastern Canada.

In North America, this moth occurs in southeastern Canada and the 

northeastern United States, as far west as Minnesota.

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of 

Zimmerman Pine Moth

Figure 1. Adult of Zimmerman pine moth, Dioryctria zimmermani. (Whitney 

Cranshaw, Colorado State University, Bugwood.org)
A Photographic Guide 507

Images of Zimmerman 

Pine Moth (continued)

Figure 2. Larva of 

Zimmerman pine 

moth. (Phil Pellitteri, 

University of Wisconsin, 

Entomology Dept, 

Bugwood.org)

Figure 3. Feeding of Zimmerman pine moth larvae results in pitch accumulations 

on the bark, usually near the branch nodes. (Left: Rayanne Lehman, 

Pennsylvania Department of Agriculture, Bugwood.org; right: Whitney Cranshaw, 

Colorado State University, Bugwood.org)

Figure 4. Pupal skin of Zimmerman pine moth inside pitch mass (opened). 

(Phil Pellitteri, University of Wisconsin, Entomology Dept, Bugwood.org)
508 Forest Pest Insects in North America:

Various parasitoids are listed in the literature as attacking this species. 

But many of these studies predate the clarification of species boundaries 

in this group and so it is unclear exactly which species these records refer 

to. Regardless, total parasitism in most studies did not exceed 5 percent. 

http://greenindustry.uwex.edu/problemdetails.cfm?problemid=99; 

fact sheet of the University of Wisconsin on recognition and control.

http://ento.psu.edu/extension/christmas-trees/information/pest-factsheets/zimmerman-pine-moth; fact sheet of Pennsylvania State 

University on biology and control.

http://extension.psu.edu/ipm/program/christmas-tree/pest-fact-sheets/

stem-and-root-injury/zimmerman.pdf; fact sheet of Pennsylvania State 

University on biology and control.

Yonker, J.W. and D.L. Schuder. 1980. The biology of the Zimmerman 

pine moth (Dioryctria zimmermani) in Indiana landscapes with reference 

to its control. Proceedings of the Indiana Academy of Science 89: 

207-208.

Mutuura, A. 1982. American species of Dioryctria (Lepidoptera: 

Pyralidae). VI. A new species of Dioryctria from eastern Canada 

and north-eastern United States. The Canadian Entomologist 114: 

1069-1076.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Zimmerman Pine Moth

Articles
A Photographic Guide 509

141. Fall Cankerworm, Alsophila pometaria (Harris) (Lepidoptera: 

Geometridae)

Orientation to Pest Fall cankerworm, Alsophila pometaria (Harris), is a native moth capable 

of defoliating many hardwood species. The species overwinters as 

eggs, which hatch in early spring to coincide with bud break. Young 

“inchworm” larvae skeletonize new leaves, while older larvae consume 

all but the larger veins or midrib. By midsummer, mature larvae crawl 

down or drop on silk threads to the soil where they pupate in the soil. 

Adults emerge in early winter (November or early December) after initial 

frosts to mate. The wingless females climb tree trunks and deposit their 

eggs in rows in a single layer on smaller branches or trunk. There is one 

generation per year. In some areas fall cankerworm periodically goes into 

outbreak, causing widespread damage. Damage results from complete or 

partial defoliation of forest or urban trees. 

In North America, larvae of this defoliating moth attack a wide range 

of hardwoods and shrubs, including elm (Ulmus), maple (Acer), ash 

(Fraxinus), oak (Quercus), apple (Malus domestica Borkh.), hickory 

(Carya tomentosa [Poir.] Nutt.), dogwood (Cornus), and many others. 

This moth has a wide distribution in southeastern Canada and the eastern 

United States, west to Alberta, Montana, and Missouri, and south to 

North Carolina.

Hosts Commonly Attacked

Distribution

Images of 

Fall Cankerworm

Figure 1. Adults of fall 

cankerworm, Alsophila 

pometaria; top, wingless 

female; bottom, male. 

(Top: James B. Hanson, 

USDA Forest Service, 

Bugwood.org; bottom: 

USDA Forest Service 

- Region 8 - Southern 

Archive, USDA Forest 

Service, Bugwood.org)
510 Forest Pest Insects in North America:

Images of Fall 

Cankerworm (continued)

Figure 2. Egg mass of fall cankerworm. Note straight rows of eggs in single layer. 

(Pennsylvania Department of Conservation and Natural Resources - Forestry 

Archive, Bugwood.org)

Figure 3. Larvae of fall 

cankerworm; top, young 

larva; bottom, mature 

larvae. (Top: A. Steven 

Munson, USDA Forest 

Service, Bugwood.org; 

bottom: E. Bradford 

Walker, Vermont 

Department of Forests, 

Parks and Recreation, 

Bugwood.org)
A Photographic Guide 511

Images of Fall 

Cankerworm (continued)

Figure 4. Feeding of fall cankerworm. (USDA Forest Service - Ogden Archive, 

USDA Forest Service, Bugwood.org)

Figure 5. Defoliation 

of hardwoods by fall 

cankerworms. (James B. 

Hanson, USDA Forest 

Service, Bugwood.org)

Figure 6. Sticky bands 

on shade trees to 

trap fall cankerworm 

females. (G. Keith 

Douce, University of 

Georgia, Bugwood.org)

Fall cankerworm
512 Forest Pest Insects in North America:

Relatively few parasitoids have been recorded attacking this species. 

Among these are the braconid Meteorus autographae Muesbeck and 

the scelionid egg parasitoid Telenomus alsophilae Viereck. The latter is 

believed to be the most important parasitoid affecting this species, killing 

15-20 percent of the eggs. A nuclear polyhedrosis virus is also associated 

with this species and some strains of Bacillus thuringiensis Berliner are 

effective against it. 

http://ento.psu.edu/extension/factsheets/fall-cankerworm; fact sheet of 

Pennsylvania State University on biology and control.

http://www.maine.gov/doc/mfs/fallcank.htm; fact sheet of the Maine 

Department of Conservation on biology and control.

http://www.umassgreeninfo.org/fact_sheets/defoliators/cankerworm.

html; Extension fact sheet from the University of Massachusetts.

http://ohioline.osu.edu/hyg-fact/2000/2558.html; Extension fact sheet of 

the Ohio State University comparing spring and fall cankerworms.

Fedde, G.F. 1980. Spring parasitism of fall cankerworm eggs in northern 

Georgia by Telenomus alsophilae (Hymenoptera: Scelionidae). Journal 

of the Georgia Entomological Society 15: 199-206.

Miller, F., K. Malmquist, and G. Ware. 2001. Evaluation of Asian, 

European, and North American elm (Ulmus spp.) biotypes to feeding by 

spring and fall cankerworms. Journal of Environmental Horticulture 19: 

216-221.

LaFrance, K.R. and A.R. Westwood. 2006. An assessment of tree 

banding techniques to capture cankerworm defoliators of elm and ash 

trees in Winnipeg, Manitoba, Canada. Arboriculture and Urban Forestry

32: 10-17. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Fall Cankerworm

Articles
A Photographic Guide 513

142. Spring Cankerworm, Paleacrita vernata (Peck) (Lepidoptera: 

Geometridae)

Orientation to Pest Spring cankerworm, Paleacrita vernata (Peck), is a native North 

American moth that defoliates many hardwood species and in some 

locations goes into periodic outbreaks. Damage is caused by young 

“inchworm” larvae skeletonizing new leaves and older larvae consuming 

all but the larger veins or midrib. This species may be confused with 

the very similar fall cankerworm, Alsophila pometaria (Harris). Adults 

emerge from pupal cells in the soil in early spring when the ground is 

thawed. Females crawl up tree trunks to lay eggs, which are deposited 

in loose clusters of 100 or more in bark crevices or under bark scales. 

Eggs hatch in early spring and larvae feed on leaves through the end of 

spring. Mature larvae drop to the soil on silk threads in summer. Larvae 

remain dormant within their soil-covered pupal cells throughout the rest 

of the summer and fall, pupating in late fall or early spring. There is one 

generation per year. 

In North America, larvae of this moth feed on many hardwood species, 

including elm (Ulmus), green ash (Fraxinus pennsylvanica Marsh.), 

maple (Acer), bur oak (Quercus macrocarpa Michx.), linden/basswood 

(Tilia), silver birch (Betula pendula Roth), and apple (Malus domestica

Borkh.). 

This geometrid is found in southeastern Canada, as well as throughout 

the northeastern and north central United States, and west to parts of 

Texas, Colorado, and California. 

Hosts Commonly Attacked

Distribution

Images of Spring

Cankerworm

Figure 1. Adults of 

spring cankerworm, 

Paleacrita vernata; top, 

wingless female; bottom, 

male. (Top: Mark 

Ascerno, University of 

Minnesota, University of 

Minnesota • Extension; 

bottom: Nolie Schneider, 

Bugwood.org)
514 Forest Pest Insects in North America:

Images of Spring

Cankerworm (continued)

Figure 2. Larvae of 

spring cankerworm. 

(Top: James B. Hanson, 

USDA Forest Service, 

Bugwood.org; bottom: 

USDA Forest Service 

- Northeastern Area 

Archive, USDA Forest 

Service, Bugwood.org)

Figure 3. Tree trunk with band trap to catch female spring cankerworms as they 

crawl up trees. (William A. Carothers, USDA Forest Service, Bugwood.org)
A Photographic Guide 515

Several species of parasitoids are known from spring cankerworm, 

including three braconids, Rogas geometrae Ashmead, Apanteles 

paleacritae Riley, and Meteorus hyphantriae Riley. It is also attacked 

by the ichneumonids Phobcampe geometrae (Ashmead) and Hyposoter 

fuscitarsis (Vierieck). Bacillus thuringiensis Berliner is bacterium that 

has been formulated as a biopesticide that can be used to control larvae 

of this species. 

http://ohioline.osu.edu/hyg-fact/2000/2558.html; Extension fact sheet of 

the Ohio State University comparing spring and fall cankerworms.

http://www.extension.umn.edu/distribution/horticulture/dg0876.html; 

fact sheet of University of Minnesota extension service comparing spring 

and fall cankerworms.

http://insects.tamu.edu/fieldguide/cimg293.html; fact sheet of the Texas 

A&M University on biology and control.

http://entomology.unl.edu/ornamentals/pestprofiles/scankerworm.shtml; 

fact sheet of the University of Nebraska on biology and control. 

Frye, R.D., D.K. McBride, D.R. Carey, T.L. Elichuk, and R.L. Dregseth. 

1977. Cankerworm control in shelterbelts. North Dakota Farm Research

34(6): 3-7.

LaFrance, K.R. and A.R. Westwood. 2006. An assessment of tree 

banding techniques to capture cankerworm defoliators of elm and ash 

trees in Winnipeg, Manitoba, Canada. Arboriculture and Urban Forestry

32: 10-17. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Spring Cankerworm

Articles
516 Forest Pest Insects in North America:

143. Eastern Hemlock Looper, Lambdina fiscellaria fiscellaria Guenée 

(Lepidoptera: Geometridae)

Orientation to Pest Eastern hemlock looper, Lambdina fiscellaria fiscellaria Guenée, is a 

native North American geometrid whose larvae defoliate eastern hemlock 

(Tsuga canadensis [L.] Carrière), balsam fir (Abies balsamea [L.] Mill.) 

and white spruce (Picea glauca [Moench] Voss). It is found in Canada 

from Newfoundland to Alberta and in the United States it occurs widely 

within the range of eastern hemlock. Adults fly in late summer or fall 

and lay eggs singly or in small groups on bark, or associated moss and 

lichens. Winter is spent in the egg stage and larvae begin to feed in the 

late spring on newly opened clusters of needles. Older larvae also feed 

on old needles. Some attacked needles are chewed but not severed and 

remain attached, giving the tree a brown appearance. Pupation usually 

takes place on the bark. Repeated periodic outbreaks have occurred over 

wide areas in eastern Canada and the northeast and north central United 

States, especially Newfoundland, Wisconsin, and Michigan. 

This moth feeds mainly on eastern hemlock (T. canadensis) (especially 

in the more southerly parts of it range) but in the north also feeds on 

balsam fir (A. balsamea) and white spruce (P. glauca). During outbreaks 

it sometimes feeds on other conifers and even some hardwoods. 

This geometrid is found in Canada from Newfoundland to Alberta, and in 

the United States it occurs widely within the range of eastern hemlock.

Hosts Commonly Attacked

Distribution

Images of Eastern

Hemlock Looper

Figure 1. Adult of 

eastern hemlock looper, 

Lambdina fiscellaria 

fiscellaria. (Thérèse 

Arcand - Natural 

Resources Canada, 

Canadian Forest 

Service)

Figure 2. Eggs of 

eastern hemlock looper. 

(Thérèse Arcand 

- Natural Resources 

Canada, Canadian 

Forest Service)
A Photographic Guide 517

Images of Eastern

Hemlock Looper (continued)

Figure 3. Larva of eastern hemlock looper. (Connecticut Agricultural Experiment 

Station Archive, Connecticut Agricultural Experiment Station, Bugwood.org)

Figure 4. Defoliation from eastern hemlock looper in Michigan. (USDA Forest 

Service - Northeastern Area Archive, USDA Forest Service, Bugwood.org)

Because outbreaks occur of this species defoliator, its natural enemies 

have been studied on various occasions. Before 1950, the most common 

parasitoid attacking it was the braconid larval parasitoid Apanteles

sp. nr. flavovariatus Muesbeck. But subsequently a parasitic tachinid, 

Winthemia occidentis Reinhard, associated with another hemlock looper 

in western North America, was introduced and is now the dominant 

parasitoid of eastern hemlock looper. Pupal parasitism, while reaching up 

to 30 percent or more, is due to a collection of polyphagous parasitoids.

Important Biological Control 

Agents Related to this 

Pest Species
518 Forest Pest Insects in North America:

Web Links for Information 

on Eastern Hemlock Looper 

http://imfc.cfl.scf.rncan.gc.ca/insecte-insect-eng.asp?geID=8846; fact 

sheet of Natural Resources Canada on phenology and extent of damage 

in Canada.

http://www.glfc.forestry.ca/VLF/ForumPresentations/

heberthemlocklooper_08e.pdf; detailed history of outbreaks in Canada.

MacLean, D.A. and E. Paul Ebe. 1999. The impact of hemlock looper 

(Lambdina fiscellaria fiscellaria [Guen.]) on balsam fir and spruce in 

New Brunswick, Canada. Forest Ecology and Management 120: 77-87 

Hartling, L.K., N. Carter, and J. Proude. 1999. Spring parasitism of 

overwintered eggs of Lambdina fiscellaria fiscellaria (Lepidoptera: 

Geometridae) by Telenomus near alsophilae (Hymenoptera: Scelionidae). 

The Canadian Entomologist 131: 421-422.

VanFrankenhuyzen, K., R.J. West, and M. Kenis. 2001. Lambdina 

fiscellaria fiscellaria (Guenée), hemlock looper (Lepidoptera: 

Geometridae). In: Mason, P.G. and J.T. Huber (eds.). Biological Control 

Programmes in Canada, 1981-2000. CABI Publishing, Wallingford, UK: 

141-144.

Iqbal, J., D.A. MacLean, and J.A. Kershaw, Jr. 2011. Impacts of hemlock 

looper defoliation on growth and survival of balsam fir, black spruce and 

white birch in Newfoundland, Canada. Forest Ecology and Management

261: 1106-1114.

Articles
A Photographic Guide 519

144. Western Hemlock Looper, Lambdina fiscellaria lugubrosa (Hulst) 

(Lepidoptera: Geometridae)

Orientation to Pest Western hemlock looper, Lambdina fiscellaria lugubrosa (Hulst), is 

a native North American geometrid whose larvae defoliate western 

hemlock (Tsuga heterophylla [Raf.] Sarg.) in coastal areas of Oregon, 

Washington, and British Columbia. Adults fly in late summer or fall 

and lay eggs on bark, or associated moss and lichens or even downed 

logs. Winter is spent in the egg stage and larvae begin to feed in the 

late spring. Young larvae may feed on understory vegetation of various 

kinds of trees or shrubs. Initial feeding on hemlock is concentrated in 

the buds. In summer, older larvae attack old needles, some of which 

are notched but not severed. These remain attached, giving the tree 

a brown appearance. Mature larvae spin silk threads and drop to the 

ground to pupate in the late summer. New moths emerge in fall to lay 

overwintering eggs. Repeated large outbreaks occurred over wide areas 

in western North America in the past, damaging large volumes of old 

growth hemlock. However, since old growth hemlock stands in many 

areas have been logged, outbreaks have become smaller.

This moth feeds mainly on western hemlock (T. heterophylla), but during 

outbreaks other conifer species and hardwood shrubs are also attacked.

This geometrid is found in western North America in coastal forests of 

Oregon, Washington, and British Columbia.

Hosts Commonly Attacked

Distribution

Images of Western

Hemlock Looper

Figure 1. Adult of western hemlock looper, Lambdina fiscellaria lugubrosa. 

(Jerald E. Dewey, USDA Forest Service, Bugwood.org)
520 Forest Pest Insects in North America:

Images of Western

Hemlock Looper 

(continued)

Figure 2. Larva of 

western hemlock looper. 

(Jerald E. Dewey, 

USDA Forest Service, 

Bugwood.org)

Figure 3. Defoliation of a 

western hemlock stand 

by western hemlock 

looper. (Bruce Hostetler, 

USDA Forest Service, 

Bugwood.org)
A Photographic Guide 521

Images of Western

Hemlock Looper 

(continued)

Figure 4. Defoliation of a western hemlock stand by western hemlock looper. 

(USDA Forest Service - Ogden Archive, USDA Forest Service, Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

Pupal parasitoids reported from this species in Alaska included eight 

ichnuemonids: Pimpla pedalis Cresson, P. aquilonia Cresson, P. hesperus

(Townes), Apechthis ontario (Cresson), Itoplectis quadricingulatus

(Prov.), Masttus laplantei Mason, Cratichneumon sp. (probably C. 

ashmeadi [Schulz]), and Aoplus velox occidentalis (Harrington).

http://www.fs.fed.us/r1-r4/spf/fhp/field_guide/109wsthml.htm; 

USDA Forest Service fact sheet on recognition and biology of pest.

http://www.fs.fed.us/r1-r4/spf/fhp/mgt_guide/hemlock_looper/page2.

html; USDA Forest Service fact sheet on recognition and biology of pest.

http://www.fs.fed.us/r1-r4/spf/fhp/mgt_guide/hemlock_looper/index.

html; a USDA Forest Service manual on control of western hemlock 

looper.

http://imfc.cfl.scf.rncan.gc.ca/insecte-insect-eng.asp?geID=1000002; 

a fact sheet of Natural Resources Canada on biology and phenology of 

pest.

http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5191788.

pdf; a USDA Forest Service manual on control and management of 

western hemlock looper.

Torgersen, T.R. 1971. Parasites of the western hemlock looper, Lambdina 

fiscellaria lugubrosa (Hulst), in southeast Alaska (Lepidoptera: 

Geometridae). Pan-Pacific Entomologist 47: 215-219.

Harris, J.W.E., A.F. Dawson, and R.G. Brown. 1982. The western 

hemlock looper in British Columbia 1911-1980. Report BC-X-234, 

Pacific Forest Research Centre, Canada: 18 p.

Mills, N.J. and M. Räther. 1990. Hemlock loopers in Canada; biology, 

pest status and potential for biological control. Biocontrol News and 

Information 11(3): 209-222. 

Articles

Web Links for Information 

on Western Hemlock Looper
522 Forest Pest Insects in North America:

145. Greenstriped Forest Looper, Melanolophia imitata (Walker) 

(Lepidoptera: Geometridae)

Orientation to Pest Greenstriped forest looper, Melanolophia imitata (Walker), is a native 

geometrid found in moist conifer forests of western North America. 

Adults fly in spring and lay eggs singly (up to 80 per female) on tree 

branches and trunks. Larvae feed on foliage of all ages, but the previous 

year’s foliage is preferred and damage is concentrated in tree crowns. 

In late summer larvae drop to the ground and pupate in the litter, where 

they overwinter. There is one generation per year. Larvae are solitary 

feeders and generally are not economically damaging. However, periodic 

outbreaks have occurred in Canada (especially British Columbia) that 

were destructive to western hemlock (Tsuga heterophylla [Raf.] Sarg.). 

Outbreaks in the past have ended abruptly due to natural causes. 

This moth feeds mainly on western hemlock (T. heterophylla), Douglas 

fir (Pseudotsuga menziesii [Mirbel] Franco), western redcedar (Thuja 

plicata Donn ex D. Don), true firs (Abies), and spruce (Picea).

This geometrid is found in western North America from Alaska to 

southern California and, in Canada, eastward to Alberta, in humid areas. 

Hosts Commonly Attacked

Distribution

Images of Greenstriped

Forest Looper

Figure 1. Adult of greenstriped forest looper, Melanolophia imitata. (Marius 

Aurelian, Bugwood.org)
A Photographic Guide 523

Images of Greenstriped

Forest Looper (continued)

Figure 2. Larva of 

greenstriped forest 

looper. (Natural 

Resources Canada, 

Canadian Forest 

Service)

Important Biological Control 

Agents Related to this 

Pest Species

Past studies have shown that fungal pathogens such as species of 

Cordyceps and Entomophthora cause significant mortality to pupae in 

the soil. 

http://imfc.cfl.scf.rncan.gc.ca/insecte-insect-eng.asp?geID=1000022; fact 

sheet of Natural Resources Canada on phenology and biology of insect.

http://www.for.gov.bc.ca/hfp/publications/00198/green_striped_forest_

looper.htm; short fact sheet of the Ministry of Forests and Range, 

Province of British Columbia.

http://cfs.nrcan.gc.ca/pubwarehouse/pdfs/3317.pdf; forest pest leaflet 

on greenstriped forest looper by Pacific Forestry Centre of Natural 

Resources Canada.

Evans, D. 1962. Descriptions and life history of Melanolophia imitata

(Walker) (Lepidoptera: Geometridae). The Canadian Entomologist 94: 

594-605. 

Humphreys, N. 1986. Green-striped forest looper in British Columbia. 

Canadian Forest Service, Pacific Forestry Centre, FIDS Report No. 86-9: 

43 p.

Web Links for Information on

Greenstriped Forest Looper

Articles
524 Forest Pest Insects in North America:

146. Saddleback Looper, Ectropis crepuscularia (Denis and Schiffermüller) 

(Lepidoptera: Geometridae)

Orientation to Pest Saddleback looper, Ectropis crepuscularia (Denis and Schiffermüller), 

is a native North American looper present across southern Canada, the 

adjacent tier of U.S. states, and the eastern United States. This species 

is a generalist, feeding more on conifers in western North American and 

all of Canada, but on various hardwood species in the eastern United 

States. Adults fly in spring, when they lay their eggs. Larvae are solitary 

feeders able to mimic twigs. Young larvae often begin feeding first on 

groundcover species and understory shrubs. Larvae later move up trees 

where they complete development. Mature larvae drop to the soil to 

pupate in the litter, where they overwinter. There at least two generations 

per year over much of the eastern United States. Larvae of this species 

are generally economically damaging. Outbreaks in British Columbia 

and Alaska have occurred. 

In Canada and the western United States, saddleback loopers feed mostly 

commonly on conifers, including hemlock (Tsuga), true firs (Abies), 

spruce (Picea), and larch (Larix). In the eastern United States, broadleaf 

trees are the main hosts, including apple (Malus), ash (Fraxinus), birch 

(Betula), dogwood (Cornus), maple (Acer), oak (Quercus), poplar 

(Populus), walnut (Juglans), and willow (Salix).

This geometrid is found in a band across North America including 

southern Canada and the adjacent tier of U.S. states. In the eastern United 

States, it is also found south to Florida.

Hosts Commonly Attacked

Distribution

Images of 

Saddleback Looper

Figure 1. Adult of saddleback looper, Ectropis crepuscularia. (John Davis, 

Bugwood.org)
A Photographic Guide 525

Images of Saddleback 

Looper (continued)

Figure 2. Larva of saddleback looper. (Connecticut Agricultural Experiment 

Station Archive, Connecticut Agricultural Experiment Station, Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

No information on the natural enemies of this species was found. 

http://imfc.cfl.scf.rncan.gc.ca/insecte-insect-eng.asp?geID=8578; fact 

sheet of Natural Resources Canada on biology and phenology of species.

Ferris, R.L. 1993. Saddleback looper. Forest Pest Leaflet No. 23. Pacific 

Forestry Centre, Canadian Forest Service: 3 p. 

Web Links for Information 

on Saddleback Looper

Articles
526 Forest Pest Insects in North America:

147. Spearmarked Black Moth, Rheumaptera hastata (L.) (Lepidoptera: 

Geometridae)

Orientation to Pest Spearmarked black moth, Rheumaptera hastata (L.), is a native North 

American looper found from North Dakota to British Columbia and 

Alaska. It feeds mainly on birch (Betula). Adults fly in spring. In Alaska, 

eggs are laid singly or in clusters on tops of leaves, from mid-June to 

early July. Young larvae feed gregariously between two leaves webbed 

together to make a sandwich-type shelter. Larvae feed on both new and 

old-growth foliage and usually feed just on the upper side, skeletonizing 

leaves. Larvae mature in July and August, drop to the ground on silken 

threads and pupate in the leaf litter, where they overwinter. There is 

one generation per year. This moth is a serious defoliator of paper birch 

(Betula papyrifera Marsh.) in interior Alaska. Epidemic populations 

have occurred at 15- to 17-year intervals, persisted for 2 years, and then 

collapsed from natural causes.

This species feeds mainly on mainly on birch (Betula spp.). In Alaska, 

paper birch (Betula papyrifera Marsh.) is the preferred host, but larvae 

also feed on species of alder (Alnus), willow (Salix), and rose (Rosa). In 

Canada, the insect also feeds on sweetgale (Myrica).

This geometrid is found throughout Canada 

and Alaska, and the northern United States, 

with southerly range extensions along 

mountain chains (Cascades, Rockies, 

Appalachians).

Hosts Commonly Attacked

Distribution

Figure 1. North American distribution of 

spearmarked black moth, Rheumaptera hastata. 

(USDA Forest Service • Forest Insect & Disease 

Leaflet 156)

Images of Spearmarked

Black Moth

Figure 2. Adult of 

spearmarked black 

moth. (S. Overby 

- Swedish Museum of 

Natural History)
A Photographic Guide 527

Images of Spearmarked

Black Moth (continued)

Figure 3. Life stages 

(adult, eggs, larva, 

pupae) of spearmarked 

black moth. (USDA 

Forest Service • Forest 

Insect & Disease Leaflet 

156)

Figure 4. Larva of 

spearmarked black 

moth. (Graham Finch)

Figure 5. Tent made by 

larva of spearmarked 

black moth, where it 

feeds. (Graham Finch)

Figure 5. Birch 

defoliated by 

spearmarked black 

moth. (Peter A. Rush, 

USDA Forest Service, 

Bugwood.org)
528 Forest Pest Insects in North America:

Parasitoids that have been reared from the overwintering pupae of this 

moth include Aoplus ruficeps vagans Provancher (Ichneumonidae), 

Coccygomimus aquilonius (Ichneumonidae), and Cratichneumon

sp. (Ichneumonidae). The parasitoid Meteorus niveitarsis Cresson 

(Braconidae) has been reared from larvae.

http://www.na.fs.fed.us/spfo/pubs/fidls/spear/spear.htm; USDA Forest 

Service fact sheet on biology and pest status in Alaska.

McGuffin, W.C. 1973. The Rheumaptera of North America (Lepidoptera: 

Geometridae). The Canadian Entomologist 105: 383-389.

Werner, R.A. and B.H. Baker. 1977. Spear-marked black moth. Forest 

Insect & Disease Leaflet 156. Portland, OR. U.S. Dept. of Agriculture, 

Forest Service, Pacific Northwest Forest and Range Experiment Station. 

Available at http://www.ncrs.fs.fed.us/pubs/viewpub.asp?key=965.

Werner, R.A.1977. Biology and behavior of the spear-marked 

black moth, Rheumaptera hastata, in interior Alaska. Annals of the 

Entomological Society of America 70: 328-336.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Spearmarked Black Moth

Articles
A Photographic Guide 529

148. Elm Spanworm, Ennomos subsignarius (Hübner) (Lepidoptera: 

Geometridae)

Orientation to Pest Elm spanworm, Ennomos subsignarius (Hübner), is a native geometrid 

moth whose polyphagous larvae feed on many species of hardwood 

trees, especially hickory (Carya), oak (Quercus), and ash (Fraxinus). It 

is most important as a forest pest in the Appalachian Mountains, from 

Pennsylvania south, but an urban forest outbreak has also occurred in St. 

John’s, Newfoundland, and Labrador. This univoltine species overwinters 

as eggs, which are laid in clusters on the bole and on the underside of 

branches. Eggs hatch in early spring and young larvae feed on the lower 

surfaces of leaves, producing “shot-hole” damage. Older larvae consume 

the whole leaf apart from the major veins. After developing through five 

instars, larvae pupate in loose silk cocoons formed on the partly eaten 

foliage and in bark crevices. Outbreaks of this species occur at irregular 

intervals that defoliate trees over wide areas. 

This species feeds on elm (Ulmus), hickory (Carya), oak (Quercus), 

maple (Acer), beech (Fagus), and ash (Fraxinus).

This geometrid is found in hardwood forests from Newfoundland and 

Labrador to Saskatchewan in Canada and throughout the eastern United 

States, west to Michigan, Colorado, and Texas.

Hosts Commonly Attacked

Distribution

Images of 

Elm Spanworm

Figure 1. Adults of elm spanworm, Ennomos subsignarius, mating (left) and 

laying eggs (right). (Both photos: Heidi Fry, Bugwood.org)
530 Forest Pest Insects in North America:

Images of Elm 

Spanworm (continued)

Figure 2. Egg mass of 

elm spanworm. (Heidi 

Fry, Bugwood.org)

Figure 3. Early (left) and late (right) instar larvae of elm spanworm. (Both photos: 

Heidi Fry, Bugwood.org)

Figure 4. Masses of 

elm spanworm larvae 

feeding on host plant 

during an outbreak. 

(Bugwood.org)

Figure 5. Pupae of elm 

spanworm. (Arnold T. 

Drooz, USDA Forest 

Service, Bugwood.org)
A Photographic Guide 531

Images of Elm 

Spanworm (continued)

Figure 6. Shot hole 

or tattered damage 

from feeding of elm 

spanworms. (Heidi Fry, 

Bugwood.org)

Figure 7. Trees 

defoliated by elm 

spanworm. (Heidi Fry, 

Bugwood.org)

Figure 8. Defoliation 

of a forest stand by 

elm spanworm. 

(William M. Ciesla, 

Forest Health 

Management 

International, 

Bugwood.org)
532 Forest Pest Insects in North America:

Images of Elm 

Spanworm (continued)

Figure 9. Adults of the egg parasitoid Telenomus droozi emerging from eggs of 

elm spanworm. (Arnold T. Drooz, USDA Forest Service, Bugwood.org)

Some of the more important biological control agents affecting this 

species are the egg parasitoid Telenomus droozi Muesebeck and the 

predatory carabid Calosoma scrutator (F.), which eats larvae.

http://ento.psu.edu/extension/factsheets/elm-spanworm; fact sheet of 

Pennsylvania State University on biology and control. 

http://www.fs.fed.us/r8/foresthealth/idotis/insects/elmspan.html; short 

fact sheet of the USDA Forest Service Forest Health Protection Southern 

Region on biology and control.

Anderson, J.F. and K.K. Harry. 1976. Parasitoids and diseases of the elm 

spanworm. Journal of the New York Entomological Society 84: 169-177. 

Drooz, A.T. 1980. A review of the biology of the elm spanworm 

(Lepidoptera: Geometridae). Great Lakes Entomologist 13: 49-53. 

Fry, H.R.C., D.T. Quiring, K.L. Ryall, and P.L. Dixon. 2008. 

Relationships between elm spanworm, Ennomos subsignaria, juvenile 

density and defoliation on mature sycamore maple in an urban 

environment. Forest Ecology and Management 255: 2726-2732.

Fry, H.R.C., K.L. Ryall, P.L. Dixon, and D.T. Quiring. 2008. Suppression 

of Ennomos subsignaria (Lepidoptera: Geometridae) on Acer 

pseudoplatanus (Aceraceae) in an urban forest with bole-implanted 

acephate. Journal of Economic Entomology 101: 822-828.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Elm Spanworm

Articles
A Photographic Guide 533

149. Winter Moth, Operophtera brumata (L.) (Lepidoptera: Geometridae)

Orientation to Pest Winter moth, Operophtera brumata (L.), is a European geometrid that 

is invasive in North America, in Nova Scotia, part of British Colombia, 

and, most recently, southern New England. It is a defoliator that is 

a generalist feeder, attacking a variety of hardwoods. Winter moths 

overwinter as eggs, which hatch early in spring, and young larvae feed 

on opening buds and developing leaves. Older larvae feed inside loose 

leaf rolls and, when mature, drop to the ground, where they pupate late 

May to early June. Adults emerge in late fall or early winter. Females, 

which are wingless, climb trees to lay eggs. Persistent defoliation leads 

to branch death, top kill, and tree death. 

This species is a generalist feeder that attacks are variety of hardwoods, 

but especially apple (Malus), red oak (Quercus rubra L.), American elm 

(Ulmus americana L.), red maple (Acer rubrum L.), American basswood 

(Tilia americana L.), and hop hornbeam (Ostrya virginiana [Mill.] K. 

Koch).

This geometrid is native in Europe, but in North America invasive 

populations exist in Nova Scotia, the Pacific Northwest (Oregon 

to British Columbia) and the northeastern United States. Outbreak 

populations currently exist in eastern Massachusetts and Rhode Island. 

A survey with pheromone traps by Elkinton et al. (2010) recovered 

winter moths mainly in coastal areas from Long Island to Maine. 

Hosts Commonly Attacked

Distribution

Images of 

Winter Moth

Figure 1. Adults of winter 

moth, Operophtera 

brumata; male (top) 

and wingless female 

(bottom). (Top: LouisMichel Nageleisen, 

Département de la 

Santé des Forêts, 

Bugwood.org; bottom: 

Gyorgy Csoka, Hungary 

Forest Research 

Institute, Bugwood.org)
534 Forest Pest Insects in North America:

Images of Winter

Moth (continued)

Figure 2. Eggs of 

winter moth. (Gyorgy 

Csoka, Hungary Forest 

Research Institute, 

Bugwood.org)

Figure 3. Larvae of 

winter moth. (Both 

photos: Milan Zubrik, 

Forest Research 

Institute - Slovakia, 

Bugwood.org)

Figure 4. Pupa of winter 

moth. (Hannes Lemme, 

Bugwood.org)
A Photographic Guide 535

Images of Winter

Moth (continued)

Figure 5. Feeding of larvae of winter moth. (Hannes Lemme, Bugwood.org)

This species has well known natural enemies, having been studied in part 

of its native range (the UK) and been the target of successful classical 

biological control programs in both eastern and western Canada. Similar 

work is now underway in Massachusetts. The natural enemies of most 

importance are the tachinid parasitoid, Cyzenis albicans Fallén, and the 

ichneumonid Argypon flaveolatum (Gravenhorst). The tachinid is the 

more important. 

http://www.umassgreeninfo.org/fact_sheets/defoliators/wm_overview_

09.pdf; University of Massachusetts fact sheet. 

http://en.wikipedia.org/wiki/Winter_Moth; Wikipedia article.

http://www.youtube.com/watch?v=kVxzOl8zrUE; Youtube video 

on Cyzinis albicans releases in Massachusetts by Joe Elkinton of the 

University of Massachusetts.

Ring, R.A. 1988. Pest management of the European winter moth, 

Operophtera brumata (L.), in British Columbia. Northwest 

Environmental Journal 41: 329-330.

Embree, D.G. 1991.The winter moth Operophtera brumata in eastern 

Canada, 1962-1988. Forest Ecology and Management 39: 47-54.

Elkinton, J.S., G.H. Boettner, M. Sremac, R. Gwiazowski, R. Hunkins, 

J. Callahan, S.B. Schuefele, C. Donahue, A.H. Porter, A. Khrimian, B.M. 

Whited, and N.K. Campbell. 2010. Survey for winter moth (Lepidoptera: 

Geometridae) in northeastern North America with pheromone-baited 

traps and hybridization with the native Bruce spanworm. Annals of the 

Entomological Society of America 103: 135-145.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Winter Moth

Articles
536 Forest Pest Insects in North America:

150. Bruce Spanworm, Operophtera bruceata (Hulst) (Lepidoptera: 

Geometridae)

Orientation to Pest Bruce spanworm, Operophtera bruceata (Hulst), is a native geometrid 

moth in North America that closely resembles winter moth (Operophtera 

brumata [L.]). It is found from coast to coast in Canada and from New 

England to the Lake States in the United States. Bruce spanworm is 

a defoliator and a generalist feeder, attacking a variety of hardwoods. 

Bruce spanworm overwinters as eggs, which hatch early in spring. 

Larvae either feed openly or in the shelter of leaves that are loosely 

rolled and webbed together. When mature, larvae drop to the ground, 

where they pupate. Adults emerge in fall. Females, which are wingless, 

climb trees to lay eggs in bark crevices or under loose bark. Defoliating 

outbreaks have been reported. 

This species is a generalist feeder that attacks are variety of hardwoods, 

but especially sugar maple (Acer saccharum Marshall), trembling aspen 

(Populus tremuloides Michx.), willow (Salix), and American beech 

(Fagus grandifolia Ehrh.), among others. 

This geometrid is found from coast to coast in Canada and from New 

England to the Lake states in the United States.

Hosts Commonly Attacked

Distribution

Images of 

Bruce Spanworm

Figure 1. Adults of bruce spanworm, Operophtera bruceata; male (left) and 

wingless female (right). (Left: Ronald S. Kelley, Vermont Department of Forests, 

Parks and Recreation, Bugwood.org; right: Pennsylvania Department of 

Conservation and Natural Resources - Forestry Archive, Bugwood.org)
A Photographic Guide 537

Images of Bruce 

Spanworm (continued)

 Figure 2. Egg of bruce 

spanworm. (Ronald 

S. Kelley, Vermont 

Department of Forests, 

Parks and Recreation, 

Bugwood.org)

Figure 3. Larvae of 

bruce spanworm. 

(E. Bradford Walker, 

Vermont Department 

of Forests, Parks 

and Recreation, 

Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

The natural enemies of this species are less well known than are those of 

the closely related winter moth. 

http://www.maine.gov/doc/mfs/brucspan.htm; fact sheet of the state 

of Maine.

Elkinton, J.S., G.H. Boettner, M. Sremac, R. Gwiazdowski, 

R.R. Hunkins, J. Callahan, S.B. Scheufele, C.P. Donahue, A.H. Porter, 

A. Khrimian, B.M. Whited, and N.K. Campbell. 2010. Survey for 

winter moth (Lepidoptera: Geometridae) in northeastern North America 

with pheromone-baited traps and hybridization with the native Bruce 

spanworm (Lepidoptera: Geometridae). Annals of the Entomological 

Society of America 103: 135-145.

Web Links for Information 

on Bruce Spanworm

Articles
538 Forest Pest Insects in North America:

151. Forest Tent Caterpillar, Malacosoma disstria Hübner (Lepidoptera: 

Lasiocampidae)

Orientation to Pest Forest tent caterpillar, Malacosoma disstria Hübner, occurs throughout 

Canada and the United States and is a generalist defoliator that feeds on 

a variety of hardwood trees. In the north and west of the United States 

(and southern Canada), trembling aspen (Populus tremuloides Michx.) 

is preferred. In the southern United States, various gums (Nyssa spp. 

and Liquidambar styraciflua L.) and oaks (Quercus) are the common 

hosts. However, during outbreaks, larvae will feed on a wide variety 

of hardwood species. Winter is passed as eggs, which hatch in spring. 

Larvae begin feeding on buds and expanding leaves. Older larvae feed 

on mature leaves. Young larvae feed in groups, but older larvae are 

dispersed. Larvae lay silk trails, which they follow, but they do not form 

a silken tent. Rather, they make silk mats on which larvae rest. Mature 

larvae wander and pupate inside a yellowish-white cocoon fixed to 

the host tree or other objects. Adults emerge in midsummer (north) or 

spring (south) and lay their eggs in clusters that encircle twigs of the 

host tree. Eggs are cemented together and covered with dark colored 

material called spumaline. There is one generation per year. A number 

of very large outbreaks, covering thousands of square miles and lasting 

for several years, have occurred in North America. Tree mortality is 

generally low, but loss of growth can be considerable (>70 percent) due 

to effects of defoliation. In the southern United States, in bottomlands, 

gum trees may die from defoliation. In the northeastern United States, 

defoliation of sugar maple stands lowers maple syrup yields and quality. 

This species is a generalist defoliator that feeds on a variety of hardwood 

trees. In the north and west, trembling aspen (P. tremuloides) is preferred. 

In the southern United States, gums (Nyssa spp. and L. styraciflua) and 

oaks (Quercus) are common hosts. 

Forest tent caterpillar occurs throughout Canada and the United States.

Hosts Commonly Attacked

Distribution

Images of Forest

Tent Caterpillar

Figure 1. Adult of 

forest tent caterpillar, 

Malacosoma disstria. 

(Whitney Cranshaw, 

Colorado State 

University, 

Bugwood.org)
A Photographic Guide 539

Images of Forest

Tent Caterpillar

(continued)

Figure 2. Eggs of forest 

tent caterpillar (top) 

and newly hatched 

caterpillars on egg mass 

(bottom). (Top: Steven 

Katovich, USDA Forest 

Service, Bugwood.org; 

bottom: E. Bradford 

Walker, Vermont 

Department of Forests, 

Parks and Recreation, 

Bugwood.org)

Figure 3. Larvae of forest tent caterpillar feeding. (Gerald J. Lenhard, Louiana 

State University, Bugwood.org)
540 Forest Pest Insects in North America:

Images of Forest

Tent Caterpillar

(continued)

Figure 4. Larvae of 

forest tent caterpillar 

resting together on 

trunk. (Andrew J. Boone, 

South Carolina 

Forestry Commission, 

Bugwood.org

Figure 5. Forest tent 

caterpillar cocoon (with 

pupa inside). (James B. 

Hanson, USDA Forest 

Service, Bugwood.org)
A Photographic Guide 541

Images of Forest

Tent Caterpillar

(continued)

Figure 6. Interior view of stand defoliated by forest tent caterpillar. (Herbert A. 

‘Joe’ Pase III, Texas Forest Service, Bugwood.org)

Figure 7. Strips of water tupelo (Nyssa aquatica L.) defoliated by forest tent 

caterpillar (green areas are strips of less favored host species). (William M. Ciesla, 

Forest Health Management International, Bugwood.org)

The natural enemies of this species are well known and include 

14 species of Hymenoptera egg parasites and, attacking larvae or pupae, 

52 Diptera, and 61 Hymenoptera species. In addition there are some 

18 Hemiptera, nine Coleoptera, and one Dermaptera that are predators of 

various life stages of forest tent caterpillar. In northern areas, the tachinid 

Sarcophaga aldrichi Park is important in terminating outbreaks. In the 

northeastern United States, the tachinids Zenilla protuberans A and W 

and Compsilura concinnata Meigan are also important.

Important Biological Control 

Agents Related to this 

Pest Species
542 Forest Pest Insects in North America:

Web Links for Information 

on Forest Tent Caterpillar

http://facultyweb.cortland.edu/fitzgerald/ForestTentCaterpillar.html; 

website of T.D. Fitzgerald. “Social Caterpillars: Forest Tent Caterpillar 

(Malacosoma disstria).”

http://na.fs.fed.us/spfo/pubs/fidls/ftc/tentcat.htm; Forest and Disease Pest 

Leaflet No. 9 of the USDA Forest Service.

http://entnemdept.ufl.edu/creatures/trees/forest_tent_caterpillar.htm; 

fact sheet of the University of Florida on biology and control. 

http://www.youtube.com/watch?v=x81ba8-e_O8--Youtube; video of 

forest tent caterpillars moving about.

Witter, J.A. and H.M. Kuhlman. 1972. A review of the parasites and 

predators of tent caterpillars (Malacosoma spp.) in North America. 

Minnesota Agricultural Experiment Station. Technical Bulletin 289: 48 p.

Parry, D., J.R. Spence, and W.J.A. Volney. 1997. Responses of natural 

enemies to experimentally increased populations of forest tent caterpillar, 

Malacosoma disstria. Ecological Entomology 22: 97-108.

Wood, D.M., D. Parry, R.D. Yanai, and N.E. Pitel. 2010. Forest 

fragmentation and duration of forest tent caterpillar (Malacosoma 

disstria Hübner) outbreaks in northern hardwood forests. Forest Ecology 

and Management 260: 1193-1197.

Wood, D., R. Yanai, D. Allen, and S. Wilmot. 2009. Sugar maple decline 

after defoliation by forest tent caterpillar. Journal of Forestry 107: 29-37. 

Articles
A Photographic Guide 543

152. Eastern Tent Caterpillar, Malacosoma americanum (F.) (Lepidoptera: 

Lasiocampidae)

Orientation to Pest Eastern tent caterpillar, Malacosoma americanum (F.), occurs throughout 

southern Canada and the eastern United States and is a defoliator that 

feeds on a variety of hardwood trees, especially cherry (Prunus) and 

apple (Malus). Winter is passed as eggs, which hatch in spring. Larvae 

begin feeding on buds and expanding leaves. Older larvae feed on mature 

leaves. Larvae lay silk trails that they follow to foliage, where they feed 

in groups. When not feeding, larvae shelter in silk tents constructed 

low in trees in the forks of branches. Mature larvae wander and pupate 

inside a yellowish-white cocoon fixed to the host tree or other objects. 

Adults emerge in midsummer (north) or spring (south) and lay their 

eggs in clusters that encircle twigs of the host trees. Eggs are cemented 

together and covered with dark colored material called spumaline. There 

is one generation per year. This species is primarily a nuisance species, 

causing little economic loss, with the exception of black cherry (Prunus 

serotina Ehrh.) stands managed to produce veneer wood. The tents of this 

species are commonly seen along roadsides on young cherry or apple. 

Caterpillars that have fed on cherry, if then eaten by horses, can cause 

mares to abort, making this pest of special concern in areas dedicated to 

rearing race horses.

This species is a generalist defoliator on a variety of hardwood trees, 

especially cherry (Prunus) and apple (Malus). 

This species occurs throughout southern Canada and the eastern United 

States.

Hosts Commonly Attacked

Distribution

Images of Eastern

Tent Caterpillar

Figure 1. Adult of 

eastern tent caterpillar, 

Malacosoma 

americanum. 

(Lacy L. Hyche, 

Auburn University, 

Bugwood.org)
544 Forest Pest Insects in North America:

Images of Eastern Tent

Caterpillar (continued)

Figure 2. Egg masses of eastern tent caterpillar. (A. Steven Munson, USDA 

Forest Service, Bugwood.org)

Figure 3. Young larvae of forest tent caterpillar on a small web. (A. Steven 

Munson, USDA Forest Service, Bugwood.org)
A Photographic Guide 545

Images of Eastern Tent

Caterpillar (continued)

Figure 4. Large larvae of eastern tent caterpillar. (Joseph O’Brien, USDA Forest 

Service, Bugwood.org)

Figure 5. Close up of eastern tent caterpillar larva. (Clemson University - USDA

Cooperative Extension Slide Series, Bugwood.org)
546 Forest Pest Insects in North America:

Images of Eastern Tent

Caterpillar (continued)

Figure 6. Comparison 

of caterpillars of eastern 

tent caterpillar (right) 

and forest tent caterpillar 

(left). (Ronald S. Kelley, 

Vermont Department 

of Forests, Parks 

and Recreation, 

Bugwood.org)

Figure 7. Close up of 

eastern tent caterpillar 

tent with mature larvae. 

(William H. Hoffard, 

USDA Forest Service, 

Bugwood.org)
A Photographic Guide 547

Images of Eastern Tent

Caterpillar (continued)

Figure 8. Eastern tent caterpillar cocoon (with pupa inside). (Lacy L. Hyche, 

Auburn University, Bugwood.org)

Figure 9. Webs of eastern tent caterpillar on defoliated trees. (Left: Robert L. 

Anderson, USDA Forest Service, Bugwood.org; right: G. Keith Douce, University 

of Georgia, Bugwood.org)
548 Forest Pest Insects in North America:

Important Biological Control 

Agents Related to this 

Pest Species

A variety of natural enemies of this species have been recognized. See 

Van Driesche et al. (2002) for details. However, their importance in 

determining the density of this species has not been investigated. 

http://www.ca.uky.edu/entomology/entfacts/ef423.asp; fact sheet of the 

University of Kentucky on biology and control.

http://ohioline.osu.edu/hyg-fact/2000/2022.html; fact sheet of Ohio State 

University.

http://www.ag.auburn.edu/enpl/bulletins/easterntentcaterpillar/

easterntentcaterpillar.htm; fact sheet of Auburn University, Alabama.

http://www.youtube.com/watch?v=1qO6eCygcTE; a time lapse video of 

web construction and feeding on Youtube.

http://www.dec.ny.gov/animals/7111.html; New York Department of 

Conservation site comparing gypsy moths and eastern tent caterpillar.

Progar, R.A., M.J. Rinella, D. Fekedulegn, and L. Butler. 2010. Nuclear 

polyhedrosis virus as a biological control agent for Malacosoma 

americanum (Lepidoptera: Lasiocampidae). Journal of Applied 

Entomology 134: 641-646.

Haynes, K.F., J. McLaughlin, S. Stamper, C. Rucker, F.X. Webster, 

D. Czokajlo, and P. Kirsch. 2007. Pheromone trap for the eastern tent 

caterpillar moth. Environmental Entomology 36: 1199-1205.

Crump, D., R.M. Silverstein, H.J. Williams, and T.D. Fitzgerald. 1987. 

Identification of trail pheromone of larva of eastern tent caterpillar 

Malacosoma americanum (Lepidoptera: Lasiocampidae). Journal of 

Chemical Ecology 13: 397-402.

VanDriesche, R.G., S. Healy, and R.C. Reardon. 2002. Biological 

Control of Arthropod Pests of the Northeastern and North Central 

Forests in the United States. A review and recommendations. FHTET96-19. USDA Forest Service, Morgantown, West Virginia. (Available at 

http://www.fs.fed.us/foresthealth/technology/pdfs/FHTET_96_19.pdf).

Web Links for Information 

on Eastern Tent Caterpillar

Articles
A Photographic Guide 549

153. Siberian Moth, Dendrolimus sibiricus TschetvericKov (Lepidoptera: 

Lasiocampidae)

Orientation to Pest Siberian moth, Dendrolimus sibiricus TschetveriKov, is a defoliator 

of great importance in northern Asia, causing widespread, extensive 

mortality to various conifers during outbreaks. It does not occur in North 

American but is a species of great concern. Typically, this moth has a 

two-year life cycle, spread over parts of three calendar years. Adults 

fly and lay eggs from late June to mid-July. Eggs are laid in chains or 

clusters on needles or branches. In their first year, larvae feed until they 

reach the second or third instar and then overwinter in the forest litter. In 

year two, partly grown larvae continue to feed, at a slower rate, until they 

are in the fifth to seventh instar, at which stage they overwinter. In their 

third calendar year, larva feed until mature in spring and pupate inside 

cocoons fixed to trees. Adult moths appear in late June and July and 

may fly several kilometers before laying eggs. Outbreaks occur at about 

10 year intervals and last 2-3 years. An outbreak can defoliate thousands 

of hectares and affect entire forests. Since the insect has overlapping 

generations and life cycles extending more than one growing season, it 

can defoliate stands in the spring, summer and fall, but most defoliation 

occurs in spring when older larvae feed. 

Larvae of D. sibiricus feed on the foliage of more than 20 species of 

conifers in northern Asia, especially on species of larch (Larix) and fir 

(Abies), but also on less favored hosts such as five-needle and two-needle 

pines (Pinus) and spruce (Picea). Injury is greatest to species of fir and 

certain pines (e.g., P. koraiensis Sieb. et Zucc. and P. sibirica Du Tour). 

Although larch species are the most favored hosts, they can re-foliate and 

are seldom killed. It has been shown that this polyphagous species can 

develop on a wide range of European and North American conifers.

The Siberian moth does not occur in North America, but is considered 

a very high risk invader because of its potential for invasion and the 

magnitude of likely damage. Boreal and subalpine forests in North 

America would be at risk. Its current distribution includes Siberia 

(Russia), northeastern China, northern Mongolia, and part of North 

Korea.

Hosts Commonly Attacked

Distribution
550 Forest Pest Insects in North America:

Images of 

Siberian Moth

Figure 1. Male Siberian moth, Dendrolimus sibericus. (Natalia Kirichenko, 

Bugwood.org)

Figure 2. Egg mass of Siberian moth. (John H. Ghent, USDA Forest Service, 

Bugwood.org)

Figure 3. Larva of 

Siberian moth. (John 

H. Ghent, USDA Forest 

Service, Bugwood.org)
A Photographic Guide 551

Images of Siberian 

Moth (continued)

Figure 4. Pupal cocoons of Siberian moth. (John H. Ghent, USDA Forest Service, 

Bugwood.org)

Figure 5. Stand of Siberian larch (Larix sibirica Ledeb.) defoliated by Siberian 

moth. (John H. Ghent, USDA Forest Service, Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

More than 40 species of parasitoids are known to attack D. sibiricus, of 

which the most important are the egg parasites Telenomus tetratomus

(Thomson) (Scelionidae) and Ooencyrtus pinicola Matsumura 

(Encyrtidae), the larval parasite Rogas dendrolimi Matsumura 

(Braconidae), and the larval-pupal parasites Blepharipa schineri

(Mesnil.), Blepharipa pratensis Meigen, and Lespesia frenchii

(Williston) (all Tachinidae). 
552 Forest Pest Insects in North America:

Web Links for Information 

on Siberian Moth

http://www.aphis.usda.gov/plant_health/plant_pest_info/pest_detection/

downloads/pra/dsuperanspra.pdf; a mini risk assessment of Siberian silk 

moth (from a North American perspective).

http://www.eppo.org/QUARANTINE/insects/Dendrolimus_sibiricus/

DS_Dendrolimus_spp.pdf; an EPPO data sheet for European quarantine 

officials.

http://www.issg.org/database/species/ecology.asp?si=1428&fr=1&sts=&l

ang=EN; write up on species in Global Invasive Species Database.

ftp://ftp.fao.org/docrep/fao/011/i0640e/i0640e10h.pdf; fact sheet by 

United Nations FAO group.

http://spfnic.fs.fed.us/exfor/data/pestreports.cfm?pestidval=45&langdispl

ay=english; Exotic forest pest data sheet of the USDA Forest Service.

Kirichenko, N.I., J. Flament, Y.N. Baranchikov, and J.-C. Grégoire. 2008. 

Native and exotic coniferous species in Europe – possible host plants for 

the potentially invasive Siberian moth, Dendrolimus sibiricus Tschtv. 

(Lepidoptera, Lasiocampidae). OEPP/EPPO Bulletin 38: 259-263.

Kirichenko, N.I., Y.N. Baranchikov, and S. Vidal. 2009. Performance of 

the potentially invasive Siberian moth Dendrolimus superans sibiricus

on coniferous species in Europe. Agricultural and Forest Entomology

11: 247-254. 

Articles
A Photographic Guide 553

154. Pinkstriped Oakworm, Anisota virginiensis (Drury) (Lepidoptera: 

Saturniidae)

Pinkstriped oakworm, Anisota virginiensis (Drury), is a native moth 

that feeds on foliage of oaks (Quercus) and other hardwoods. It occurs 

throughout the eastern United States and southern Canada. Young larvae 

feed in groups, skeltonizing leaves. Older larvae are less gregarious and 

consume all but the main veins of leaves. Larvae can be found April 

through September depending on the climate, with one generation per 

year in its northern range and up to three generations per year in its 

southern-most range. This insect is common but not abundant and is 

usually considered a minor pest to landscape trees where damage to 

larger trees is often limited to defoliation of single branches. However, 

small trees can be completely defoliated.

Pinkstriped oakworm feeds primarily on oaks (Quercus), but it is also 

reported from chestnut (Castanea), hazel (Corylus), maple (Acer), and 

birch (Betula). 

This species occurs in southern Canada and the eastern United States, as 

far west as Manitoba and Texas. 

Orientation to Pest

Hosts Commonly Attacked

Distribution

Images of 

Pinkstriped Oakworm

Figure 1. Adults of pinkstriped oakworm, Anisota virginiensis: male and female 

mating. (Pennsylvania Department of Conservation and Natural Resources 

- Forestry Archive, Bugwood.org)
554 Forest Pest Insects in North America:

Images of Pinkstriped 

Oakworm (continued)

Figure 2. Eggs of pinkstriped oakworm. (James Solomon, USDA Forest Service, 

Bugwood.org)

Figure 3. Young larvae of pinkstriped oakworm. (Lacy L. Hyche, Auburn 

University, Bugwood.org)

Figure 4. Close up of pinkstriped oakworm larva. (James Solomon, USDA Forest 

Service, Bugwood.org)
A Photographic Guide 555

Images of Pinkstriped 

Oakworm (continued)

Figure 5. Pupa of pinkstriped oakworm. (Lacy L. Hyche, Auburn University, 

Bugwood.org)

Figure 6. A group of pinkstriped oakworm caterpillars defoliating an oak branch. 

(James Solomon, USDA Forest Service, Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

In Manitoba, five species of larval or pupal parasitoids have been 

recorded from this species: Houghia sternalis (Coquillett), Lespesia 

anisotae Webber, and Winthemia datanae (Tns.) (all Tachinidae); and 

Habronyx magniceps (Cresson) and Hyposoter fugitivus (Say) (both 

Ichneumonidae).
556 Forest Pest Insects in North America:

Web Links for Information 

on Pinkstriped Oakworm

http://www.ag.auburn.edu/enpl/bulletins/pinkoakworm/pinkoakworm.

htm; fact sheet of Auburn University on recognition and biology.

http://okeechobee.ifas.ufl.edu/News%20columns/

Pinkstriped%20Oakworm.htm; University of Florida fact sheet on 

biology and control.

http://www.fs.fed.us/r8/foresthealth/idotis/insects/oakworm.html; USDA 

Forest Service fact sheet on two oakworm species.

Wagner, D.L., V. Giles, R.C. Reardon, and M.L. McManus. 1998. 

Caterpillars of Eastern Forests. USFS Technology Transfer Bulletin, 

FHTET-96-34: 113 p. 

Henne, D.C. 2004. Parasitoid survey of Anisota virginiensis

(Lepidoptera: Saturniidae) at Belair, Manitoba from 1989-1999. 

Proceedings of the Entomological Society of Manitoba 60: 5-10. 

Articles
A Photographic Guide 557

155. Orangestriped Oakworm, Anisota senatoria (J.E. Smith) (Lepidoptera: 

Saturniidae)

Orientation to Pest Orangestriped oakworm, Anisota senatoria (J.E. Smith), is a native 

silkmoth that feeds mainly on the foliage of oaks (Quercus). It has as a 

wide distribution in eastern United States and southern Canada. Adults 

appear in the June or July in the northern part of its range and lay groups 

of eggs on the undersides of leaves of host trees. Young larvae feed in 

groups, skeletonizing leaves. Older larvae consume all but the main veins 

and are less gregarious. Mature larvae drop to the ground and wander 

before pupating in the soil, where they overwinter. Outbreaks occur 

infrequently. There is one generation per year in most parts of the range. 

Defoliation can be significant in some years, but little harm results unless 

trees are under additional stress from other factors.

This species feeds primarily on oaks (Quercus).

This species occurs in much of the eastern United States and southern 

Canada, west to Minnesota and Texas, although it is not common in the 

southeastern United States. 

Hosts Commonly Attacked

Distribution

Images of 

Orangestriped Oakworm

Figure 1. Adults of 

orangestriped oakworm, 

Anisota senatoria. 

(John Wheatley, John B. 

Wheatley, Bugwood.org)
558 Forest Pest Insects in North America:

Images of Orangestriped 

Oakworm (continued)

Figure 2. Eggs of orangestriped oakworm. (John Wheatley, John B. Wheatley)

Figure 3. Young larvae of orangestriped oakworm. (Lance S. Risley, William 

Paterson University, Bugwood.org)

Figure 4. Close up of mature orangestriped oakworm caterpillar. (Lacy L. Hyche, 

Auburn University, Bugwood.org)
A Photographic Guide 559

Images of Orangestriped 

Oakworm (continued)

Figure 5. Defoliation by larvae of orangestriped oakworm. (Erich G. Vallery, 

USDA Forest Service - SRS-4552, Bugwood.org

Important Biological Control 

Agents Related to this 

Pest Species

Parasitoids that have been reared in Virginia from orangestriped 

oakworm larvae or pupae include Hyposoter fugitivus (Say) 

(Ichneumonidae) (in larvae, 3.2 to 9.3 percent) and Lespesia anisotae

(Webber) (Tachinidae) and Belvosia bifasciata (Fabricius) (Tachinidae) 

(in larvae at 10.7 and 0.7 percent, respectively). 

http://www.ct.gov/caes/lib/caes/documents/publications/fact_sheets/

entomology/orangestriped_oakworm.pdf; website of the Connecticut 

Agricultural Experiment Station.

http://www.ag.auburn.edu/enpl/bulletins/orangeoakworm/

orangeoakworm.htm; fact sheet of Auburn University, Auburn, Alabama.

http://www.oakgov.com/msu/assets/docs/publications/e2654_oakworm.

pdf; MSU Extension Bulletin-2654, fact sheet of Michigan State 

University.

Coffelt, M.A. and P.B. Schultz. 1993. Population biology of 

orangestriped oakworm (Lepidoptera: Saturniidae) in southeastern 

Virginia. Journal of Entomological Science 28: 218-229.

Coffelt, M.A. and P.B. Schultz. 1993. Larval parasitism of orangestriped 

oakworm (Lepidoptera: Saturniidae) in the urban shade tree environment. 

Biological Control 3: 127-134.

Coffelt, M.A. and P.B. Schultz. 1989. Development of an aesthetic 

injury level to decrease pesticide use against orange-striped oakworm 

(Lepidoptera: Saturniidae) in an urban pest management project. Journal 

of Economic Entomology 83: 2044-2049. 

Web Links for Information 

on Orangestriped Oakworm

Articles
560 Forest Pest Insects in North America:

156. Pandora Moth, Coloradia pandora Blake (Lepidoptera: Saturniidae)

Orientation to Pest Pandora moth, Coloradia pandora Blake, is an important defoliator 

of pines in the western United States. There are three recognized 

subspecies. Two years are needed to complete the life cycle. Adults 

appear in spring or early summer and eggs hatch in August. Larvae 

crawl up trees and young larvae feed in groups on new foliage. Immature 

larvae spend the winter hibernating in clusters at the base of the needles 

and resume feeding the following spring. In June of the second year, 

mature larvae crawl down trees and pupate in earthen cells in the ground. 

Adults may emerge the following year, or remain as pupae for up to five 

years. Outbreaks occur in regions with soils loose enough for larvae to 

bury themselves for pupation, these being chiefly pumice or decomposed 

granite soils. Large and economically important outbreaks have occurred 

in the past and these seem to reoccur at 20-30 year intervals, lasting 6 to 

8 years each. Because each generation requires two years for completion 

and populations are synchronized, feeding is concentrated in alternate 

years, which allows many trees to recover and survive. In non-outbreak 

years, this insect is uncommon. 

This species feeds primarily on ponderosa (Pinus ponderosa Douglas 

ex C. Lawson), lodgepole (P. contorta Douglas) and Jeffrey (P. jeffreyi

Balf.) pines, but other pines are also sometimes attacked.

This species occurs in the United States west of the Rocky Mountains, 

except for Idaho and Washington.

Hosts Commonly Attacked

Distribution

Images of 

Pandora Moth

Figure 1. Adults 

of Pandora moth, 

Coloradia pandora

(top, female; bottom, 

male). (Top: USDA 

Forest Service Archive, 

USDA Forest Service, 

Bugwood.org; bottom: 

Terry Spivey, USDA 

Forest Service, 

Bugwood.org)
A Photographic Guide 561

Images of Pandora Moth

(continued)

Figure 2. Eggs of 

Pandora moth. 

(Darrell Ross, Oregon 

State University, 

Bugwood.org)

Figure 3. Young larva 

of Pandora moth (top 

photo), and older larvae 

(middle and bottom 

photos; note: upper 

larvae in bottom photo 

is infected with a virus). 

(Top: Darrell Ross, 

Oregon State University, 

Bugwood.org; middle: 

USDA Forest Service 

- Region 2 - Rocky 

Mountain Region 

Archive, USDA Forest 

Service, Bugwood.org; 

bottom: Donald Owen, 

California Department 

of Forestry and 

Fire Protection, 

Bugwood.org)
562 Forest Pest Insects in North America:

Images of Pandora Moth

(continued)

Figure 4. Pupae of 

Pandora moth. 

(Darrell Ross, Oregon 

State University, 

Bugwood.org)

Figure 5. Ponderosa 

pines defoliated by 

Pandora moth. (Bruce 

Hostetler, USDA Forest 

Service, Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

During epidemics, populations of Pandora moth are affected by 

many natural mortality factors, including a wilting virus (likely a 

polynucleohedrosis virus) of the mature larvae, small mammal predators 

of the pupae in the soil, and various parasitoids. 

http://www.forestpests.org/acrobat/pandora.pdf; full text of article: 

Carolin, V.M., Jr., and J.A.E. Knopf. 1968. The Pandora Moth. U.S. 

Department of Agriculture, Forest Service, Forest Pest Leaflet 114.

http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fsbdev2_043666.

pdf; USDA Forest Service leaflet on Pandora moth.

Schmid, J.M. and D.D. Bennett. 1986. The North Kaibab Pandora moth 

outbreak 1978-1984. USDA Forest Service, Rocky Mountain Forest 

and Range Experiment Station, Fort Collins, Colorado, USA, General 

Technical Report RM-153: 18 p. 

Speer, J.H., T.W. Swetnam, B.E. Wickman, and A. Youngblood. 2001. 

Changes in Pandora moth outbreak dynamics during the past 622 years. 

Ecology 82: 679-697. 

Speer, J.H. and R.L. Holmes. 2004. Effects of Pandora moth outbreaks 

on ponderosa pine wood volume. Tree-Ring Research 60: 69-76.

Web Links for Information 

on Pandora Moth

Articles
A Photographic Guide 563

157. European Gypsy Moth, Lymantria dispar (L.) (Lepidoptera: 

Lymantriidae)

Orientation to Pest European gypsy moth, Lymantria dispar (L.), is an invasive species in 

the United States that has been a major forest pest for over a century. Its 

damage consists of defoliation of deciduous forests and trees in spring 

and early summer. Efforts to control this species with introduced natural 

enemies began around 1900 and currently it is under good control in 

New England, but outbreaks still occur to the west and south, where the 

pest continues to invade. There is one generation a year and the species 

overwinters as eggs on trees or various objects. Spread occurs locally 

by wind-blown young caterpillars and over long distances by human 

movement of egg masses. Female moths cannot fly. Both adults and 

caterpillars are easily recognized.

The larvae of this species feed on most species of deciduous trees, 

especially oaks (Quercus).

Hosts Commonly Attacked

Distribution Figure 1. World 

distribution of European 

gypsy moth, Lymantria 

dispar. (USDA Forest 

Service - Northeastern 

Research Station; 

“Gypsy Moth in North 

America”)

Images of European

Gypsy Moth

Figure 2. Female 

European gypsy moth 

(on egg mass). Note 

white wings with brown 

zigzag lines. (Steven 

Katovich, USDA Forest 

Service, Bugwood.org)
564 Forest Pest Insects in North America:

Images of European

Gypsy Moth (continued)

Figure 3. Male European 

gypsy moth. Note brown 

wings and feather-like 

antennae. (James 

A. Copony, Virginia 

Department of Forestry, 

Bugwood.org)

Figure 4. Newly hatched caterpillars of European gypsy moth on egg mass, 

preparing to disperse by crawling or blowing in the wind on silk threads. 

(Milan Zubrik, Forest Research Institute - Slovakia, Bugwood.org)

Figure 5. Mature European gypsy moth caterpillar. Note series of blue or red 

spots on back, plus clusters of hairs on sides. (USDA Forest Service Archive, 

USDA Forest Service, Bugwood.org)
A Photographic Guide 565

Images of European

Gypsy Moth (continued)

Figure 6. Pupae of 

European gypsy moth 

in silken cradle (far 

left). Threads cut 

away to show detail. 

Female pupa above, 

male below. (Milan 

Zubrik, Forest Research 

Institute - Slovakia, 

Bugwood.org)

Figure 7. Defoliation from European gypsy moth. (Landesforstpräsidium Sachsen 

Archive, Bugwood.org)

Figure 8. Aerial view of defoliation from European gypsy moth. In the absence of 

effective biological control, widespread defoliation of forest stands can occur in 

late spring. Defoliation areas appear brown on the upper slope. (Pennsylvania 

Department of Conservation and Natural Resources - Forestry Archive, 

Bugwood.org)
566 Forest Pest Insects in North America:

Images of European

Gypsy Moth (continued)

Figure 9. The 

nucleopolyhedrosis virus 

of European gypsy moth 

can cause epidemics 

in dense European 

gypsy moth populations 

but comes too late to 

prevent damage. Viruskilled caterpillars hang 

by their legs on tree, 

and fluids from rotting 

cadavers drip onto 

foliage, spreading virus. 

(William M. Ciesla, 

Forest Health 

Management 

International, 

Bugwood.org) 

Figure 10. The fungus Entomophthora maimaiga has emerged as a key 

biological control agent of European gypsy moth in the northeastern United 

States (left, diseased caterpillar; right, fungal protoplasts). (Both photos: 

Andy Liebhold - USDA Forest Service - Northeastern Research Station; 

“Gypsy Moth in North America”) 
A Photographic Guide 567

Images of European

Gypsy Moth (continued)

Figure 11. Compsilura 

concinnata, an important 

tachinid parasitoid of the 

European gypsy moth. 

(Joyce Gross, UCB, 

Bugwood.org)

Figure 12. Cotesia 

melanoscela, a 

parasitoid of European 

gypsy moth larvae. 

(James Lindsey, 

Ecology of Commanster)

Important Biological Control 

Agents Related to this 

Pest Species

Of some 80 species of parasitoids imported and released into the United 

States against this pest, 11 species became established and six are 

believed to have contributed to control of the European gypsy moth: 

(1) Ooencyrtus kuvanae (Howard) (Hymenoptera: Encrytidae); 

(2) Cotesia melanoscela (Ratzeburg) (Hymenoptera: Braconidae); 

(3) Brachymeria intermedia (Nees) (Hymenoptera: Chalcididae); 

(4) Compsilura concinnata (Meigen) (Diptera: Tachinidae); 

(5) Parasetigena silvestris (Robineau-Desvoidy) (Diptera: Tachinidae); 

and (6) Blepharipa pratensis (Meigen) (Diptera: Tachinidae). Effective 

control was achieved in the northeastern United States following the 

accidental introduction of the fungal pathogen Entomophthora maimaiga

Humber, Shimazu, and Soper.

http://www.fs.fed.us/ne/morgantown/4557/gmoth/; a USDA Forest 

Service site that provide information and links to other sites on a variety 

of topics, including distribution, effects on forests, management, and 

natural enemies. 

http://www.na.fs.fed.us/spfo/pubs/fidls/gypsymoth/gypsy.htm; a 

USDA Forest Service leaflet (Forest insect and disease leaflet No. 162) 

covering life cycle, hosts, effects of defoliation, population dynamics, 

management, use of pesticides, and silvicultural treatments. 

Web Links for Information 

on European Gypsy Moth
568 Forest Pest Insects in North America:

Articles Hajek, A.E., J.S. Elkinton, and J.J. Witcosky. 1996. Introduction and 

spread of the fungal pathogen Entomophaga maimaiga (Zygomycetes: 

Entomophthorales) along the leading edge of gypsy moth (Lepidoptera: 

Lymantriidae) spread. Environmental Entomology 25: 1235-1247.

Liebhold, A., J. Elkinton, D. Williams, and R.M. Muzika. 2000. What 

causes outbreaks of the gypsy moth in North America? Population 

Ecology 42: 257-266.

Elkinton, J.S., W.M. Healy, A.M. Liebhold, and J.P. Buonaccorsi. 2002. 

Gypsy moths and forest dynamics. In: McShea, W.J. and W.M. Healy. 

Oak Forest Ecosystems: Ecology and Management for Wildlife. John 

Hopkins University Press. Baltimore, MD, USA: 100-112.
A Photographic Guide 569

158. Asian Pink Moth, Lymantria mathura Moore (Lepidoptera: 

Lymantriidae)

Orientation to Pest Asian pink moth (formerly called “rosy gypsy moth”), Lymantria 

mathura Moore, is an Asian defoliator not yet present in the United 

States, but one that poses a high risk of invasion and potential damage. 

It defoliates a variety of hardwood species and outbreaks may affect 

large areas. During outbreaks, the pest population density may reach 

1000 caterpillars per tree. The species overwinters as eggs containing 

fully developed larvae, ready to hatch. Larvae emerge early in spring 

and disperse and attack buds, then leaves. Most feeding occurs at night. 

Mature larvae pupate in flimsy cocoons on the host tree. Females fly at 

night (1:00-3:00 a.m.) and lay eggs in masses of 150-600 on bark of host 

tree or other objects. There is one generation per year. 

Asian pink moth attacks many species of Betula, Castanea, Juglans, 

Malus, Quercus, Salix, Tilia, Ulmus, and other deciduous trees. Its 

preferred hosts in the Russian Far East include Juglans mandshurica

Maxim., Quercus mongolica Fisch. ex Turcz., and Q. dentata Thunb.

Asian pink moth is native to Asia and is found in the Russian Far 

East, Nepal, Japan, Korea, northern India, and parts of China (Hebei, 

Heilongjiang, Jilin provinces, and western China).

Hosts Commonly Attacked

Distribution

Images of 

Asian Pink Moth

Figure 1. Adults of Asian 

pink moth, Lymantria 

mathura (top, male; 

bottom, female). 

(Top: DAFF Archive, 

Bugwood.org; bottom: 

David Mohn, Critters 

Page [Creatures 

Great and Small], 

Bugwood.org)
570 Forest Pest Insects in North America:

Images of Asian 

Pink Moth (continued)

Figure 2. Comparison of 

the female of Asian pink 

moth (bottom) to that of 

gypsy moth (Lymantria 

dispar [L.]), top. (USDA 

APHIS PPQ Archive, 

USDA APHIS PPQ, 

Bugwood.org)

Figure 3. Egg mass of Asian pink moth. (David Mohn, Critters Page [Creatures 

Great and Small], Bugwood.org)
A Photographic Guide 571

Images of Asian 

Pink Moth (continued)

Figure 4. Young larvae 

of Asian pink moth. 

(David Mohn, 

Critters Page [Creatures 

Great and Small], 

Bugwood.org)

Figure 5. Mature larvae 

of Asian pink moth. 

(USDA APHIS PPQ 

Archive, USDA APHIS 

PPQ, Bugwood.org)

Figure 6. Pupa of Asian 

pink moth. (David Mohn, 

Critters Page [Creatures 

Great and Small], 

Bugwood.org)
572 Forest Pest Insects in North America:

Important Biological Control 

Agents Related to this 

Pest Species

In Korea, natural enemies associated with Asian pink moth include 

Cotesia melanoscela (Ratzberg), the dominant larval parasitoid, and 

Brachymeria lasus (Walker), the most important pupal parasitoid. 

http://www.eppo.org/QUARANTINE/insects/Lymantria_mathura/DS_

Lymantria_mathura.pdf; detailed fact sheet of the European quarantine 

organization EPPO.

http://www.aphis.usda.gov/plant_health/plant_pest_info/pest_detection/

downloads/pra/lmathurapra.pdf; APHIS (USDA) risk assessment for 

Asian pink moth to the United States. 

Zlotina, M.A., V.C. Mastro, D.E. Leonard, and J.S. Elkinton. 1998. 

Survival and development of Lymantria mathura on North American, 

Asian, and European tree species. Journal of Economic Entomology

91: 1162-1166.

Anon. 2005. Lymantria mathura. EPPO Bulletin 35(3): 464-467.

Web Links for Information 

on Asian Pink Moth

Articles
A Photographic Guide 573

159. Nun Moth, Lymantria monacha Moore (Lepidoptera: Lymantriidae)

Orientation to Pest Nun moth, Lymantria monacha Moore, is a Eurasian species that has not 

yet invaded North America but is a species of high concern. Outbreaks 

of the nun moth are often observed in Scots pine (Pinus sylvestris L.) 

and Norway spruce stands (Picea abies [L.] Karst.), but many conifers 

and broadleaf trees are also hosts. The biology closely resembles that 

of the gypsy moth (Lymantria dispar [L.]), except that females of nun 

moth can fly, which they do at night. The species overwinters as eggs 

containing fully developed larvae, which emerge when buds on host trees 

are opening. Young larvae feed on buds in groups but after the first instar, 

larvae consume mature needles and feed alone. Pupation takes place on 

the host tree and by mid-summer adults are in flight. Adults lay eggs in 

cracks of bark on the host tree or in crevices of other objects in masses of 

70 to 300 eggs. Egg masses may be moved on firewood or other material. 

There is one generation per year. 

Outbreaks of the nun moth are often observed in Scots pine (P. sylvestris) 

and Norway spruce (P. abies) stands. However, most conifers and many 

broad-leaved tree species may also be used as food plants. 

Nun moth is widely distributed and is found in China, Japan, Russia, and 

Europe. 

Hosts Commonly Attacked

Distribution

Images of 

Nun Moth

Figure 1. Adults of 

nun moth, Lymantria 

monacha; top, male and 

bottom, female. (Note: 

this species has a wide 

range of color variation, 

which is not captured 

in these photos.) (Both 

photos: DAFF Archive, 

Bugwood.org)
574 Forest Pest Insects in North America:

Images of Nun Moth

(continued)

Figure 2. Adult female 

nun moth in resting 

position. (Hannes 

Lemme, Bugwood.org)

Figure 3. Egg mass of 

nun moth. (Stanislaw 

Kinelski, Bugwood.org)
A Photographic Guide 575

Images of Nun Moth

(continued)

Figure 4. Young larvae 

of nun moth. (Note: like 

adults, larvae vary in 

color.) (Both photos: 

Stanislaw Kinelski, 

Bugwood.org)

Figure 5. Mature larva 

of nun moth. (Stanislaw 

Kinelski, Bugwood.org)
576 Forest Pest Insects in North America:

Images of Nun Moth

(continued)

Figure 6. Pupae of nun 

moth. (Hannes Lemme, 

Bugwood.org)

Figure 7. Small conifer 

killed by nun moth. 

(Landesforstpräsidium 

Sachsen Archive, 

Bugwood.org)

Figure 8. Norway spruce 

stand defoliated by 

nun moth. (Jan Liska, 

Forestry and Game 

Management Research 

Institute, Bugwood.org)
A Photographic Guide 577

Many natural enemies have been recorded attacking nun moth, usually 

during outbreaks or in the decline phase as populations collapse. These 

include many species of parasitoids (mostly tachinid and sarcophagid 

flies and braconid wasps). See Van Driesche et al. (1996) for details. A 

baculovirus is also known from this species. However, there is limited 

experimental evidence about the role such agents play in regulation of 

the species or curtailment of outbreaks. 

http://wiki.bugwood.org/Archive:Atlas/Lymantria_monacha#Biology; 

short fact sheet of Bugwood Wiki.

ftp://ftp.fao.org/docrep/fao/011/i0640e/i0640e10q.pdf; fact sheet of the 

United Nations FAO group. 

http://www.inspection.gc.ca/english/plaveg/pestrava/lymmon/tech/

lymmone.shtml; fact sheet of the Canadian Food Inspection Agency.

http://www.nrs.fs.fed.us/disturbance/invasive_species/nun_moth/; 

contains information on the species’ biology, photos, a reference list, 

and a pest alert.

Van Driesche, R.G., S. Healy, and R.C. Reardon. 1996. Biological 

Control of Arthropod Pests of the Northeastern and North Central 

Forests in the United States: A review and recommendations.

FHTET 96-19, USDA Forest Service, Morgantown. (Available 

at http://www.forestpestbiocontrol.info/fact_sheets/documents/

arthropodpestsnortheastern_northcentral.pdf).

Keena, M.A., K.S. Shields, and M. Torsello. 1998. Nun moth: potential 

new pest. Pest Alert NA-PR-95-98. USDA Forest Service, Northeastern 

Area, State and Private Forestry: 2 p.

Keena, M.A. 2003. Survival and development of Lymantria monacha

(Lepidoptera: Lymantriidae) on North American and introduced Eurasian 

tree species. Journal of Economic Entomology 96: 43-52.

Prestemon, J.P., J.A. Turner, J. Buongiorno, S.S. Zhu, and R.H. Li. 

2008. Some timber product market and trade implications of an invasive 

defoliator: the case of Asian Lymantria in the United States. Journal of 

Forestry 106: 409-415.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Nun Moth

Articles
578 Forest Pest Insects in North America:

160. Browntail Moth, Euproctis chrysorrhoea L. (Lepidoptera: Lymantriidae)

Orientation to Pest Browntail moth, Euproctis chrysorrhoea L., is an invasive species in 

North America whose effects on trees is similar to that of gypsy moth 

(Lymantria dispar [L.]), being a defoliator of a wide range of deciduous 

broadleaf trees. Introduced into North America in the later 19th century, 

by 1914 it had infested a wide band of coastal and inland New England. 

In addition to widespread defoliation of many types of deciduous 

hardwood trees, including many fruit trees, the species also was a threat 

to public health because of the severe skin rashes from the caterpillar’s 

hairs. These, if inhaled, could cause illness leading to death in some 

cases. By 1922, its range began to quickly collapse and currently the 

moth is found only in a few small coastal enclaves. While the cause of 

this decline was not understood at the time, it was subsequently proved 

to be caused by the action of Compsilura concinnata (Meigen), a 

polyphagous tachinid introduced against it and the gypsy moth.

Browntail moth feeds on most species of deciduous broadleaf trees, 

especially species of apple (Malus), pear (Pyrus), plum (Prunus), oak 

(Quercus), willow (Salix), elm (Ulmus), and maple (Acer).

At the height of its invasion, browntail moth was found in much of 

New England, but it is currently found only at the very tip of Cape Cod, 

Massachusetts, and on some islands in Casco Bay, near Portland, Maine. 

Hosts Commonly Attacked

Distribution

Figure 1. Historical 

and current distribution 

of browntail moth, 

Euproctis chrysorrhoea, 

in North America. 
A Photographic Guide 579

Images of 

Browntail Moth

Figure 2. Female browntail moth. (Jan Samanek, State Phytosanitary 

Administration, Bugwood.org)

Figure 3. Egg mass of browntail moth. (Jan Samanek, State Phytosanitary 

Administration, Bugwood.org)

Figure 4. Young 

browntail moth 

caterpillars on web. 

(Jan Samanek, 

State Phytosanitary 

Administration, 

Bugwood.org)
580 Forest Pest Insects in North America:

Images of Browntail 

Moth (continued)

Figure 5. Mature browntail moth caterpillars. (Jan Samanek, State Phytosanitary 

Administration, Bugwood.org)

Figure 7. Skin rash from 

contact with browntail 

moth caterpillars. 

(Jan Samanek, 

State Phytosanitary 

Administration, 

Bugwood.org)

Figure 6. Side view of browntail moth caterpillar showing prominent hairs that 

cause severe skin rash. (Jan Samanek, State Phytosanitary Administration, 

Bugwood.org)
A Photographic Guide 581

Images of Browntail 

Moth (continued)

Figure 10. Compsilura 

concinnata, an important 

tachinid parasitoid of the 

European gypsy moth. 

(Joyce Gross, UCB, 

Bugwood.org)

Figure 8. Pupae of browntail moth in web. (Jan Samanek, State Phytosanitary 

Administration, Bugwood.org)

Figure 9. Defoliated trees and old browntail moth webbing. (Milan Zubrik, Forest 

Research Institute - Slovakia, Bugwood.org)
582 Forest Pest Insects in North America:

Important Biological Control 

Agents Related to this 

Pest Species

Elkinton et al. (2006) demonstrated that C. concinnata (Diptera: 

Tachinidae) was likely the agent responsible for the extinction of 

browntail moth from much of its former range in North America in the 

early part of the 20th century. Two other tachinids, Townsendiellomyia 

nidicola and Carcelia laxifrons, both browntail moth specialists were 

also introduced and successfully established at the same time as C. 

concinnata. More recently, a nucleopolyhedrosis virus from England, 

specific to the moth has been released and established in Maine, but 

impacts on remaining populations were not yet clear as of 2010. Many 

browntail moth populations in Maine have been heavily affected by a 

naturally occurring fungal pathogen, Entomophaga aulicae (Reichardt in 

Bail) Humber.

http://www.maine.gov/doc/mfs/btm.htm; leaflet from Maine Department 

of Conservation that includes recommendations for chemical controls 

and other measures.

Elkinton, J.S., D. Parry, and G.H. Boettner. 2006. Implicating an 

introduced generalist parasitoid in the invasive browntail moth’s 

enigmatic demise. Ecology 87: 2664-2672.

Elkinton, J.S., E. Preisser, G. Boettner, and D. Parry. 2008. Factors 

influencing larval survival of the invasive browntail moth (Lepidoptera: 

Lymantriidae) in relict North American populations. Environmental 

Entomology 37: 1429-1437. (Available at http://cels.uri.edu/preisserlab/

media/publications/preisser/Env%20Ent%202008%20(37,6)%201429-

1437.pdf). 

Web Links for Information 

on Browntail Moth

Articles
A Photographic Guide 583

161. Pine Tussock Moth, Dasychira pinicola (Dyar) (Lepidoptera: 

Lymantriidae)

Orientation to Pest Pine tussock moth, Dasychira pinicola (Dyar), is a native North 

American tussock moth. It is known for sudden eruptions in population 

that quickly subside and may not occur again for many years. It is found 

in southeastern Canada and from the northeastern United States west 

to Minnesota. The larvae feed on various conifers, especially on jack 

pine (Pinus banksiana Lamb.) Outbreaks, when they do occur, can be 

extensive and damaging since the caterpillar stage consumes both new 

and old foliage, leaving host conifers completely defoliated. In the last 

century there have been several large outbreaks on jack pine in the Lakes 

States. In the Lake States, moths fly in mid-summer and eggs are laid 

in irregular clusters on or near the female pupal case, on the needles 

or the trunk. Eggs hatch later in the summer and young larvae feed on 

needles until they reach the second or third instar, when they go into 

hibernation for the winter. Larvae resume feeding in the spring, at first 

eating staminate flowers and young needles. Later, old-needles are also 

eaten. Fully grown larvae spin cocoons on needles or twigs, where they 

also pupate. Moths emerge shortly thereafter. There is one generation per 

year. 

The caterpillar stage of pine tussock moth feeds on various conifers, 

including jack (P. banksiana), red (P. resinosa Sol. ex Aiton), and 

eastern white (P. strobus L.) pines, spruce (Picea) and balsam fir (Abies 

balsamea [L.] Mill.).

Pine tussock moth is found in southeastern Canada and from the 

northeastern United States west to Minnesota.

Hosts Commonly Attacked

Distribution

Images of 

Pine Tussock Moth

Figure 1. Adult of pine 

tussock moth, Dasychira 

pinicola. (Gordon 

Harrison)
584 Forest Pest Insects in North America:

Images of Pine

Tussock Moth (continued)

Figure 2. Eggs of the pine tussock moth. (USDA Forest Service - Northeastern 

Area Archive, USDA Forest Service, Bugwood.org)

Figure 3. Larva of 

pine tussock moth. 

(USDA Forest Service 

- Northeastern Area 

Archive, USDA Forest 

Service, Bugwood.org)

Figure 4. Pupa of pine tussock moth. (USDA Forest Service - Northeastern Area 

Archive, USDA Forest Service, Bugwood.org)
A Photographic Guide 585

Images of Pine

Tussock Moth (continued)

Figure 5. Jack pines damaged by pine tussock moth. (Minnesota Department 

of Natural Resources Archive, Minnesota Department of Natural Resources, 

Bugwood.org)

Natural enemies of this species have been studied during outbreaks that 

occurred in Wisconsin in the 1960s. Thirty-one parasitic species were 

reared during that study. Eight insect predators and four pathogens were 

also reported. Parasitism levels were significant in the egg, larval and 

pupal stages (see Sreenivasum et al. 1972 for details).

None

Sreenivasam, D.D., D.M. Benjamin, and D.D. Walgenbach. 1972. 

The bionomics of the pine tussock moth. Research Bulletin No. 282. 

School of Natural Resources, College of Agriculture and Life Sciences, 

University of Wisconsin, Madison: 36 p.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Pine Tussock Moth

Articles
586 Forest Pest Insects in North America:

162. Whitemarked Tussock Moth, Orgyia leucostigma (J. E. Smith) 

(Lepidoptera: Lymantriidae)

Orientation to Pest Whitemarked tussock moth, Orgyia leucostigma (J. E. Smith), is a 

native North American tussock moth whose larvae feed on a variety of 

deciduous and coniferous trees. The species is found in most of eastern 

Canada and the eastern United States. This tussock moth passes the 

winter as eggs, which hatch in spring and thereafter young larvae often 

spin down on silk threads and balloon to new host plants. Young larvae 

skeletonize leaves of host trees, while older larvae consume whole leaves 

(eating all but the major veins). Cocoons are formed in bark crevices 

or between branches, and adults emerge in a few weeks. Females are 

wingless and lay eggs in masses. There are one or two generations per 

year depending on the region. Damage to forest trees is minor and this 

species is better known as a pest of shade or fruit trees in urban areas and 

in intensively managed plantations of Christmas trees.

Whitemarked tussock moth exploits a broad range of plant species and 

has been reported to cause significant damage to many tree species, 

including apple (Malus), basswood (Tilia), elm (Ulmus), poplar 

(Populus), Norway maple (Acer platanoides L.), silver maple (Acer 

saccharinum L.), sycamore (Platanus), paper birch (Betula papyrifera

Marsh.), yellow birch (Betula alleghaniensis Britt.), larch (Larix), and 

balsam fir (Abies balsamea [L.] Mill.).

Whitemarked tussock moth is found throughout eastern Canada and the 

eastern United States.

Hosts Commonly Attacked

Distribution

Figure 1. Adults of whitemarked tussock moth, Orgyia leucostigma: left, winged 

male; right, wingless female. (Left: James Solomon, USDA Forest Service, 

Bugwood.org; right: North Carolina Forest Service Archive, Bugwood.org)

Images of Whitemarked 

Tussock Moth
A Photographic Guide 587

Images of Whitemarked 

Tussock Moth (continued)

Figure 2. Flightless female of whitemarked tussock moth producing her egg 

mass. (John L. Foltz, University of Florida, Bugwood.org)

Figure 3. Larvae of 

whitemarked tussock 

moth: top, dorsal view; 

bottom, lateral view. 

(Top: John H. Ghent, 

USDA Forest Service, 

Bugwood.org; bottom: 

Connecticut Agricultural 

Experiment Station 

Archive, Connecticut 

Agricultural Experiment 

Station, Bugwood.org)
588 Forest Pest Insects in North America:

Images of Whitemarked 

Tussock Moth (continued)

Figure 4. Top, pupae of 

whitemarked tussock 

moth (removed from 

cocoons); bottom, 

cocoons of whitemarked 

tussock moth. (Top: 

Robert L. Anderson, 

USDA Forest Service, 

Bugwood.org; bottom: 

James Solomon, 

USDA Forest Service, 

Bugwood.org)

Figure 5. Feeding damage of whitemarked tussock moth larvae. (James 

Solomon, USDA Forest Service, Bugwood.org)
A Photographic Guide 589

Two strains of nucleopolyhedroviruses, one specific to whitemarked 

tussock moth and the other to Douglas fir tussock moth, Orgyia 

pseudotsugata (McDunnough), have been found to cause widespread 

mortality in populations of whitemarked tussock moth and are being 

developed as possible biological control agents in Christmas tree 

plantations (balsam fir) in eastern Canada.

http://www.ag.auburn.edu/enpl/bulletins/whitemarkedtussock/

whitemarkedtussock.htm; fact sheet of Auburn University.

http://www.ag.auburn.edu/enpl/bulletins/whitemarkedtussock/

whitemarkedtussock.htm; fact sheet of the USDA Forest Service, 

Forest Health Protection, Southern Region.

http://insects.tamu.edu/fieldguide/cimg313.html; fact sheet of Texas 

A&M University.

Thurston, G.S. 2001. Orgyia leucostigma (J. E. Smith), whitemarked 

tussock moth (Lepidoptera: Lymantriidae). In: Mason, P.G. and J.T. 

Huber. Biological Control Programmes in Canada, 1981-2000. CABI 

Publishing, Wallingford, UK: 201-203.

Medina, R.F. and P. Barbosa. 2002. Predation of small and large Orgyia 

leucostigma (J. E. Smith) (Lepidoptera: Lymantriidae) larvae by 

vertebrate and invertebrate predators. Environmental Entomology 31: 

1097-1102. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information on

Whitemarked Tussock Moth

Articles
590 Forest Pest Insects in North America:

163. Douglas-fir Tussock Moth, Orgyia pseudotsugata (McDunnough) 

(Lepidoptera: Lymantriidae)

Orientation to Pest The Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough), 

is a native defoliator of major importance in the interior Douglasfir and true fir forests of western North America, where is defoliates 

Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) and various true 

firs (Abies). Adults emerge in late summer or early fall. The flightless 

females remain on their cocoons, where they mate and lay their egg 

mass. Eggs overwinter and hatch the following spring when new foliage 

has appeared. Young larvae crawl to new needles and begin feeding, 

but small larvae may disperse by dropping on silken threads and being 

blown by the wind, especially when new foliage is not available. Young 

larvae feed on the unfolding new needles, while older larvae feed on 

both new and old foliage. Foliage of heavily infested forest stands turns 

distinctly brownish. By late summer, mature larvae form cocoons either 

on the foliage when densities are low or on tree trunks and objects on 

the ground when densities are high. New adults emerge in a few weeks 

to complete the life cycle. The cocoons and egg masses are among the 

most conspicuous evidence of tussock moth abundance. There is one 

generation a year. Periodic large scale outbreaks have occurred. These 

outbreaks develop explosively but subside abruptly after about 3 years. 

Between outbreaks this insect is seldom seen. 

Douglas-fir tussock moth feeds on Douglas-fir (P. menziesii), and 

various native firs, especially grand (Abies grandis [Douglas ex D. Don] 

Lindley), white (A. concolor [Gordon] Lindley ex Hildebrand), and 

subalpine fir (A. lasiocarpa [Hooker] Nuttal).

Douglas-fir tussock moth is found from southern British Columbia 

through the eastern half of the Pacific coast states. It is also found in the 

Rocky Mountain States, south to Arizona and New Mexico.

Hosts Commonly Attacked

Distribution

Images of Douglas-fir

Tussock Moth

Figure 1. Adults of Douglas-fir tussock moth, Orgyia pseudotsugata: left, male; 

right, wingless female on her cocoon. (Both photos: Ladd Livingston, Idaho 

Department of Lands, Bugwood.org)
A Photographic Guide 591

Images of Douglas-fir

Tussock Moth (continued)

Figure 2. Egg masses 

(top) of Douglas-fir 

tussock moth and egg 

mass (bottom) with 

newly hatched larvae. 

(Top: Kenneth E. 

Gibson, USDA Forest 

Service, Bugwood.org; 

bottom: USDA Forest 

Service - Region 4 

- Intermountain Archive, 

USDA Forest Service, 

Bugwood.org)

Figure 4. Cocoons of Douglas-fir tussock moth (left), and close up (right). (Left: 

William M. Ciesla, Forest Health Management International, Bugwood.org; right: 

USDA Forest Service - Ogden Archive, USDA Forest Service, Bugwood.org)

Figure 3. Mature larvae 

of Douglas-fir tussock 

moth. (Ladd Livingston, 

Idaho Department of 

Lands, Bugwood.org)
592 Forest Pest Insects in North America:

Images of Douglas-fir

Tussock Moth (continued)

Figure 5. Feeding 

damage of Douglasfir tussock moth on 

Douglas-fir trees. 

(Dave Powell, 

USDA Forest Service, 

Bugwood.org)

Figure 6. Defoliation and tree mortality caused by Douglas-fir tussock moth. 

(David McComb, USDA Forest Service, Bugwood.org)
A Photographic Guide 593

The Douglas-fir tussock moth has many natural enemies including 

a nucleopolyhedrosis virus that is capable of dramatically reducing 

populations, but which usually appears after trees have been seriously 

defoliated. Many parasitoids are known to attack this species, including 

a Telonomus sp. egg parasitoid, and the larval parasitoids Phobocampe 

pallipes (Provancher) (Ichneumonidae) and Carcelia yalensis Sellers 

(Tachinidae). Parasitoids sometimes hasten the decline of an outbreak.

http://insects.ippc.orst.edu/pdf/reb130.pdf.

http://www.forestry.ubc.ca/fetch21/DFTM/dftmtot.html; fact sheet of the 

University of British Columbia.

http://ext.nrs.wsu.edu/forestryext/foresthealth/notes/douglasmoth.htm; 

fact sheet of Washington State University. 

http://www.fs.fed.us/r6/nr/fid/fidls/fidl-86.pdf; USDA Forest Service 

Forest Insect and Disease Leaflet.

Mills, N.J. and F. Schoenberg. 1985. Possibilities for the biological 

control of the Douglas-fir tussock moth, Orgyia pseudotsugata

(Lymantriidae), in Canada, using natural enemies from Europe. 

Biocontrol News and Information 6(1): 7-18.

Dahlsten, D.L., D.L. Rowney, and W.A. Copper. 1992. Comparison of 

artificial pupation shelters and other monitoring methods for endemic 

populations of Douglas-fir tussock moth, Orgyia pseudotsugata

(McDunnough) (Lepidoptera: Lymantriidae). The Canadian 

Entomologist 124: 359-369.

Otvos, I.S., R.F. Shepherd, and J.C. Cunningham. 2001. Orgyia 

pseudotsugata (McDunnough), Douglas-fir tussock moth (Lepidoptera: 

Lymantriidae). In: Mason, P.G. and J.T. Huber (eds.). Biological Control 

Programmes in Canada, 1981-2000. CABI Publishing, Wallingford, UK: 

204-212. 

Otvos, I.S. and R.F. Shepherd. 1991. Integration of early virus treatment 

with a pheromone detection system to control Douglas-fir tussock moth, 

Orgyia pseudotsugata (Lepidoptera: Lymantriidae), populations at 

pre-outbreak levels. Forest Ecology and Management 39: 143-151.

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on Douglas-fir Tussock Moth

Articles
594 Forest Pest Insects in North America:

164. Poplar Tentmaker, Clostera inclusa (Hübner) (Lepidoptera: 

Notodontidae)

Orientation to Pest Poplar tentmaker, Clostera inclusa (Hübner), is a native notodontid 

moth that feeds on poplar (Populus) and willow (Salix) and is found 

from southern Canada to Georgia, and west to Colorado. Adults fly from 

March to July in the southern United States and from July to August 

in the northern part of its U.S. range. Eggs are laid in clusters on the 

undersides of leaves. Larvae are gregarious and live in tents, which they 

construct by webbing together the edges of several leaves. The larvae 

feed through the growing season and move to the ground in late fall, 

where they pupate in loose cocoons and spend the winter. There are one 

or two generations per year, depending on the location. Small groups of 

open-grown trees may be defoliated. 

This caterpillar feeds on poplar (Populus) and willow (Salix).

Poplar tentmaker is found from southern Canada to Georgia, west to 

Colorado.

Hosts Commonly Attacked

Distribution

Images of 

Poplar Tentmaker

Figure 1. Adult of poplar 

tentmaker, Clostera 

inclusa. (Marvin Smith, 

Bugwood.org)
A Photographic Guide 595

Images of Poplar 

Tentmaker (continued)

Figure 2. Egg mass of poplar tentmaker. (James Solomon, USDA Forest Service, 

Bugwood.org)

Figure 3. Mature larvae of poplar tentmaker. (Robert L. Anderson, USDA Forest 

Service, Bugwood.org) 

Figure 4. Cocoon of poplar tentmaker. (William A. Carothers, USDA Forest 

Service, Bugwood.org)
596 Forest Pest Insects in North America:

Images of Poplar 

Tentmaker (continued)

Figure 5. Poplars defoliated by poplar tentmaker. (James Solomon, USDA Forest 

Service, Bugwood.org)

Figure 6. Stand of eastern cottonwood (Populus deltoides ssp. deltoides Bartram 

ex Marsh.) defoliated by poplar tentmaker. (James Solomon, USDA Forest 

Service, Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

Ladybird beetles may consume the eggs of this species.

http://www.ag.auburn.edu/enpl//bulletins/poplartentmaker/

poplartentmaker.htm; fact sheet of Auburn University on biology and 

control.

http://www.entomology.umn.edu/cues/Web/190PoplarTentmaker.pdf; 

fact sheet from the University of Minnesota.

Solomon, J.D. and F.L. Oliveria. 1993. Evaluation of poplar tentmaker 

defoliation on growth and survival of older cottonwood plantations. 

Research Paper - Southern Forest Experiment Station, USDA Forest 

Service (SO-271): 6 p. 

Web Links for Information 

on Poplar Tentmaker

Articles
A Photographic Guide 597

165. Saddled Prominent, Heterocampa guttivitta (Walker) (Lepidoptera: 

Notodontidae)

Orientation to Pest Saddled prominent, Heterocampa guttivitta (Walker), is a native North 

American notodontid that occurs in southeastern Canada and throughout 

the eastern United States, feeding on beech (Fagus grandifolia Ehrh.), 

paper birch (Betula papyrifera Marshall), sugar maple (Acer saccharum

Marshall) and many other hardwoods. Adults fly in spring and lay up to 

500 eggs singly on the host’s leaves. Young larvae skeletonize leaves, 

while older ones consume all but the larger veins. During outbreaks, 

larvae may move from tree to tree. In mid-summer, larvae move into 

the leaf litter, where they pupate and then pass the winter. There is one 

generation per year in the northern part of the insect’s range. Periodic 

outbreaks have occurred, especially in the northeastern United States, 

and these may defoliate, and sometimes kill or top-kill affected trees.

This caterpillar feeds most commonly on American beech 

(F. grandifolia), paper birch (B. papyrifera), and sugar maple 

(A. saccharum).

The saddled prominent occurs in southeastern Canada and throughout the 

eastern United States.

Hosts Commonly Attacked

Distribution

Images of 

Saddled Prominent

Figure 1. Adult of 

saddled prominent, 

Heterocampa guttivitta. 

(Mark Dreiling, 

Bugwood.org)
598 Forest Pest Insects in North America:

Images of Saddled 

Prominent (continued)

Figure 2. Eggs of 

saddled prominent. 

(Thérèse Arcand 

- Natural Resources 

Canada, Canadian 

Forest Service)

Figure 3. Young larvae 

of saddle prominent 

have structures near 

head that resemble 

horns. (Lacy L. Hyche, 

Auburn University, 

Bugwood.org)

Figure 4. Mature larva 

of saddled prominent. 

(Ronald S. Kelley, 

Vermont Department 

of Forests, Parks 

and Recreation, 

Bugwood.org)

Figure 5. Pupal cell 

(left) and pupa (right, 

removed from cell) of 

saddled prominent. 

(Thérèse Arcand 

- Natural Resources 

Canada, Canadian 

Forest Service)
A Photographic Guide 599

Images of Saddled 

Prominent (continued)

Figure 6. Appearance 

of saddle prominent 

feeding on maple. 

(USDA Forest Service, 

Forest Insect & Disease 

Leaflet 167)

Important Biological Control 

Agents Related to this 

Pest Species

The parasitoids recorded from various life stages of the saddled 

prominent include the scelionid egg parasitoid Telenomus coelodasidis

Ashmead and the larval parasitoids Phobocampe pallida (Cushman) 

(Ichneumonidae) and Eulophus anomocerus (J.C. Crawford) 

(Eulophidae), both of which were uncommon (<1 percent parasitism). 

Another ichneumonid, Cratichneumon sublatus (Cresson), is the main 

pupal parasitoid, attacking 1-17 percent under outbreak conditions and 

32-57 percent in the year following the collapse of its host’s population. 

http://www.na.fs.fed.us/spfo/pubs/fidls/saddled/fidl-sp.htm; USDA 

Forest Service Pest and Disease Leaflet No. 167 on biology and control.

http://wiki.bugwood.org/Heterocampa_guttivitta; Bugwood Wiki fact 

sheet on biology and distribution.

Fisher, G.T. 1970. Parasites and predators of the species of a saddled 

prominent complex at Groton, Vermont. Journal of Economic 

Entomology 63: 1613-1614.

Allen, D.C. 1972. Insect parasites of the saddled prominent, 

Heterocampa guttivitta (Lepidoptera: Notodontidae) in the northeastern 

United States. The Canadian Entomologist 104: 1609-1622. 

Allen, D.C. 1973. Fecundity of the saddled prominent, Heterocampa 

guttivitta. Annals of the Entomological Society of America 66: 

1181-1183. 

Grimble, D.G. and R.G. Newell. 1973. Damage to sugar maple in 

New York State from saddled prominent defoliation. Applied Forestry 

Research Institute Note No. 7. Syracuse, NY, Syracuse University: 4 p. 

Spear-O’Mara, J. and D.C. Allen. 2007. Monitoring populations of 

saddled prominent (Lepidoptera: Notodontidae) with pheromone-baited 

traps. Journal of Economic Entomology 100: 335-342. 

Articles

Web Links for Information 

on Saddled Prominent
600 Forest Pest Insects in North America:

166. Walnut Caterpillar, Datana integerrima Grote and Robinson 

(Lepidoptera: Notodontidae)

Orientation to Pest Walnut caterpillar, Datana integerrima Grote and Robinson, is a native 

North American notodontid whose larvae feed on walnut (Juglans), 

butternut (J. cinerea L.), pecan (Carya illinoinensis [Wangenh.] K. 

Koch), and hickory (C. tomentosa [Poir.] Nutt.). It is found in southern 

Ontario (Canada) and throughout the eastern United States. Adults fly 

in spring and summer and lay their eggs in masses on the undersides of 

the leaves of the host plants. The larvae feed gregariously until almost 

mature and are often seen in masses on the trunk and larger limbs, where 

they congregate to molt. Mature larvae drop to the ground and wander 

before pupating in the soil. There are one or two generations per year, 

depending on the location.

This caterpillar feeds on walnut (Juglans), butternut (J. cinerea), pecan 

(C. illinoinensis), and hickory (C. tomentosa). 

The walnut caterpillar is found in southern Ontario (Canada) and 

throughout the eastern United States. 

Hosts Commonly Attacked

Distribution

Images of 

Walnut Caterpillar

Figure 1. Adult of walnut caterpillar, Datana integerrima. (Jerry Armstrong, 

Bugwood.org)
A Photographic Guide 601

Images of Walnut 

Caterpillar (continued)

Figure 2. Eggs of walnut caterpillar. (Lacy L. Hyche, Auburn University, 

Bugwood.org)

Figure 3. Larvae (middle instars) of walnut caterpillar. (Lacy L. Hyche, Auburn 

University, Bugwood.org)

Figure 4. Larvae of walnut caterpillar feed in groups. (Jerry A. Payne, USDA 

Agricultural Research Service, Bugwood.org)
602 Forest Pest Insects in North America:

Images of Walnut 

Caterpillar (continued)

Figure 5. Walnut 

caterpillars aggregating 

on branch for molting. 

(Jerry A. Payne, USDA 

Agricultural Research 

Service, Bugwood.org)

Figure 6. Leaf skeletonizing by young larvae of walnut caterpillar. (Lacy L. Hyche, 

Auburn University, Bugwood.org)
A Photographic Guide 603

Images of Walnut 

Caterpillar (continued)

Figure 7. Complete 

defoliation of small tree 

by walnut caterpillar. 

(Lacy L. Hyche, 

Auburn University, 

Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

Known parasitoids of the walnut caterpillar include Telenomus 

ichthyurae Ashmead and Tetrastichus sp. in Texas.

http://www.na.fs.fed.us/spfo/pubs/fidls/walnutcat/walnutfidl.htm; USDA 

Forest Service, Pest and Disease Leaflet No. 41

http://www.ento.okstate.edu/ddd/insects/walnutdatana.htm; fact sheet of 

Oklahoma State University on biology and life cycle.

http://www.ag.auburn.edu/enpl//bulletins/walnutcaterpillar/

walnutcaterpillar.htm; fact sheet of Auburn University (Alabama, USA) 

on biology and control.

http://repository.tamu.edu/bitstream/handle/1969.1/87115/pdf_1558.

pdf?sequence=1; fact sheet of the Texas A&M University on biology 

and control.

Web Links for Information 

on Walnut Caterpillar
604 Forest Pest Insects in North America:

Tedders, W.L. and H.C. Ellis. 1977. Aerial application of Bacillus 

thuringiensis var. kurstaki (HD-1) to shade and ornamental pecan trees 

against Hyphantria cunea and Datana integerrima. Journal of the 

Georgia Entomological Society 12: 248-250.

Farris, M.E. 1978. Bionomics of the walnut caterpillar, Datana 

integerrima G. & R. Urbana, Il: University of Illinois, Dissertation. 

106 p. 

Farris, M.E. and J.E. Appleby. 1979. The walnut caterpillar, Datana 

integerrima G. & R. In: Anon. Walnut insects and diseases, workshop 

proceedings. General Technical Report NC-52. U.S. Department of 

Agriculture, Forest Service, North Central Forest Experiment Station, 

St. Paul, MN: 22-28. 

Articles on

Walnut Caterpillar
A Photographic Guide 605

167. Variable Oak Leaf Caterpillar, Lochmaeus manteo (Doubleday) 

(Lepidoptera: Notodontidae)

Orientation to Pest Variable oak leaf caterpillar, Lochmaeus manteo (Doubleday), is a native 

North American moth whose larvae feed on a wide variety of deciduous 

trees, especially oaks. The species is found across much of eastern North 

America. It overwinters as a prepupa in the soil and pupation occurs in 

early spring, with adult emergence following in May or June. Eggs are 

laid singly on the leaves of the host plant. The color pattern of larvae 

is variable. Young larvae skeletonize leaves, but older larvae eat entire 

leaves apart from the larger veins. There are two generations per year in 

the southern United States and one in the north. Outbreaks sometimes 

occur that defoliate large areas; however, tree mortality is usually very 

low. 

All species of oaks are attacked, but white oak (Quercus alba L.) is 

preferred. Other hosts include American beech (Fagus grandifolia

Ehrh.), American basswood (Tilia americana L.), paper birch (Betula 

papyrifera Marshall), American elm (Ulmus americana L.), walnut 

(Juglans), boxelder (Acer negundo L.), persimmon (Diospyros sp.), and 

apple (Malus).

The variable oak leaf caterpillar is found in a wide area in eastern North 

America, east of a line from western Ontario to eastern Texas.

Hosts Commonly Attacked

Distribution

Images of Variable

Oak Leaf Caterpillar

Figure 1. Adult of variable oak leaf caterpillar, Lochmaeus manteo. (USDA Forest 

Service - Northeastern Area Archive, USDA Forest Service, Bugwood.org)
606 Forest Pest Insects in North America:

Images of Variable

Oak Leaf Caterpillar

(continued)

Figure 2. Eggs of variable oak leaf caterpillar. (Ronald F. Billings, Texas Forest 

Service, Bugwood.org)

Figure 3. Young larvae of variable oak leaf caterpillar. (Ronald F. Billings, Texas 

Forest Service, Bugwood.org)

Figure 4. Mature larvae of the variable oak leaf caterpillar (color patterns vary). 

(Left: Gerald J. Lenhard, Lousiana State University, Bugwood.org; right: 

Scott Tunnock, USDA Forest Service, Bugwood.org)
A Photographic Guide 607

Images of Variable

Oak Leaf Caterpillar

(continued)

Figure 5. Pupae of variable oak leaf caterpillar. (USDA Forest Service - 

Northeastern Area Archive, USDA Forest Service, Bugwood.org)

Figure 6. Feeding damage of variable oak leaf caterpillar. (Ronald F. Billings, 

Texas Forest Service, Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

Among the nature enemies of this insect are egg parasitoids in the 

genera Trichogramma and Telenomus, which may kill 90 percent of 

the eggs. Nearly all egg masses have some parasitized eggs; only the 

eggs concealed within a cluster escape. This high level of parasitism 

and the failure of many prepupae to pupate in the spring, appear to be 

the major factors affecting population density. At least seven species 

of larval parasites attack variable oakleaf caterpillar larvae. The most 

important species are Diradops bethunei Cresson (Ichneumonidae), 

Protomicroplitus schizurae (Braconidae), and Lespesia schizurae

Sabrosky (Tachinidae), which collectively may kill up to 90 percent 

of the larvae.
608 Forest Pest Insects in North America:

Web Links for Information on

Variable Oak Leaf Caterpillar

http://www.fs.fed.us/r8/foresthealth/pubs/oakpests/p5.html; USDA Forest 

Service Southern Region fact sheet on biology and control.

http://www.maine.gov/doc/mfs/VariableOakLeafCaterpillar_new.htm; 

fact sheet of the Maine Forest Service on biology and control.

http://na.fs.fed.us/spfo/pubs/fidls/variableOLC/voc.htm; USDA Forest 

Service Forest Pest and Disease Leaflet No. 67.

Surgeoner, G.A. and W.E. Wallner. 1978. Foliage consumption by 

the variable oak leaf caterpillar, Heterocampa manteo (Lepidoptera: 

Notodontidae), its use in defoliation predictions. The Canadian 

Entomologist 110: 241-244. 

Articles
A Photographic Guide 609

168. Fall Webworm, Hyphantria cunea (Drury) (Lepidoptera: Arctiidae)

Orientation to Pest Fall webworm, Hyphantria cunea (Drury), is a native North American 

tiger moth, the larvae of which feed on the leaves of more than 100 

species of forest and shade trees. It is found in southern Canada and 

throughout the United States. Adults usually fly in late spring or early 

summer and lay masses of eggs on the undersides of leaves. In the 

southern United States, adults may be present from early spring through 

late summer. Larvae web foliage together and feed in groups inside 

a web, which is expanded as the larvae grow. Young larvae are upper 

surface skeletonizers, but older larvae consume the entire leaf except 

for the larger veins. Nearly mature larvae may feed alone outside the 

web. Larvae move to the ground when ready to pupate, where they spin 

a thin cocoon in the duff. Regional color variation exists in both adults 

and larvae. There are one to four generations per year, with multiple 

generations occurring at more southern latitudes. In its native range this 

insect has little impact on tree health as defoliation occurs late in the 

year, when most nutrients are in the roots. It is invasive in Eurasia, and 

there the level of damage appears to be greater.

Fall webworm feeds on a more than 100 species of deciduous forest 

or shade trees. Commonly defoliated plants include hickory (Carya 

tomentosa [Poir.] Nutt.), pecan (C. illinoinensis [Wangenh.] K. Koch), 

walnut (Juglans), elm (Ulmus), alder (Alnus), willow (Salix), mulberry 

(Morus), oak (Quercus), American sweetgum (Liquidambar styraciflua

L.), poplar (Populus) and numerous species of Rosaceae, e.g., cherry 

(Prunus), apple (Malus), and hawthorn (Crataegus). 

Fall webworm is found in southern Canada and throughout the United 

States.

Hosts Commonly Attacked

Distribution

Images of 

Fall Webworm

Figure 1. Adults of fall webworm, Hyphantria cunea, may be pure white or 

bear black spots. (Left: Jerry A. Payne, USDA Agricultural Research Service, 

Bugwood.org; right: Gerald J. Lenhard, Louiana State University, Bugwood.org)
610 Forest Pest Insects in North America:

Images of Fall

Webworm (continued)

Figure 2. Top, eggs 

of fall webworm near 

adult female; bottom, 

eggs with newly 

hatched larvae. 

(Top: Lacy L. Hyche, 

Auburn University, 

Bugwood.org; bottom: 

Ministry of Agriculture 

and Regional 

Development Archive, 

Ministry of 

Agriculture and 

Regional Development, 

Bugwood.org)

Figure 3. Left, young larvae of fall webworm; right, group of young larvae feeding. 

(Left: Milan Zubrik, Forest Research Institute - Slovakia, Bugwood.org; right: 

Lacy L. Hyche, Auburn University, Bugwood.org)
A Photographic Guide 611

Images of Fall

Webworm (continued)

Figure 4. Top, mature 

larvae of fall webworm; 

bottom, larva of orange 

race. (Top: James B. 

Hanson, USDA Forest 

Service, Bugwood.org; 

bottom: Lacy L. Hyche, 

Auburn University, 

Bugwood.org)

Figure 5. Pupa of fall 

webworm. (Ministry 

of Agriculture and 

Regional Development 

Archive, Ministry of 

Agriculture and Regional 

Development, 

Bugwood.org)

Figure 6. Close up of 

feeding of fall webworm. 

(Milan Zubrik, Forest 

Research Institute - 

Slovakia, Bugwood.org)
612 Forest Pest Insects in North America:

Images of Fall

Webworm (continued)

Figure 7. Feeding and 

webs of fall webworm. 

(Top: Clemson 

University - USDA 

Cooperative Extension 

Slide Series, 

Bugwood.org; bottom: 

Steven Katovich, 

USDA Forest Service, 

Bugwood.org)
A Photographic Guide 613

Important Biological Control 

Agents Related to this 

Pest Species

Many different species of parasitoids are associated with the larvae and 

pupae of this species in different locations.

http://ohioline.osu.edu/hyg-fact/2000/2026.html; fact sheet of Ohio State 

University on biology and control. 

http://ento.psu.edu/extension/factsheets/fall-webworm; fact sheet of 

Pennsylvania State University. 

http://www.ag.auburn.edu/enpl/bulletins/fallwebworm/fallwebworm.htm; 

fact sheet of Auburn University (Alabama, USA).

http://www.umassgreeninfo.org/fact_sheets/defoliators/fall_webworm.

html; fact sheet of the University of Massachusetts.

http://www.oregon.gov/ODF/privateforests/docs/fh/FallWebworm.

pdf?ga=t; fact sheet of the Oregon Department of Forestry.

http://edis.ifas.ufl.edu/in878; extension publication of the University of 

Florida. 

Morris, R.F. 1963. Synonymy and color variation in the fall webworm, 

Hyphantria cunea Drury (Lepidoptera: Arctiidae). The Canadian 

Entomologist 95: 1217-1223. 

Oliver, A.D. 1964. Studies on the biological control of the fall webworm, 

Hyphantria cunea, in Louisiana. Journal of Economic Entomology 57: 

314-318. 

Warren, L.O. and M. Tadic. 1970. The fall webworm, Hyphantria cunea

(Drury). Arkansas Agricultural Experiment Station Bulletin No. 759: 

106 p. 

Yang, Z.Q., J.R. Wei, and X.Y. Wang. 2006. Mass rearing and 

augmentative releases of the native parasitoid Chouioia cunea for 

biological control of the introduced fall webworm Hyphantria cunea in 

China. BioControl 51: 401-418.

Wang, Y., F.Q. Goo, Z. Xu, X. Chen, K. Li, Y.F. Xiao, S.H. Sun, and 

J.Y. Qi. 2010. Parasitoids and mortality of the overwintering pupal 

stage of Hyphantria cunea (Drury). Journal of Shenyang Agricultural 

University 41(6): 686-689.

Web Links for Information 

on Fall Webworm

Articles
614 Forest Pest Insects in North America:

169. Arborvitae Leafminer, Argyresthia thuiella (Packard) (Lepidoptera: 

Argresthiidae)

Orientation to Pest The arborvitae leafminer, Argyresthia thuiella (Packard), is a native 

North American moth that forms mines in foliage of eastern arborvitae 

(northern white cedar) trees (Thuja occidentalis L.) in forests and 

landscapes. This moth is found in eastern Canada and in the United 

States, south to Maryland and west to Missouri. It is also invasive in 

Europe. Adults fly in spring to early summer and adults lay eggs in the 

axils of branchlets or along the edges of leaves. Newly emerged larvae 

bore into the leaves and feed the rest of the year there as leafminers. 

Winter is passed as larvae in mines and pupation occurs in the mine. 

Adults emerge the following spring. Outbreaks in Maine have severely 

damaged arborvitae. Damage can also occur in nurseries or on landscape 

arborvitae. 

This caterpillar feeds on eastern arborvitae (northern white cedar) trees 

(T. occidentalis).

The moth is found in eastern Canada and in the United States, south to 

Maryland and west to Missouri.

Hosts Commonly Attacked

Distribution

Images of 

Arborvitae Leafminer

Figure 1. Adult of 

arborvitae leafminer, 

Argyresthia thuiella

(moth wingspan is 

8 mm); bottom, moth 

in natural pose. 

(Top: Petr Kapitola, 

State Phytosanitary 

Administration, 

Bugwood.org; bottom: 

Tom Murray)
A Photographic Guide 615

Images of Arborvitae 

Leafminer (continued)

Figure 2. Mature larvae of arborvitae leafminer, removed from mine. (John A. 

Weidhass, Virginia Polytechnic Institute and State University, Bugwood.org)

Figure 3. Top, mined 

(brown) arborvitae 

foliage; bottom, view 

of larvae in mine (cut 

away). (Top: Connecticut 

Agricultural Experiment 

Station Archive, 

Connecticut Agricultural 

Experiment Station, 

Bugwood.org; bottom: 

Robert Childs, University 

of Massachusetts, 

Bugwood.org)
616 Forest Pest Insects in North America:

Images of Arborvitae 

Leafminer (continued)

Figure 4. Arborvitae leafminer pupa. (John A. Weidhass, Virginia Polytechnic 

Institute and State University, Bugwood.org)

Figure 5. View of 

damage on landscape 

arborvitae; top, close 

up; bottom, general 

view of damaged plant. 

(Both photos: Robert 

Childs, University 

of Massachusetts, 

Bugwood.org)

In Canada, natural control of arborvitae leafminers is provided by the 

widespread parasitoid Pentacnemus bucculatricis Howard and also by 

Apanteles bedelliae Viereck. Some 26 species of parasitoids are known 

to attack this leafminer.

Important Biological Control 

Agents Related to this 

Pest Species
A Photographic Guide 617

Web Links for Information 

on Arborvitae Leafminer

http://www.umassgreeninfo.org/fact_sheets/leaf_miners/arborvitae_

leafminer.html; fact sheet of the University of Massachusetts on biology 

and control.

http://www.entomology.umn.edu/cues/Web/064ArborvitaeLeafminer.pdf; 

fact sheet of the University of Minnesota on biology and control.

http://ccesuffolk.org/assets/Horticulture-Leaflets/Arborvitae-Leafminer.

pdf; fact sheet of Cornell Extension.

Kurir, A. 1983. On the dispersal and biology of the North American 

arborvitae leafminer, Argyresthia thuiella Packard (Lep., Argyresthiidae) 

in Austria. Anzeiger für Schädlingskunde Pflanzenschutz Umweltschutz

56(7): 125-128. (In German). 

Anon. 1983. Cedar leafminers. Argyresthia spp. Insect Identification 

Sheet, Agriculture Canada (74): 2 p.

Articles
618 Forest Pest Insects in North America:

170. Pine Needle Sheathminer, Zelleria haimbachi Busck (Lepidoptera: 

Yponomeutidae)

Orientation to Pest Pine needle sheathminer, Zelleria haimbachi Busck, is a native North 

American moth that feeds on needles of jack pine (Pinus banksiana

Lamb.) in Ontario (Canada) and the Great Lakes region of the United 

States, and on ponderosa (P. ponderosa P. & C. Lawson) and lodgepole 

(P. contorta Douglas) in western North America north of Mexico. Larvae 

create loose silken tunnels next to the bark of first-year shoots, from 

where they bore through the sheaths and eat the needle bases. Needles 

die and turn tan, and are loosely held in the sheath. Dead needles easily 

slip out of the sheaths with a gentle pull. Larvae escape disturbance by 

wriggling backwards and falling off the shoot, to hang suspended by a 

strand of silk.

This caterpillar feeds on jack (P. banksiana), lodgepole (P. contorta), and 

ponderosa pine (P. ponderosa). 

The moth is found in Ontario (Canada), the Great Lakes region of the 

United States, California, and other parts of the western United States. 

Images of 

Pine Needle Sheathminer

Figure 1. Adult of pine 

needle sheathminer, 

Zelleria haimbachi. 

(Chris Grinter)

Figure 2. Oviposition 

scar in needles where 

eggs have been 

deposited. (Donald 

Owen, California 

Department of Forestry 

and Fire Protection, 

Bugwood.org)

Hosts Commonly Attacked

Distribution
A Photographic Guide 619

Images of Pine Needle 

Sheathminer (continued)

Figure 3. Young larvae of pine needle sheathminer, in its sheath feeding stage. 

(Donald Owen, California Department of Forestry and Fire Protection, 

Bugwood.org)

Figure 4. Mature larvae of pine needle sheathminer. (Left: Connecticut 

Agricultural Experiment Station Archive, Connecticut Agricultural Experiment 

Station, Bugwood.org; right: Donald Owen, California Department of Forestry 

and Fire Protection, Bugwood.org)

Figure 5. Pupae of pine needle sheathminer (left), also showing close up of 

webbing and frass associated with feeding; feeding damage seen from a 

distance (right) on ponderosa pine. (Left: Scott Tunnock, USDA Forest Service, 

Bugwood.org; right: Ward Strong, BC Ministry of Forests, Bugwood.org)
620 Forest Pest Insects in North America:

Important Biological Control 

Agents Related to this 

Pest Species

No information on natural enemies of this species was found.

None

Stevens, H.E. 1959. Biology and control of the pine needle-sheath miner, 

Zelleria haimbachi Busck (Lepidoptera; Hyponomeutidae). Pacific 

Southwest Forest and Range Experiment Station: 20 p.

Web Links for Information 

on Pine Needle Sheathminer

Articles
A Photographic Guide 621

171. Pine Butterfly, Neophasia menapia (Felder and Felder) (Lepidoptera: 

Pieridae)

Orientation to Pest The pine butterfly, Neophasia menapia (Felder and Felder), is a native 

North American butterfly that is an important pest of ponderosa pine 

(Pinus ponderosa P. & C. Lawson) in the western United States, where 

large outbreaks have occurred. Adults fly in late summer and fall, and 

eggs are laid in rows in groups of 5-20 on current year needles. Eggs 

overwinter and hatch the following June, or about the time that new 

needles begin to appear on ponderosa pine. Young larvae eat the old 

needles first, but new needles are eaten later by older larvae. Larvae 

attach themselves to needles, twigs, bark, or other objects before 

pupating. In 2 to 3 weeks, adults emerge and complete the cycle. There 

is one generation per year. Older trees are more susceptible to injury than 

younger thriftier trees. Outbreaks usually last 3 or 4 years; most cause 

little mortality, although intense and widespread outbreaks may result in 

reduction in tree growth. A few outbreaks have killed extensive stands of 

older trees when aided by bark beetles. 

In most areas, this caterpillar feeds mainly on ponderosa pine (P. 

ponderosa), but during outbreaks other conifers may also be attacked if 

intermixed with ponderosa pine, such as lodgepole (P. contorta Douglas) 

and western white (P. monticola Douglas ex D. Don) pines, Douglas-fir 

(Pseudotsuga menziesii [Mirb.] Franco), grand fir (Abies grandis [Dougl. 

ex D. Don] Lindl.), and western larch (Larix occidentalis Nutt.). In 

the coastal area of northwestern Washington and on Vancouver Island, 

British Columbia, Canada, outbreaks have occurred in Douglas-fir 

stands.

The butterfly is found throughout the western United States; but 

outbreaks have occurred primarily in Oregon, Washington, Idaho, 

Montana, and British Columbia. 

Hosts Commonly Attacked

Distribution

Images of 

Pine Butterfly

Figure 1. Adult female (left) and male (right) of pine butterfly, Neophasia 

menapia. (Left: Ladd Livingston, Idaho Department of Lands, Bugwood.org; 

right: Terry Spivey, USDA Forest Service, Bugwood.org)
622 Forest Pest Insects in North America:

Images of Pine Butterfly

(continued)

Figure 2. Eggs of pine butterfly. (USDA Forest Service - Ogden Archive, USDA 

Forest Service, Bugwood.org)

Figure 3. Young larvae of pine butterfly. (Left: Scott Tunnock, USDA Forest 

Service, Bugwood.org; right: USDA Forest Service - Ogden Archive, USDA 

Forest Service, Bugwood.org)
A Photographic Guide 623

Images of Pine Butterfly

(continued)

Figure 4. Mature larva 

of pine butterfly. (Ladd 

Livingston, Idaho 

Department of Lands, 

Bugwood.org)

Figure 5. Pupa of pine 

butterfly. (Jerald E. 

Dewey, USDA Forest 

Service, Bugwood.org)
624 Forest Pest Insects in North America:

Images of Pine Butterfly

(continued)

Figure 6. Feeding damage of pine butterfly on ponderosa pines. (USDA Forest 

Service - Ogden Archive, USDA Forest Service, Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

Several insects, including hemipterans (Podisus spp. and Apoecilus spp.), 

snakeflies (Raphidia spp.), sarcophagid flies (Agria spp.), and wasps 

(Ichneumonidae) have been reported preying on different stages of pine 

butterfly. Decline of the 1922-23 outbreak of this butterfly was attributed 

to mortality from some of these natural enemies, especially a native 

ichneumon parasite, Theronia atalantae (Poda). 

http://butterfly.ucdavis.edu/butterfly/Neophasia/menapia; website on this 

insect from a natural history point of view.

http://imfc.cfl.scf.rncan.gc.ca/insecte-insect-eng.asp?geID=1000029&

ind=P; fact sheet of Natural Resource Canada on biology and phenology.

http://extension.oregonstate.edu/mwm/w10fhmbutterfly; extension note 

of Oregon State University.

Evenden, J.C. 1926. The pine butterfly, Neophasia menapia Felder. 

Journal of Agricultural Research 33(4): 339-344.

Evenden, J.C. 1940. Effects of defoliation by the pine butterfly upon 

ponderosa pine. Journal of Forestry 38(12): 949-955.

Cole, W.E. 1966. Effect of pine butterfly defoliation on ponderosa pine in 

southern Idaho. Research Note INT-46. Ogden, UT: U.S. Department of 

Agriculture, Forest Service, Intermountain Forest and Range Experiment 

Station: 7 p.

Young, R.M. 1986. Mass emergences of the pine white, Neophasia 

menapia menapia (Felder & Felder), in Colorado (Pieridae). Journal of 

the Lepidopterists’ Society 40 (4): 314. 

Web Links for Information 

on Pine Butterfly

Articles
A Photographic Guide 625

172. Balsam Gall Midge, Paradiplosis tumifex Gagné (Diptera: 

Cecidomyiidae)

Orientation to Pest Balsam gall midge, Paradiplosis tumifex Gagné, is a native North 

American cecidomyiid fly that galls needles of balsam (Abies balsamea

[L.] Miller) and Fraser fir (A. fraseri [Pursh] Poir.). In older literature, 

these galls were mistakenly attributed to another species, Dasineura 

balsamicola (Lintner), which is an inquiline that invades the galls of 

P. tumifex, killing it and feeding on the gall tissue. Paradiplosis tumifex

has a wide distribution, being found throughout the ranges of its two 

main hosts. The gall midge overwinters as a larva in the soil under an 

infested host tree. Pupation takes place in spring, and adult emergence 

occurs shortly thereafter. Eggs are laid in developing needles, and larval 

feeding causes quick development of gall tissue in immature needles. 

In late fall, larvae leave the galls and drop to the ground for the winter. 

There is one generation per year. Galling is of concern only in Christmas 

tree plantations, not forests. 

This gall midge attacks needles of balsam fir (A. balsamea) and Fraser fir 

(A. fraseri).

This species is found throughout the ranges of balsam and Fraser 

firs, being much of southeastern Canada and adjacent areas of the 

northeastern United States (range of balsam fir), plus the sky islands of 

the southern Appalachian Mountains (range of Fraser fir). 

Hosts Commonly Attacked

Distribution

Images of 

Balsam Gall Midge

Figure 1. Adult balsam gall midge, Paradiplosis tumifex. (Ronald S. Kelley, 

Vermont Department of Forests, Parks and Recreation, Bugwood.org)
626 Forest Pest Insects in North America:

Images of Balsam 

Gall Midge (continued)

Figure 2. Balsam gall midge galls on balsam fir. (Ronald S. Kelley, Vermont 

Department of Forests, Parks and Recreation, Bugwood.org)

Figure 3. Larvae of 

the balsam gall midge 

exposed by opening the 

gall. (Thérèse Arcand 

- Natural Resources 

Canada, Canadian 

Forest Service)

Important Biological Control 

Agents Related to this 

Pest Species

Parasitoids of this gall maker include the encyrtids Pseudoencyrtus 

borealis MacGown, Tetrastichus cecidivorus MacGowan, Tetrastichus 

marcovitchi (Crawford), Tetrastichus whitmani (Firault), and the 

platygasterids Platygaster abicollis MacGown and Osgood and 

Playtgaster mainensis MacGown and Osgood.

http://imfc.cfl.scf.rncan.gc.ca/insecte-insect-eng.asp?geID=3708; fact 

sheet of Natural Resources Canada on biology and phenology.

http://www.maine.gov/doc/mfs/balsgalmid.htm; fact sheet of the state 

of Maine.

http://extension.unh.edu/resources/files/Resource000986_Rep2348.pdf; 

highly detailed power point presentation on biology and control of this 

gall maker.

Web Links for Information 

on Balsam Gall Midge
A Photographic Guide 627

Osgood, E.A. and R.J. Gagné. 1978. Biology and taxonomy of two 

gall midges (Diptera : Cecidomyiidae) found in galls on balsam fir 

needles with description of a new species of Paradiplosis. Annals of the 

Entomological Society of America 71: 85-91.

West, R.J. and J.D. Shorthouse. 1982. Morphology of the balsam 

fir needle gall induced by the midge Paradiplosis tumifex (Diptera: 

Cecidomyiidae). Canadian Journal of Botany 60: 131-140.

Räther, M. and N.J. Mills. 1989. Possibilities for the biological control 

of the Christmas tree pests, the balsam gall midge, Paradiplosis tumifex

Gagné (Diptera: Cecidomyiidae) and the balsam twig aphid, Mindarus 

abietinus Koch (Homoptera: Mindaridae), using exotic enemies from 

Europe. Biocontrol News and Information 10(2): 119-129.

Osgood, E.A., R.L. Bradbury, and F.A. Drummond. 1992. The balsam 

gall midge - an economic pest of balsam fir Christmas trees. Maine 

Agricultural Experiment Station Technical Bulletin No. 151: 30 p. 

(Available at http://library.umaine.edu/maineaes/technicalbulletin/tb151.

pdf).

Articles
628 Forest Pest Insects in North America:

173. Poplar Leafcurl Midge, Prodiplosis morrisi Gagné (Diptera: 

Cecidomyiidae)

Orientation to Pest The poplar leafcurl midge, Prodiplosis morrisi Gagné, is a native North 

American cecidomyiid fly that lays its eggs on developing cottonwood 

terminals. The larvae feed on surfaces of expanding leaves, causing 

them to curl into elongated, largely cylindrical shapes. Leaves may stay 

green with only curled edges turning brown, or leaf may be killed. With 

sufficient feeding, terminal shoots may become stunted or killed. Trees 

of all sizes may be attacked. There may be up to five or more generations 

per year. Each generation damages 1 to 2 whorls of leaves, and because 

there is a short period between generations, normal leaves alternate 

with damaged leaves. The many larvae that develop in each curled leaf 

drop to the soil beneath the tree to pupate. Larvae of the last generation 

overwinter in the soil. 

This midge attacks various species of Populus, including eastern 

cottonwood (P. deltoides W. Bartram ex Humphry Marshall), quaking 

aspen (P. tremuloides Michx.), and Populus hybrids.

This species is of greatest importance in the southern United States, in 

cottonwood plantations. 

Images of 

Poplar Leafcurl Midge

Figure 1. Injury to 

cottonwood seedling 

from poplar leafcurl 

midge, Prodiplosis 

morrisi. (James 

Solomon, USDA Forest 

Service, Bugwood.org)

Hosts Commonly Attacked

Distribution
A Photographic Guide 629

Important Biological Control 

Agents Related to this 

Pest Species

No information is available on natural enemies of this species.

http://wiki.bugwood.org/Archive:Poplar/Prodiplosis_morrisi; Bugwood 

Wiki fact sheet on biology.

Gagné, R.J. 1966. A new species of Prodiplosis (Diptera: Cecidomyiidae) 

found in leaf curls on Populus deltoides. Annals of the Entomological 

Society of America 59: 1154-1157.

Gagné, R.J. 1989. The Plant-feeding Gall Midges of North America. 

Cornell University Press. Ithaca, New York: 340 p.

Ostry, M.E., L.F. Wilson, H.S. McNabb, Jr., and L.M. Moore. 1988. 

A Guide to Insect, Disease, and Animal Pests of Poplars. Agricultural 

Handbook No. 677. U.S. Department of Agriculture, Washington, DC: 

118 p.

Skuhravý, V., M. Skuhravá and J.W. Brewer. 1997. Gall midges (Dipt., 

Cecidomyiidae) associated with Populus tremula, P. tremuloides and 

their hybrid (Salicaceae). Journal of Applied Entomology 121: 315-320.

Web Links for Information 

on Poplar Leafcurl Midge

Articles
630 Forest Pest Insects in North America:

174. Douglas-fir Needle Midge, Contarinia pseudotsugae Condrashoff 

(Diptera: Cecidomyiidae)

Orientation to Pest Douglas-fir needle midge, Contarinia pseudotsugae Condrashoff, is one 

of three species in this genus of native North American cecidomyiid flies 

that lay their eggs in developing needles of Douglas-fir (Pseudotsuga 

menziesii [Mirb.] Franco). This is the most abundant of the three. It is 

a significant pest of Douglas-fir when it is grown as Christmas trees, 

particularly in the dry-belt of open-grown interior forests in the Pacific 

northwestern United States in California, Oregon, Washington, Idaho, 

Montana, and in British Columbia, Canada. Adults emerge from the soil 

in spring and lay eggs on needles. The larvae bore into needles to feed, 

causing their growth to be deformed. In the fall, mature larvae drop back 

into the soil to pupate and overwinter. Damaged needles bear small galls 

and heavily galled Christmas trees have lower market value. There is one 

generation of this fly per year.

The only known host of this insect is Douglas-fir (P. menziesii).

This species is of concern in the Pacific northwestern United States 

(California, Oregon, Washington, Idaho, and Montana) and British 

Columbia, Canada, but is also found in Pennsylvania. 

Hosts Commonly Attacked

Distribution

Images of Douglas-fir

Needle Midge

Figure 1. Adult of Douglas-fir needle midge, Contarinia pseudotsugae. (USDA 

Forest Service Archive, USDA Forest Service, Bugwood.org)
A Photographic Guide 631

Images of Douglas-fir

Needle Midge (continued)

Figure 2. Larva of 

Douglas-fir needle 

midge inside its gall, 

which has been cut 

open. (Ward Strong, 

BC Ministry of Forests, 

Bugwood.org)

Figure 3. Douglasfir needles (top) 

showing injury due 

to Douglas-fir needle 

midge; and, bottom, 

damage in an earlier 

stage. (Top: Elizabeth 

Willhite, USDA Forest 

Service, Bugwood.

org; bottom: Rayanne 

Lehman, Pennsylvania 

Department of 

Agriculture, 

Bugwood.org)

Figure 4. Damage to Douglas-fir from Douglas-fir needle midge. (Left: USDA

Forest Service Archive, USDA Forest Service, Bugwood.org; right: Ward Strong, 

BC Ministry of Forests, Bugwood.org)
632 Forest Pest Insects in North America:

Important Biological Control 

Agents Related to this 

Pest Species

No information is available on natural enemies of this species.

http://extension.psu.edu/ipm/program/christmas-tree/pest-factsheets/needle-discoloration-and-injury/Douglas-fir.pdf; fact sheet of 

Pennsylvania State University on biology and control.

http://oregonstate.edu/dept/nurserystartup/onnpdf/onn060108.pdf; fact 

sheet of Oregon State University, helpful in determining a spray schedule 

for this pest.

http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5187407.

pdf; fact sheet of the USDA FS Forest Health Protection unit on 

recognition and biology. 

Condrashoff, S.F. 1961. Three new species of Contarinia (Diptera: 

Cecidomyiidae) in Douglas-fir needles. The Canadian Entomologist

93(2): 123-130. 

Condrashoff, S.F. 1962. Bionomics of three closely related species of 

Contarinia Cond. (Diptera: Cecidomyiidae) from Douglas-fir needles. 

The Canadian Entomologist 94: 376-394. 

Web Links for Information 

on Douglas-fir Needle Midge

Articles
A Photographic Guide 633

175. Pine False Webworm, Acantholyda erythrocephala (L.) (Hymenoptera: 

Pamphiliidae)

Orientation to Pest Pine false webworm, Acantholyda erythrocephala (L.), is an introduced 

pamphiliid sawfly of European origin that is now present in several 

parts of eastern North America and Canada. It feeds on several pines. 

Winter is passed as prepupae, which pupate in the spring. Adults emerge 

soon after and lay eggs in short rows of 3 to 10 eggs in small slits cut 

into last year’s needles. Young larvae spin loose webs in which they 

feed gregariously on old needles, which they cut off and then pull into 

the web to eat. Older larvae are solitary and feed from silken tubes 

bound to twigs. Frass and bits of needles stick to these silk tubes. When 

mature, larvae drop to the ground, build earthen cells, and overwinter as 

prepupae. Heavy infestations can defoliate hosts and cause tree mortality.

This sawfly feeds especially on eastern white (Pinus strobus L.) and red 

(P. resinosa Sol. ex Aiton), but also Scotch (P. sylvestris L.), Austrian 

(P. nigra J. F. Arnold), and Japanese red (P. densiflora Siebold & Zucc.) 

pines.

This sawfly is found in New England, New York, New Jersey, 

Pennsylvania, Wisconsin, Minnesota, Newfoundland, Alberta, Quebec, 

and Ontario. 

Hosts Commonly Attacked

Distribution

Images of Pine 

False Webworm

Figure 1. Top, adult 

male (right) and female 

(left) of pine false 

webworm, Acantholyda 

erythrocephala, in 

copula; and, bottom, 

adult female ovipositing 

on red pine foliage. 

(Both photos: Barry 

Lyons, Canadian Forest 

Service, Bugwood.org) 
634 Forest Pest Insects in North America:

Images of Pine 

False Webworm 

(continued)

Figure 2. Eggs of pine false webworm on red pine foliage. (Barry Lyons, 

Canadian Forest Service, Bugwood.org)

Figure 3. Top, neonate larva of pine false webworm emerging from the egg; 

and bottom, ultimate instar larva climbing on silk strands outside the web. (Both 

photos: Barry Lyons, Canadian Forest Service, Bugwood.org)
A Photographic Guide 635

Images of Pine 

False Webworm 

(continued)

Figure 4. Damage 

(shoots with clipped off 

needles) by pine false 

webworm on young 

plantation-grown red 

pine. (Barry Lyons, 

Canadian Forest 

Service, Bugwood.org)

Figure 5. Defoliation in pine plantations in Simcoe Co., Ontario, due to pine false 

webworm. (Barry Lyons, Canadian Forest Service, Bugwood.org)
636 Forest Pest Insects in North America:

Important Biological Control 

Agents Related to this 

Pest Species

Since this is an invasive species in North America, the parasitoids from 

its native range in Europe have been investigated for introduction. The 

most important such species is the tachinid Myxexoristops hertingi

Mesnil, which has been released in Ontario, Canada. 

http://bugs.osu.edu/bugdoc/Shetlar/factsheet/christmasstree/pine_false_

webworm.htm; fact sheet of Ohio State University on biology and 

control of pine false webworm for Christmas tree growers.

http://www.dec.ny.gov/docs/lands_forests_pdf/pfw.pdf; article 

concerning importance of pine false webworm in New York.

http://imfc.cfl.scf.rncan.gc.ca/insecte-insect-eng.asp?geID=1000130; 

fact sheet of Natural Resources Canada.

Lyons, D.B. 1995. Pine false webworm, Acantholyda erythrocephala. In: 

Armstrong, J.A. and W.G.H. Ives (eds.). Forest Insect Pests in Canada. 

Natural Resources Canada, Canadian Forest Service, Ottawa: 245-251.

Kessel, C. 1998. The impact of the pine false webworm on the 

Ontario Christmas tree industry. In: Lyons, D.B., G.C. Jones, and T.A. 

Scarr (eds.). Proceedings of a workshop on the pine false webworm, 

Acantholyda erythrocephala (Hymenoptera: Pamphiliidae). University 

of Toronto, Toronto, Ontario, Canada, 16 February 1998.

Asaro, C. and D.C. Allen. 2001. History of a pine false webworm 

(Hymenoptera: Pamphiliidae) outbreak in northern New York. Canadian 

Journal of Forest Research 31: 181-185.

Kenis, M. and K. Kloosterman. 2001. European parasitoids of the pine 

false webworm (Acantholyda erythrocephala [L.]) and their potential for 

biological control in North America. In: Liebhold, A.M., M.L. McManus, 

I.S. Otvos, S.L.C. Fosbroke (eds.). Proceedings of a conference entitled 

“Integrated management and dynamics of forest defoliating insects” held 

1999 August 15-19, Victoria, British Columbia, and published as General 

Technical Report NE-277. U.S. Department of Agriculture, Forest 

Service, Northeastern Research Station, Newtown Square, Pennsylvania, 

USA: 65-73. (Available at http://iufro-archive.boku.ac.at/wu70307/

victoria/kenis.pdf).

Lyons, D.B., M. Kenis, and R.S. Bourchier. 2002. Acantholyda 

erythrocephala (L.), pine false webworm (Hymenoptera: Pamphiliidae ). 

In: Mason, P.G. and J.T. Huber (eds.). Biological Control Programmes in 

Canada, 1981-2000. CABI, Wallingford, UK: 22-28. 

Articles

Web Links for Information 

on Pine False Webworm
A Photographic Guide 637

176. Redheaded Pine Sawfly, Neodiprion lecontei (Fitch) (Hymenoptera: 

Diprionidae)

Orientation to Pest Redheaded pine sawfly, Neodiprion lecontei (Fitch), is a native North 

American sawfly that defoliates various pines. Conifers in other genera 

may also be fed on when they grow intermixed with preferred species. 

This sawfly is found in southeastern Canada and throughout the eastern 

United States. It overwinters as a prepupa in the soil. Pupation occurs 

in spring and adults emerge soon after. Eggs are inserted in needles of 

either the current or previous year’s growth. A single female may lay up 

to 150 eggs. The larvae feed gregariously on either old or new needles, 

or even bark of tender twigs. Young larvae partially consume needles 

and cause them to dry out and curl, giving a straw-like appearance. 

Older larvae may consume entire needles. In some cases, trees may be 

completely defoliated. To prepare for winter, mature larvae drop from the 

foliage to the ground, where they spin a cocoon and molt to the pre-pupal 

stage. There are three generations per year in the southern United States 

but only one in the northern part of the United States and in Canada. 

This is one of the most damaging sawflies in North America. Trees at 

greatest risk are stressed trees growing on shallow soils, very wet or 

dry sites, or ones where trees are experiencing severe competition from 

other vegetation. Reducing vegetative competition, avoiding planting 

on poor sites, and using tight spacing to encourage early canopy closure 

are recommended to reduce damage from this sawfly to pines grown in 

plantations.

The main hosts of redheaded pine sawfly are jack (Pinus banksiana

Lambert), red (P. resinosa Sol. ex Aiton), shortleaf (P. echinata Mill.), 

loblolly (P. taeda L.), slash (P. elliottii Engelm.), longleaf (P. palustris

Mill.), and pitch (P. rigida Mill.) pines.

This sawfly is found in southeastern Canada and throughout the eastern 

United States.

Hosts Commonly Attacked

Distribution

Images of Redheaded

Pine Sawfly

Figure 1. Adult 

redheaded pine sawfly, 

Neodiprion leconte. 

(Lacy L. Hyche, 

Auburn University, 

Bugwood.org)
638 Forest Pest Insects in North America:

Images of Redheaded

Pine Sawfly (continued)

Figure 2. Eggs of 

redheaded pine sawfly 

being laid (top) and, 

bottom, close up of 

eggs in pine needle. 

(Top: James McGraw, 

North Carolina State 

University, Bugwood.org; 

bottom: Lacy L. Hyche, 

Auburn University, 

Bugwood.org)

Figure 3. Larvae of redheaded pine sawfly; left, close up of two, and right, 

a large aggregation of feeding larvae. (Left: Gerald J. Lenhard, Louisiana 

State University, Bugwood.org; right: Clemson University - USDA Cooperative 

Extension Slide Series, Bugwood.org)

Figure 4. Cocoons of 

redheaded pine sawfly. 

(Lacy L. Hyche, Auburn 

University, Bugwood.org)
A Photographic Guide 639

Images of Redheaded

Pine Sawfly (continued)

Figure 5. Characteristic 

“straw” damage caused 

by redheaded pine 

sawfly larvae. (G. Keith 

Douce, University of 

Georgia, Bugwood.org)

Figure 6. Damage (branches with clipped off needles) to longleaf pines by 

redheaded pine sawfly. (Andrew J. Boone, South Carolina Forestry Commission, 

Bugwood.org)
640 Forest Pest Insects in North America:

Important Biological Control 

Agents Related to this 

Pest Species

Important natural enemies of this sawfly include a nuclear polyhedrosis 

virus that has been developed in Canada as a biopesticide, the egg 

parasitoid Closterocerus cinctipennis Ashmead, and tachinid larval 

parasitoids in the genus Spathimeigenia.

http://www.forestpests.org/vermont/redheadsawfly.html; fact sheet of the 

Vermont Department of Forests, Parks, and Recreation on biology and 

control.

http://edis.ifas.ufl.edu/in882; fact sheet of the University of Florida on 

biology and control. 

http://pubs.ext.vt.edu/3006/3006-1453/3006-1453_pdf.pdf; fact sheet of 

the Virginia Tech extension on biology and control. 

http://ohioline.osu.edu/hyg-fact/2000/2554.html; fact sheet of Ohio State 

University extension on biology and control.

Benjamin, D.M. 1955. The biology and ecology of the redheaded pine 

sawfly. USDA Forest Service Technical Bulletin No. 1118: 57 p.

Drooz, A.T., R.C. Wilkinson, and V.H. Fedde. 1977. Larval and cocoon 

parasites of three Neodiprion sawflies in Florida. Environmental 

Entomology 6: 60-62.

Cunningham, J.C., P. DeGroot, and J.R. McPhee. 1984. Lecontvirus: 

a viral insecticide for control of redheaded pine sawfly, Neodiprion 

lecontei. Technical Note No. 2, Forest Pest Management Institute, 

Canada: 5 p.

Hyche, L.L. 1992.The redheaded pine sawfly (Neodiprion lecontei): 

a guide to recognition and habits. Bulletin No. 617 of the Alabama 

Agricultural Experiment Station. Auburn University, Auburn, Alabama: 

11 p.

Wilson, L.F., R.C. Wilkinson, Jr., and R.C. Averill. 1992. Redheaded pine 

sawfly - its ecology and management. USDA Forest Service Handbook 

No. 694: 54 p.

Web Links for Information 

on Redheaded Pine Sawfly

Articles
A Photographic Guide 641

177. Swaine Jack Pine Sawfly, Neodiprion swainei (Middleton) 

(Hymenoptera: Diprionidae)

Orientation to Pest Swaine jack pine sawfly, Neodiprion swainei (Middleton), is a native 

North American sawfly. It is considered to be the most important sawfly 

pest of pines in eastern Canada. Its preferred host is jack pine (Pinus 

banksiana Lambert), but other species of pines will also be defoliated 

if they grow near an outbreak of this sawfly on jack pine. This sawfly 

is found in the Great Lakes states of the United States and throughout 

most of the range of jack pine in Canada (from Nova Scotia west to 

Alberta). Outbreaks, though, have only been recorded in Ontario and 

Quebec. Swaine jack pine sawfly overwinters as a prepupa in cocoons 

in the litter or topsoil. Pupation occurs in spring and adults emerge 

soon after. In June or July, females lay one to three eggs per needle in 

the current year’s growth. The larvae feed gregariously on old needles, 

usually on trees in exposed locations. Mature larvae drop from foliage to 

the ground, where they spin a cocoon in the duff and molt to the prepupa, the overwintering stage. There is one generation per year. Many 

outbreaks of this sawfly occurred in Ontario and Quebec up until the 

1960s, usually at about 8 year intervals, on poor sites (for jack pine) on 

outwash plains. The last significant defoliation (in Canada) occurred 

over 440 ha in Quebec in 1994. In stands of mature trees, most trees may 

either be killed or, if they survive, will be stag-headed (killed on top). In 

the Great Lakes states (in the United States), outbreaks have occurred 

mainly in plantations or windbreaks. A nuclear polyhedrosis virus that 

is specific to this sawfly was discovered in the 1960s and developed 

as a potential biopesticide. It provided effective control but was never 

developed as a commercial pesticide. 

The main host of the Swaine jack pine sawfly is jack pine (P. banksiana

Lambert), but other pines that may be defoliated if near an outbreak 

of this sawfly include red (P. resinosa Sol. ex Aiton), eastern white 

(P. strobus L.), and Scotch (P. sylvestris L.) pines.

This sawfly is found in Canada from Nova Scotia west to Alberta and 

in the Great Lakes states of the United States.

Hosts Commonly Attacked

Distribution

Images of Swaine

Jack Pine Sawfly

Figure 1. Adult Swaine 

jack pine sawfly, 

Neodiprion swainei. 

(Thérèse Arcand 

- Natural Resources 

Canada, Canadian 

Forest Service)
642 Forest Pest Insects in North America:

Images of Swaine

Jack Pine Sawfly

(continued)

Figure 2. Eggs of 

Swaine jack pine 

sawfly. (Thérèse Arcand 

- Natural Resources 

Canada, Canadian 

Forest Service)

Figure 3. Larvae of 

Swaine jack pine sawfly. 

(Both photos: Catherine 

Linnen, University of 

Kentucky, Bugwood.org)

Figure 4. Damage to 

jack pine by Swaine jack 

pine sawfly. (Claude 

Monnier - Natural 

Resources Canada, 

Canadian Forest 

Service)
A Photographic Guide 643

Images of Swaine

Jack Pine Sawfly

(continued)

Figure 5. Jack pines 

defoliated by Swaine 

jack pine sawfly. 

(Robert Gagnon 

- Natural Resources 

Canada, Canadian 

Forest Service)

Important Biological Control 

Agents Related to this 

Pest Species

Important natural enemies of this sawfly include a nuclear polyhedrosis 

virus and various larval parasitoids. Red wood ants (Formicidae) were 

also introduced from Manitoba and Italy into Quebec as pupal predators.

http://imfc.cfl.scf.rncan.gc.ca/insecte-insect-eng.asp?geID=6585; 

fact sheet of Natural Resources Canada on biology and control.

Smirnoff, W.A. 1961. Predators of larvae of Neodiprion swainei Midd. 

(Hymenoptera: Tenthredinidae). The Canadian Entomologist 93: 

272-275.

Smirnoff, W.A., J.J. Fettes, and W. Haliburton. 1962. A virus disease of 

Swaine’s jack pine sawfly, Neodiprion swainei Midd., sprayed from an 

aircraft. The Canadian Entomologist 94: 477-486.

McLeod, J.M. 1970. The epidemiology of the Swaine jack-pine sawfly, 

Neodiprion swainei Midd. The Forestry Chronicle April issue: 126-130. 

(Available at http://pubs.cif-ifc.org/doi/pdf/10.5558/tfc46126-2; provides 

details of timing and stand location where outbreaks have occurred in 

Quebec).

Price, P.W. and H.A. Tripp. 1972. Activity patterns of parasitoids 

on the Swaine jack pine sawfly, Neodiprion swainei (Hymenoptera: 

Diprionidae), and parasitoid impact on the host. The Canadian 

Entomologist 104: 1003-1016.

Price, P.W., R.H. MacArthur, and E.O. Wilson. 1973. Parasitoid 

strategies and community organization. Environmental Entomology

2: 623-626.

Finnegan, R.J. and W.A. Smirnoff. 1984. Neodiprion swainei 

(Middleton), Swaine jack pine sawfly (Hymenoptera: Diprionidae). In: 

Kelleher, J.S. and M.A. Hulme (eds.). Biological Control Programmes 

against Insects and Weeds in Canada 1969-1980. Commonwealth 

Agricultural Bureaux, Slough, United Kingdom: 341-348. 

Web Links for Information 

on Swaine Jack Pine Sawfly

Articles
644 Forest Pest Insects in North America:

178. European Pine Sawfly, Neodiprion sertifer (Geoffroy) (Hymenoptera: 

Diprionidae)

Orientation to Pest European pine sawfly, Neodiprion sertifer (Geoffroy), is a European 

species that is invasive in North America. It feeds on many species of 

pines. This sawfly occurs across Canada and widely in the eastern United 

States. The winter is passed as eggs, which hatch in early spring. Larvae 

feed gregariously on old needles. New foliage is never eaten. Larvae 

move from tree to tree as necessary for food. Mature larvae drop from 

foliage to the ground, where they spin a cocoon in the duff and pupate. 

Adults emerge in late summer and lay 6 to 8 eggs per needle in new 

foliage. There is one generation per year. Trees attacked by this sawfly 

are never killed because new foliage is not eaten. Damage consists 

of reduced tree growth in forests or loss of quality in Christmas tree 

plantations. 

European pine sawfly feeds on many species of pines, but especially 

on Scots (Pinus sylvestris L.), red (P. resinosa Sol. ex Aiton), jack 

(P. banksiana Lambert), Japanese red (P. densiflora Siebold & Zucc.), 

and Table mountain pines (P. pungens Lamb.). Other species of pines 

will also be defoliated if they grow near an outbreak of this sawfly.

This sawfly is found in Newfoundland, Nova Scotia, New Brunswick, 

Ontario, Quebec, and British Columbia in Canada, and in the eastern 

United States from New England west to North Dakota, and south to 

Missouri.

Hosts Commonly Attacked

Distribution

Images of European

Pine Sawfly

Figure 1. Adults 

of European pine 

sawfly, Neodiprion 

sertifer; top, female; 

bottom, male (note 

enlarged antennae). 

(Both photos: LouisMichel Nageleisen, 

Département de la 

Santé des Forêts, 

Bugwood.org)
A Photographic Guide 645

Images of European

Pine Sawfly (continued)

Figure 2. Egg scars of European pine sawfly in needles of Scots pine. (Andrea 

Battisti, Universita di Padova, Bugwood.org)

Figure 3. Larvae of 

European pine sawfly. 

(Top: Gyorgy Csoka, 

Hungary Forest 

Research Institute, 

Bugwood.org; bottom: 

Steven Katovich, 

USDA Forest Service, 

Bugwood.org)

Figure 4. Pupal cocoons 

of European pine sawfly. 

(Jim Occi, BugPics, 

Bugwood.org)
646 Forest Pest Insects in North America:

Images of European

Pine Sawfly (continued)

Figure 5. Damage to red pine by European pine sawfly larvae; note that only 

old needles are eaten. (Both photos: Steven Katovich, USDA Forest Service, 

Bugwood.org)

Figure 6. Larvae of European pine sawfly killed by a virus (note the characteristic 

position, hanging head down). (John D. Kegg, New Jersey Department of 

Agriculture, Bugwood.org)
A Photographic Guide 647

Important natural enemies of this sawfly include an imported European 

nuclear polyhedrosis virus that is used effectively as a biopesticide, and 

several European larval parasitoids, which have not provided control of 

this pest. 

http://ohioline.osu.edu/hyg-fact/2000/2555.html; fact sheet of Ohio State 

University on biology and control.

http://ento.psu.edu/extension/factsheets/european-pine-sawfly; fact sheet 

of Pennsylvania State University on biology and control.

http://www.forestpests.org/vermont/europeansawfly.html; fact sheet of 

Vermont Department of Forests, Parks, and Recreation.

http://www.exoticpests.gc.ca/ins_details_eng.asp?pestType=ins&lang=lt

&geID=6583; website of Forest Invasive Alien Species (Government of 

Canada).

Finlayson, L.R. and T. Finlayson. 1958. Parasitism of the European 

Pine Sawfly, Neodiprion sertifer (Geoff.) (Hymenoptera: Diprionidae), 

in Southwestern Ontario. The Canadian Entomologist 90: 223-225. 

(Available at http://pubs.esc-sec.ca/doi/abs/10.4039/Ent90223-4).

Entwistle, P.F., H.F. Evans, K.A. Harrap, and J.S. Robertson. 1978. Field 

trials on the control of the pine sawfly, Neodiprion sertifer, using purified 

nuclear polyhedrosis virus. Technical Report, Unit of Invertebrate 

Virology, Natural Environment Research Council (UK): 62 p.

Gur’yanova, T.M. 1979. Significance of the diapause of the parasite 

Exenterus abruptorius (Ichneumonidae) in the dynamics of numbers of 

the red pine sawfly (Neodiprion sertifer). Zoologicheskii Zhurnal 58 (9): 

1339-1349. 

Important Biological Control 

Agents Related to this 

Pest Species

Web Links for Information 

on European Pine Sawfly

Articles
648 Forest Pest Insects in North America:

179. Virginia Pine Sawfly, Neodiprion pratti pratti (Dyar) (Hymenoptera: 

Diprionidae)

Orientation to Pest Virginia pine sawfly, Neodiprion pratti pratti (Dyar), is a native North 

American sawfly that feeds on Virginia (Pinus virginiana Mill.) and 

shortleaf (P. echinata Mill.) pines. It is found from New Jersey south to 

North Carolina and west to Illinois. The winter is passed as eggs, which 

hatch in early spring. Larvae feed gregariously on old needles. Mature 

larvae drop from foliage to the ground, where they spin cocoons in the 

duff and pupate. Adults emerge in late summer and lay eggs individually 

in needles. There is one generation per year. Trees attacked by this sawfly 

are not killed, but tree growth in forests is reduced. A large outbreak 

of this species (5.6 million acres) occurred in the 1950s in Maryland, 

Virginia, and North Carolina. Note, this species should not be confused 

with Neodiprion pratti (Dyar), a species associated with sand pine 

(P. clausa [Chapm. ex Engelm.] Sarg.).

Virginia pine sawfly feeds on Virginia (P. virginiana Mill.) and shortleaf 

(P. echinata Mill.) pines.

Virginia pine sawfly is found from New Jersey south to North Carolina 

and west to Illinois.

Hosts Commonly Attacked

Distribution

Images of Virginia

Pine Sawfly

Figure 1. Adult male of Virginia pine sawfly, Neodiprion pratti pratti. (USDA Forest 

Service - Region 8 - Southern Archive, USDA Forest Service, Bugwood.org)
A Photographic Guide 649

Images of Virginia

Pine Sawfly (continued)

Figure 2. Egg scars of Virginia pine sawfly on pine needles. (Caleb L. Morris, 

Virginia Department of Forestry, Bugwood.org)

Figure 3. Larvae of Virginia pine 

sawfly. (USDA Forest Service 

- Forest Health Protection, 

Southern Region)

Figure 4. Feeding damage of Virginia pine sawfly. (USDA Forest Service - 

Ashville Archive, USDA Forest Service, Bugwood.org)
650 Forest Pest Insects in North America:

Images of Virginia

Pine Sawfly (continued)

Figure 5. Pine stand defoliated by Virginia pine sawfly. (Caleb L. Morris, Virginia 

Department of Forestry, Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

No information was found on the natural enemies of this species.

http://www.fs.fed.us/r8/foresthealth/idotis/insects/vapinesf.html; USDA 

Forest Service fact sheet on biology and control.

http://pubs.ext.vt.edu/2911/2911-1424/2911-1424.html; Virginia 

Extension Service fact sheet on biology and control.

http://entnemdept.ufl.edu/creatures/trees/sawfly/pine_sawflies.htm; 

fact sheet of the University of Florida; compares some details among 

a number of sawfly species that feed on pine, including Virginia pine 

sawfly.

http://www.forestpests.org/acrobat/not%20linked/gfc-01.pdf; fact sheet 

of the Georgia Forestry Commission; provides drawings that compare 

body markings of larvae of various sawflies that feed on pines.

None

Web Links for Information 

on Virginia Pine Sawfly

Articles
A Photographic Guide 651

180. Hemlock Sawfly, Neodiprion tsugae Middleton (Hymenoptera: 

Diprionidae)

Orientation to Pest The hemlock sawfly, Neodiprion tsugae Middleton, is an important 

native defoliator of western hemlock (Tsuga heterophylla [Raf.] Sarg.) 

in western North America. This sawfly overwinters as eggs, which are 

laid in the fall in needles of the current year’s growth, usually one egg 

per needle. Eggs hatch in spring and the larvae feed into early summer. 

Young larvae usually feed gregariously, but change to feeding singly 

as they mature. The larvae eat the old needles, reducing growth but 

rarely killing trees. Mature larvae drop to the duff where they spin 

cocoons. Usually there is one generation a year, but some larvae take 

more than one year to complete their life cycle. Extensive outbreaks 

on western hemlock have been recorded in natural forests in Oregon, 

British Columbia, and Alaska, often in association with outbreaks of 

blackheaded budworm (Acleris gloverana Walsingham). In coastal 

Alaska, defoliation can be concentrated on large trees on southern and 

western slopes near waterways. In British Columbia when hemlock 

sawfly is associated with blackheaded budworm, thinned stands have 

been reported to suffer heavier defoliation than unthinned stands.

The main host is western hemlock (Tsuga heterophylla [Raf.] Sarg.), but 

in addition, mountain hemlock (T. mertensiana [Bong.] Carr). and Pacific 

silver fir (Abies amabilis Douglas ex J. Forbes) are sometimes attacked 

as well. 

This sawfly is found in coastal forests 

of western North America in Oregon, 

Washington, British Columbia, and 

Alaska. It also occurs in interior 

forests of British Columbia, Idaho, 

and Montana.

Hosts Commonly Attacked

Distribution

Figure 1. North 

American distribution 

of hemlock sawfly, 

Neodiprion tsugae. 

(USDA Forest Service 

• Forest Insect and 

Disease Leaflet 31)
652 Forest Pest Insects in North America:

Images of 

Hemlock Sawfly

Figure 2. Adult of hemlock sawfly. (Edward H. Holsten, USDA Forest Service, 

Bugwood.org)

Figure 3. Larvae of 

hemlock sawfly. (Top: 

USDA Forest Service 

- Region 10 - Alaska 

Archive, USDA Forest 

Service, Bugwood.

org; bottom: Dion 

Manastyrski - Natural 

Resources Canada, 

Canadian Forest 

Service)

Figure 4. Cocoon of 

hemlock sawfly, from 

which the adult has 

emerged. (USDA Forest 

Service Insect and 

Disease Leaflet 31)
A Photographic Guide 653

Images of Hemlock 

Sawfly (continued)

Figure 6. Stand of hemlock showing extensive damage during outbreak of 

hemlock sawfly. (USDA Forest Service - Region 10 - Alaska Archive, USDA 

Forest Service, Bugwood.org)

Figure 5. Feeding 

damage (thin foliage) 

of hemlock sawfly on 

western hemlock. (David 

L. Overhulser, Oregon 

Department of Forestry, 

Bugwood.org)
654 Forest Pest Insects in North America:

Important Biological Control 

Agents Related to this 

Pest Species

Parasitoids attacking hemlock sawfly include the ichneumonids 

Delomerista japonica diprionis Cushman, Oresbius tsugae tsugae

(Cushman), and Itoplectis quadricingulatus (Provancher). A fungus 

(Entomopthora sphaerosperma Fres.) was the most effective control 

observed in studies in Alaska, particularly in wet years.

http://www.fs.fed.us/r10/spf/fhp/leaflets/Fidl31.htm; USDA Forest 

Service Insect and Disease Leaflet 31 on biology and control of 

hemlock sawfly.

http://imfc.cfl.scf.rncan.gc.ca/insecte-insect-eng.asp?geID=1000010; 

fact sheet on this insect by Natural Resources Canada.

Furniss, R. L. and P.B. Dowden. 1941. Western hemlock sawfly, 

Neodiprion tsugae Middleton, and its parasites in Oregon. Journal of 

Economic Entomology 34: 46-52.

Hard, J.S. 1976. Natural control of hemlock sawfly, Neodiprion tsugae

Middleton (Hymenoptera: Diprionidae), populations in southeast Alaska. 

The Canadian Entomologist 108: 485-498.

Hard, J.S. and D.C. Schmiege. 1968. The hemlock sawfly in southeast 

Alaska. USDA Forest Service Research Paper No. PNW-65. Pacific 

Northwest Forestry and Range Exp. Station, Portland, Oregon: 11 p.

Torgersen, T.R. 1968. Parasites of the hemlock sawfly, Neodiprion 

tsugae, in coastal Alaska. Annals of the Entomological Society of 

America 61(5): 1155-1158.

Web Links for Information 

on Hemlock Sawfly

Articles
A Photographic Guide 655

181. Introduced Pine Sawfly, Diprion similis (Hartig) (Hymenoptera: 

Diprionidae)

Orientation to Pest Introduced pine sawfly, Diprion similis (Hartig), is an invasive species in 

North America of Eurasia origin that defoliates eastern white pine (Pinus 

strobus L.) and some other pines. It occurs widely in eastern Canada and 

the United States. Winter is spent in the prepupal stage in a cocoon on 

the tree or in the duff. Insects pupate in early spring and adults emerge 

by May to mid-June. Females lay eggs in rows of up to 10 in slits cut 

in needles of hosts. Young larvae feed in groups, but older larvae feed 

alone. Larvae of the first generation feed on old needles only, but larvae 

of the second generation eat both old and new needles. Normally there 

are two generations per year, but in favorable areas, there may be a 

partial third generation. Infested trees may be defoliated and trees 

may be killed. 

This species feeds on pines, especially eastern white pine (P. strobus). 

Scotch (P. sylvestris L.), red (P. resinosa Sol. ex Aiton), jack 

(P. banksiana Lamb.), and mugo (P. mugo Turra) pines are also attacked.

In the United States, this sawfly is found from Maine west to Minnesota 

and south to North Carolina, Tennessee, and Virginia. In Canada, it is 

present in Newfoundland, Nova Scotia, New Brunswick, Prince Edward 

Island, Quebec, Ontario, and Manitoba.

Hosts Commonly Attacked

Distribution

Images of Introduced

Pine Sawfly

Figure 1. Adult of introduced pine sawfly, Diprion simili. (John H. Ghent, USDA 

Forest Service, Bugwood.org)
656 Forest Pest Insects in North America:

Images of Introduced

Pine Sawfly (continued)

Figure 2. Eggs of introduced pine sawfly inserted into a pine needle. (John H. 

Ghent, USDA Forest Service, Bugwood.org)

Figure 3. Larvae of introduced pine sawfly. (Steven Katovich, USDA Forest 

Service, Bugwood.org)

Figure 4. Cocoon 

(emerged) of introduced 

pine sawfly. (Gyorgy 

Csoka, Hungary Forest 

Research Institute, 

Bugwood.org)
A Photographic Guide 657

Images of Introduced

Pine Sawfly (continued)

Figure 5. Defoliation of eastern white pines due to introduced pine sawfly larvae. 

(John H. Ghent, USDA Forest Service, Bugwood.org)

Figure 6. Emergence of the ichneumonid parasitoid Exenterus amictorius

(Panzer) from a cocoon of introduced pine sawfly. (John H. Ghent, USDA Forest 

Service, Bugwood.org) 
658 Forest Pest Insects in North America:

Important Biological Control 

Agents Related to this 

Pest Species

In Europe, many species of parasitoids have been reared from D. 

similis, including most commonly Aptesis subguttatus (Grav.), A. 

basizonia (Grav.), Exenterus amictorius (Panzer), E. adspersus Hartig., 

Palexorista inconspicua (Meigen), Hypsantyx impressus (Grav.), 

and Monodontomerus dentipes (Dalman). Palexorista inconspicua is 

believed by some to be the most important tachinid parasitoid of D. 

similis in Europe. In North America, D. similis is attacked by several 

European parasitoids that were introduced against other closely related 

invasive sawflies. In Connecticut, nearly 50 percent of D. similis larvae 

were parasitized by a complex of eight parasitoid species, especially 

M. dentipes, which was also one of the most important parasitoids 

in Pennsylvania and New Jersey. In Minnesota, the most common 

parasitoids were E. amictorius, M. dentipes, and Delomerista japonica

Cushman. Diprion similis did not invade the southern United States 

until the 1970s, and, in that region, few parasitoid species were found 

attacking the pest. Monodontomerus dentipes was introduced to the 

region, where it became abundant and was credited with controlling the 

pest in North Carolina. 

http://www.exoticpests.gc.ca/ins_details_eng.asp?pestType=ins&lang=lt

&geID=6552; fact sheet of Environment Canada on biology of species.

http://www.forestpests.org/vermont/introducedsawfly.html; fact sheet 

of the Vermont Department of Forests, Parks and Recreation on biology 

and control. 

http://na.fs.fed.us/spfo/pubs/fidls/intro_sawfly/intro_sawfly.htm; 

USDA Forest Service Forest Insect and Disease Leaflet.

Monroe, H.A.U. 1935. Observations on the habits of an introduced pine 

sawfly Diprion simile Htg. The Canadian Entomologist 67: 137-140. 

Tsao, C.H. and A.C. Hodson. 1956. The effect of different host species 

on the oviposition and survival of the introduced pine sawfly. Journal of 

Economic Entomology 49: 400-401. 

Coppel, H.C., J.W. Mertins, and J.W.E. Harris. 1974. The introduced 

pine sawfly, Diprion similis (Hartig) (Hymenoptera: Diprionidae): 

A review with emphasis on studies in Wisconsin. University of 

Wisconsin-Madison Research Bulletin R 2393: 74 p.

Drooz, A.T.; J.H. Ghent, and C.M. Huber. 1985. Insect parasites 

associated with the introduced pine sawfly, Diprion similis (Hartig) 

(Hymenoptera: Diprionidae), in North Carolina. Environmental 

Entomology 14: 401-403.

Web Links for Information 

on Introduced Pine Sawfly

Articles
A Photographic Guide 659

182. European Spruce Sawfly, Gilpinia hercyniae (Hartig) (Hymenoptera: 

Diprionidae)

Orientation to Pest The European spruce sawfly, Gilpinia hercyniae (Hartig), is an 

introduced sawfly from Europe that feeds on spruce (Picea). Currently, 

this sawfly is found in Canada from the Maritimes west to Manitoba, 

and on the island of Newfoundland. In the United States, it is present 

from the northeast to the Great Lake states. White spruce (Picea glauca

[Moench] Voss) and other species in the genus are attacked. Adults 

emerge in spring and lay eggs in slits cut in needles of host trees. Larvae 

of all ages feed singly; old needles are preferred, but both old and new 

needles are consumed. Mature larvae spin cocoons in which they pupate. 

For the overwintering generation, cocoons are formed in the duff below 

host trees, while non-overwintering cocoons are attached to foliage or 

twigs. Depending on the location, there may be one to three generations 

per year. About a decade or so after the detection of this species in 

North America, outbreaks became widespread and continuous in eastern 

Canada. In the 1940s, biological control of this species was achieved by 

introducing a series of European parasitoids and, accidentally, a nuclear 

polyhedrosis virus. Outbreaks of this species no longer occur in North 

America due to the combined action of these natural enemies.

White spruce (P. glauca [Moench] Voss) is the preferred host, but 

red (P. rubens Sarg.), black (P. mariana [Mill.] Britton, Sterns & 

Poggenburg), and Norway (P. abies [L.] H. Karst.) spruce are attacked.

This sawfly is found from the Maritimes west to Manitoba, and on 

the island of Newfoundland. In the United States, it is present in the 

northeastern States, west to the Great Lakes region.

Hosts Commonly Attacked

Distribution

Images of European

Spruce Sawfly

Figure 1. Adult of the European spruce sawfly, Gilpinia hercyniae. (Gerhard 

Elsner, Biologische Bundesanstalt für Land und Forstwirtschaft, Bugwood.org)
660 Forest Pest Insects in North America:

Images of European

Spruce Sawfly (continued)

Figure 2. Eggs (seen 

as swollen areas, see 

arrow) inside spruce 

needles. 

(Thérèse Arcand 

- Natural Resources 

Canada, Canadian 

Forest Service)

Figure 3. Larvae of the European spruce sawfly. (Gerhard Elsner, Biologische 

Bundesanstalt für Land und Forstwirtschaft, Bugwood.org)

Figure 4. Cocoons of a non-diapausing generation of the European spruce 

sawfly. (Gerhard Elsner, Biologische Bundesanstalt für Land und Forstwirtschaft, 

Bugwood.org)
A Photographic Guide 661

Important Biological Control 

Agents Related to this 

Pest Species

Importations of parasitoids from Europe against the European spruce 

sawfly were begun after detection of a large outbreak in the Gaspé 

region of Quebec, and natural enemy introductions were carried out on 

a massive scale. Millions of sawfly cocoons and eggs were collected in 

Europe and shipped to Canada where their parasitoids were reared and 

released. Eventually a rearing program was established in Canada that 

produced over 800 million parasitoids between 1932 and 1958. Overall 

some 30 species of parasitoids were identified from Europe and Japan 

and introduced into North America. At least seven species established, of 

which the first was Dahlbominus fuscipennis Zett. in Quebec, followed 

by several species of Exenterus. Biological control was eventually 

achieved not by parasitoids but by the accidental introduction of a 

nucleopolyhydrosis virus (Borrelinavirus hercyniae) sometime before 

1938. By 1943, G. hercyniae populations were in marked decline with 

B. hercyniae identified as the most important cause. This virus, together 

with the introduced parasitoids, caused a widespread reduction of 

G. hercyniae of 90-95 percent by 1945. Once outbreaks had ceased 

G. hercyinae populations were regulated by the combination of 

B. hercyniae and two introduced parasitoids Drino bohemica (Mesn.) 

and Exenterus vellicatus Cush. Minor outbreaks continued to occur for 

some years, on the edge of the species’ range and in forests that had 

been sprayed with DDT to control populations of the spruce budworm 

(Choristoneura fumiferana Clem.); areas where the pest had temporarily 

outpaced the expansion of the ranges of the introduced natural enemies 

or where natural enemies had been killed by pesticide use. 

http://imfc.cfl.scf.rncan.gc.ca/insecte-insect-eng.asp?geID=6555; 

fact sheet of Natural Resources Canada.

Clark, R.C., L.J. Clarke, and K.E. Pardy. 1973. Biological control of the 

European spruce sawfly in Newfoundland. Bi-monthly Research Notes

29(1): 2-3.

Adams, P.H.W. and P.F. Entwistle. 1981. An annotated bibliography of 

Gilpinia hercyniae (Hartig), European spruce sawfly. Occasional Papers

No. 11. Commonwealth Forestry Institute: 58 p. 

McCugan, B.M. and H.C. Coppell. 1962. A review of biological control 

attempts against insects and weeds in Canada. Part II. Biological 

control of forest insects, 1910-1958. Technical Communication No. 2, 

Commonwealth Institute of Biological Control, Trinidad. Commonwealth 

Agriculture Bureaux, Farnahm Royal, Bucks, England: 35-177.

Web Links for Information 

on European Spruce Sawfly

Articles
662 Forest Pest Insects in North America:

183. Larch Sawfly, Pristiphora erichsonii (Hartig) (Hymenoptera: 

Tenthridinidae)

Orientation to Pest Larch sawfly, Pristiphora erichsonii (Hartig), was historically a serious 

pest of larch (Larix) in North America. It is present throughout Canada, 

Alaska, and most of the northern tier of US states. Distinct strains of 

the species have been recognized, with different geographical origins. 

A debate has existed over whether strains of this species found in North 

American before 1920 were native to North America or were invasive 

from Europe at an earlier date. Further complicating matters is the 

accidental introduction of additional strains, definitely from Europe, 

that occurred during a biological control program (1910-1930) against 

the species that released cocoons (both parasitized and unparasitized) 

collected in Europe in the field in Canada. This sawfly overwinters as 

prepupae in cocoons in the duff. Adults emerge in spring and lay eggs in 

new shoots, causing curling. All larch sawfly adults are females. Newly 

hatched larvae feed in groups, mainly on the needle clusters of older 

twigs. Dense populations can defoliate whole trees. Mature larvae drop 

to the ground to spin cocoons. There is one generation per year in most 

locations, but some individuals may remain in their cocoons for two 

or three winters before emerging. Damaging outbreaks have occurred 

periodically. During outbreaks, trees are not commonly killed, but wood 

growth is reduced. Weakened surviving trees may also be at increased 

risk of bark beetle attack. 

Larch sawfly feeds on eastern larch (Larix laricina [Du Roi] K. Koch), 

western larch (L. occidentalis Nutthal), and alpine larch (L. lyallii Parl.).

Larch sawfly occurs in all Canadian provinces, Alaska, all the northern 

tier of U.S. states, as well as Maryland, North Carolina, and West 

Virginia.

Hosts Commonly Attacked

Distribution

Images of 

Larch Sawfly

Figure 1. Adult of larch 

sawfly, Pristiphora 

erichsonii. (Natural 

Resources Canada, 

Canadian Forest 

Service)
A Photographic Guide 663

Images of 

Larch Sawfly (continued)

Figure 2. Larvae of larch sawfly. (Steven Katovich, USDA Forest Service, 

Bugwood.org)

Figure 3. Cocoons of larch sawfly, showing adult emergence holes. (Arnold T. 

Drooz, USDA Forest Service, Bugwood.org)

Figure 4. Larch needles showing feeding by larch sawfly larvae. (Dayle D. 

Bennett, Bugwood.org)
664 Forest Pest Insects in North America:

Images of 

Larch Sawfly (continued)

Figure 5. A larch stand in Minnesota showing partial (50 percent) defoliation 

caused by larch sawfly. (Arnold T. Drooz, USDA Forest Service, Bugwood.org)

Figure 6. Landscape level defoliation of larch in Minnesota in 1953 caused by 

larch sawfly. (Arnold T. Drooz, USDA Forest Service, Bugwood.org)

The history of biological control efforts against larch sawfly in North 

America is complex. See Van Driesche et al. (1996) for a detailed history. 

Natural enemies in North America that are important to the population 

dynamics of larch sawfly include a tachinid (Bessa harveyi [Townsend]), 

a guild of native small mammals, and two introduced ichneumonid 

parasitoids, Mesoleius tenthredinis Morely and Olesicampe benefactor

Hinz. An important factor mediating outcomes in early stages of the 

biological control program was variation in the ability of the several 

sawfly strains to encapsulate the eggs of the parasitoid M. tenthredinis. 

This was subsequently resolved by introduction of a second strain that 

was able to resist encapsulation.

Important Biological Control 

Agents Related to this 

Pest Species
A Photographic Guide 665

http://www.forestry.ubc.ca/fetch21/FRST308/lab5/pristiphora_erichsonii/

sawfly.html; fact sheet of the University of British Columbia on biology.

Turnock, W.J. 1960. Ecological life-history of the larch sawfly, 

Pristiphora erichsonii (Htg.) (Hymenoptera: Tenthredinidae), in 

Manitoba and Saskatchewan. The Canadian Entomologist 92: 500-516.

Hu, F. 1964. Population dynamics of the larch sawfly. The Canadian 

Entomologist 96: 160-161.

Turnock, W.J. 1972. Geographical and historical variability in 

population patterns and life systems of the larch sawfly (Hymenoptera: 

Tenthredinidae). The Canadian Entomologist 104: 1883-1900.

Wong, H.R. 1974. The identification and origin of the strains of the larch 

sawfly, Pristiphora erichsonii (Hymenoptera: Tenthredinidae), in North 

America. The Canadian Entomologist 106: 1121-1131.

Maltais, P.P., J.J. Juillet, and D.D. de Oliveira. 1980. Ecology and 

population dynamics of the larch sawfly, Pristiphora erichsonii (Htg.) 

in Kouchibouguac National Park, New Brunswick. Annals of the 

Entomological Society of Quebec 25: 141-162.

Krause, S.L. and K.F. Raffa. 1996. Defoliation tolerance affects the 

spatial and temporal distributions of larch sawfly and natural enemy 

populations. Ecological Entomology 21: 101-111.

Van Driesche, R.G., S. Healy, and R.C. Reardon. 1996. Biological 

Control of Arthropod Pests of the Northeastern and North Central 

Forests in the United States: A review and recommendations. FHTET 

96-19, December 1996, USDA Forest Service, Morgantown, WV. 

(See http://www.forestpestbiocontrol.info/fact_sheets/documents/

arthropodpestsnortheastern_northcentral.pdf).

Articles

Web Links for Information 

on Larch Sawfly
666 Forest Pest Insects in North America:

184. Mountain Ash Sawfly, Pristiphora geniculata (Hartig) (Hymenoptera: 

Tenthridinidae)

Orientation to Pest Mountain ash sawfly, Pristiphora geniculata (Hartig), is a European 

tenthredinid sawfly that is invasive in North America. In North America, 

it feeds on species of Sorbus. Mountain ash sawfly occurs in Canada 

east of central Ontario and in the northeastern United States. The winter 

is passed as a prepupa in a cocoon in the soil or leaf litter. Pupation 

occurs in the spring and adults emerge soon after. Eggs are deposited 

in slits cut in the edges of the leaves of the host trees. Newly hatched 

larvae feed on the leaf edges. When disturbed, larvae raise their bodies 

in an “s” position. Young larvae feed gregariously, but older larvae feed 

individually. Larvae eat entire leaves except for the midribs. Mature 

larvae of the overwintering generation drop to the soil and spin their 

cocoons. Mountain ash sawfly is primarily a pest of ornamentals and 

in the wild has largely been suppressed by the introduced parasitoid 

Olesicampe geniculatae Quednau and Lim. In all but the northern part 

of its range in North America, there are two generations per year.

This species feeds on American mountain ash (Sorbus americana

Marshall) and European mountain ash (S. aucuparia L.).

Mountain ash sawfly occurs in Canada east of central Ontario and in 

the northeastern United States, including New York, New Jersey, and 

Michigan.

Hosts Commonly Attacked

Distribution

Images of 

Mountain Ash Sawfly

Figure 1. Adult of 

mountain ash sawfly, 

Pristiphora geniculata. 

(James Lindsey, 

Bugwood.org)

Figure 2. Eggs of 

mountain ash sawfly, 

inserted into edges of 

leaves of the host plant. 

(L.J. Lipovsky, Maine 

Forest Service)
A Photographic Guide 667

Images of Mountain Ash 

Sawfly (continued)

Figure 3. Larvae of 

mountain ash sawfly; 

young larvae feeding in 

a group (top) and older 

larvae feeding alone 

(bottom). (Top: Steven 

Katovich, USDA Forest 

Service, Bugwood.org; 

bottom: E. Bradford 

Walker, Vermont 

Department of Forests, 

Parks and Recreation, 

Bugwood.org)

Figure 4. Foliage of mountain ash stripped of all but mid ribs by mountain ash 

sawfly larvae. (Joseph O’Brien, USDA Forest Service, Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

This introduced sawfly has been controlled by releases of the parasitoid 

Olesicampe geniculatae.
668 Forest Pest Insects in North America:

Web Links for Information 

on Mountain Ash Sawfly

http://www.forestpests.org/vermont/mountainashsawfly.html; fact sheet 

of the Bugwood network.

http://maine.gov/doc/mfs/mtnash.htm; fact sheet of the Maine 

Department of Conservation on biology and control of insect.

http://www.fs.fed.us/r6/nr/fid/invasives/mtn-ash-sawfly.shtml; fact sheet 

of USDA Forest Service Forest Health Protection Pacific Northwest 

Region—biology and control.

Forbes, R.S. and L. Daviault.1964. The biology of the mountain ash 

sawfly, Pristiphora geniculata (Htg.) (Hymenoptera: Tenthredinidae), in 

eastern Canada. The Canadian Entomologist 98: 1117-1133. 

Quednau, F.W. 1990. Introduction, permanent establishment, and 

dispersal in eastern Canada of Olesicampe geniculatae Quednau and Lim 

(Hymenoptera: Ichneumonidae), an important biological control agent of 

the mountain ash sawfly, Pristiphora geniculata (Hartig) (Hymenopttera: 

Tenthredinidae). The Canadian Entomologist 122: 921-934. 

West, R.J., P.L. Dixon, F.W. Quednau, K.P. Lim, and K. Hiscock. 

1994. Establishment of Olesicampe geniculatae Quednau and Lim 

(Hymenoptera: Ichneumonidae) to control the mountain ash sawfly, 

Pristiphora geniculata (Hartig) (Hymenopttera: Tenthredinidae) in 

Newfoundland. The Canadian Entomologist 126: 7-11. 

West, R.J., P.L. Dixon, F.W. Quednau, and K.P. Lim. 2001. 

Pristiphora geniculata (Hartig), mountain ash sawfly (Hymenoptera: 

Tenthredinidae). In: Mason, P.G. and J.T. Huber (eds.). Biological 

Control Programmes in Canada, 1981-2000. CABI Publishing, 

Wallingford, UK: 228-230. 

Articles
A Photographic Guide 669

185. Yellowheaded Spruce Sawfly, Pikonema alaskensis (Rohwer) 

(Hymenoptera: Tenthredinidae)

Orientation to Pest The yellowheaded spruce sawfly, Pikonema alaskensis (Rohwer), is a 

native sawfly found throughout northeastern and northwestern North 

America that feeds on all species of native and introduced spruce (Picea). 

It overwinters as prepupae in the duff and adults emerge in spring. Eggs 

are laid in the current season’s needles just as buds begin to flush in 

the spring. Larvae feed on the new needles primarily, but may exploit 

old needles if new needles become scarce. In summer, fully developed 

larvae drop to the ground and spin cocoons (in which they molt to the 

prepupal stage) in the duff or topsoil. Damage occurs mainly in the upper 

crown of young, open-grown spruce, especially on trees in ornamental 

and shelterbelt plantings; mature trees are rarely attacked. Several years 

of heavy feeding may kill the leader and upper crown branches of trees. 

There is one generation per year.

Hosts of yellowheaded spruce sawfly include all native spruces in North 

America: Engelmann (Picea engelmannii Parry ex Engelm.), white 

(P. glauca [Moench] Voss), black (P. mariana [Mill.] Britton, Sterns & 

Poggenburg), Sitka (P. sitchensis [Bong.] Carr.), and Colorado blue 

(P. pungens Engelm.), and the introduced Norway spruce (P. abies [L.] 

Karst.). 

This sawfly occurs in throughout the range of spruce in North America, 

and can be found from Alaska to Maine.

Hosts Commonly Attacked

Distribution

Images of Yellowheaded

Spruce Sawfly

Figure 1. Adult of 

yellowheaded spruce 

sawfly, Pikonema 

alaskensis. 

(D.K.B. Cheung)
670 Forest Pest Insects in North America:

Images of Yellowheaded

Spruce Sawfly (continued)

Figure 2. Ovipostion 

cuts in needles made 

by yellowheaded spruce 

sawfly. (Thérèse Arcand 

- Natural Resources 

Canada, Canadian 

Forest Service)

Figure 3. Larvae of 

yellowheaded spruce 

sawfly; top, young 

larvae and bottom, 

mature larvae. (Top: 

Thérèse Arcand 

- Natural Resources 

Canada, Canadian 

Forest Service; bottom: 

E. Bradford Walker, 

Vermont Department of 

Forests, Parks 

and Recreation, 

Bugwood.org)

Figure 4. Prepupa of 

yellowheaded spruce 

sawfly in cocoon 

(opened). 

(D.K.B. Cheung)
A Photographic Guide 671

Images of Yellowheaded

Spruce Sawfly (continued)

Figure 5. Damage 

(top) to white spruce 

from yellowheaded 

spruce sawfly; close 

up (bottom) of larvae 

feeding on spruce. 

(Top: Steven Katovich, 

USDA Forest Service, 

Bugwood.org; bottom: 

E. Bradford Walker, 

Vermont Department 

of Forests, Parks 

and Recreation, 

Bugwood.org)

Figure 6. Stand of 

spruce showing injury 

from yellowheaded 

spruce sawfly. (USDA 

Forest Service - 

Northeastern Area 

Archive, USDA Forest 

Service, Bugwood.org)
672 Forest Pest Insects in North America:

Important Biological Control 

Agents Related to this 

Pest Species

The natural enemies of this species have been studied in Minnesota, 

Maine and Nova Scotia. A monitoring trap has been developed for one 

parasitoid, the ichneumonid Syndipnus rubiginosus Walley.

http://www.na.fs.fed.us/spfo/pubs/gtr/sprucesawfly/biology.htm; a very 

detailed fact sheet of the USDA Forest Service on biology of this species.

http://www.fs.fed.us/r10/spf/fhp/leaflets/yellowhd_spruce_sawfly.pdf; 

fact sheet of the USDA Forest Service on biology and control. 

http://gardenline.usask.ca/pests/yellow.html; fact sheet of the University 

of Saskatchewan on biology and control.

http://imfc.cfl.scf.rncan.gc.ca/insecte-insect-eng.asp?geID=7875; 

fact sheet of the Natural Resources Canada on biology and phenology.

http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/opp3005; fact 

sheet of the Alberta Department of Agriculture, on biology and control.

http://www.entomology.umn.edu/cues/Web/225YellowheadedSpruce

Sawfly.pdf; fact sheet of the University of Minnesota on biology and 

control.

http://www.maine.gov/doc/mfs/yhss.htm; fact sheet of the Maine 

Department of Conservation on biology and control.

http://www.forestpests.org/vermont/yellowheadsawfly.html; fact sheet 

of the Vermont Department of Forests, Parks, and Recreation.

http://www.fs.fed.us/r6/nr/fid/fidls/fidl-69.pdf; USDA Forest Service 

Forest Pest Leaflet No. 69.

Thompson, L.C. and H.M. Kulman. 1980. Parasites of the yellowhead 

spruce sawfly, Pikonema alaskensis (Hymenoptera: Tenthredinidae), in 

Maine and Nova Scotia. The Canadian Entomologist 112: 25-29.

Katovich, S.A., D.G. McCullough, and R.A. Haack. 1995. Yellowheaded 

spruce sawfly: its ecology and management. General Technical Report 

No. NC-179. USDA Forest Service. Michigan. 

Thurston, G.S. 2001. Pikonema alaskensis (Rohwer), yellowheaded 

spruce sawfly (Hymenoptera: Tenthredinidae). In: Mason, P.G. and J.T. 

Huber (eds.). Biological Control Programmes in Canada, 1981-2000. 

CABI Publishing, Wallingford, UK: 219-221.

Johns, R.C., D.P. Ostaff, and D.T. Quiring. 2006. Sampling procedures 

for evaluating yellowheaded spruce sawfly density and defoliation in 

juvenile black spruce stands. Journal of the Acadian Entomological 

Society 2: 1-12.

Johns, R.C., D.P. Ostaff, and D.T. Quiring. 2006. Relationships between 

yellowheaded spruce sawfly density and defoliation on juvenile black 

spruce. Forest Ecology and Management 228: 51-60.

Web Links for Information on 

Yellowheaded Spruce Sawfly

Articles
A Photographic Guide 673

186. Birch Leafminer, Fenusa pumila (Leach) (Hymenoptera: Tenthridinidae)

Orientation to Pest The birch leafminer, Fenusa pumila (Leach) (formerly known as Fenusa 

pusilla [Lepeletier]), is a European sawfly that was mines the leaves 

of several species of birch (Betula) in North America, where it invaded 

just prior to the 1920s. It is found principally in southeastern Canada 

and the northeastern United States, in the range of its main hosts, gray 

(Betula populifolia Marshal) and paper birch (B. papyrifera Marshal). 

This sawfly overwinters as prepupae in earthen cells in the soil. Pupation 

occurs in spring and adults emerge near bud break. Eggs are laid singly 

in unfolding leaves, and larvae create leafmines where they feed. Mines 

are blotch shaped and enlarge and eventually merge as larvae grow. In 

New England, there is only one full generation per year, but a small 

fraction of the first and second generations develop to adults without 

diapause and emerge to produce a partial second and third generations. 

Before the 1980s, birch leafminer densities were high enough so that 

most leaves of white and gray birches in landscapes or road edges 

were mined; mined leaves being completely browned. This created an 

aesthetic problem on landscape trees and likely reduced the vigor of 

forest trees. In the period of 1970-2000, birch leafminer was subjected to 

biological control through introduction of its specialized parasitoids from 

Europe and densities in the northeastern United States have now declined 

to low pest levels (<5 percent leaves mined). 

The principal birch species used as hosts are gray (B. populifolia) and 

paper (B. papyrifera) birch. Yellow (B. alleghaniensis Britton) and 

black (=sweet) (B. lenta L.) birch are not attacked. Several introduced 

European birches are also attacked in landscape plantings.

This sawfly occurs from Newfoundland (Canada) south to Maryland and 

west to Minnesota and Iowa, with isolated populations also in Oregon, 

Washington, and Alaska, especially on introduced birches planted as 

ornamentals.

Hosts Commonly Attacked

Distribution

Images of 

Birch Leafminer

Figure 1. Adults of birch leafminer, Fenusa pumila; left, adult on young birch leaf; 

right, close up. (Left: Steven Katovich, USDA Forest Service, Bugwood.org; 

right: Cheryl Moorehead, individual, Bugwood.org)
674 Forest Pest Insects in North America:

Images of Birch 

Leafminer (continued)

Figure 2. Eggs of birch 

leafminer (points), 

surrounded by yellow 

halos of tissue. (Thérèse 

Arcand - Natural 

Resources Canada, 

Canadian Forest 

Service)

Figure 3. Small mines of birch leafminer, showing young larvae feeding in 

separate mines (top); bottom, close up on a single mine, with larva visible. (Top: 

Steven Katovich, USDA Forest Service, Bugwood.org; bottom: Joseph O’Brien, 

USDA Forest Service, Bugwood.org)
A Photographic Guide 675

Images of Birch 

Leafminer (continued)

Figure 4. Middle-age (top) and older (bottom) larvae of birch leafminer, showing 

fusion of mines as larvae increase in size. (Top: Brian Kunkel, University of 

Delaware, Bugwood.org; bottom: E. Bradford Walker, Vermont Department of 

Forests, Parks and Recreation, Bugwood.org)

Figure 5. Close up of damage on branch heavily mined by birch leafminer. 

(Whitney Cranshaw, Colorado State University, Bugwood.org)
676 Forest Pest Insects in North America:

Images of Birch 

Leafminer (continued)

Figure 6. High density 

of mining by birch 

leafminer. (Steven 

Katovich, USDA Forest 

Service, Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

Two European ichneumonids (Lathrolestes nigricollis [Thompson] and 

Grypocentrus albipes Ruthe) and one eulophid (Chrysocharis nitetis

[Wilkinson]) were introduced into North America for biological control 

of the birch leafminer. Lathrolestes nigricollis is the only species to 

have become widely established. At the level of individual release sites, 

L. nigricollis has lowered pest density from 50 to <5 percent of first 

generation leaves being mined. At the landscape level, this parasitoid 

has suppressed this leafminer to insignificant levels throughout the 

northeastern United States, with the exception of southern New Jersey. 

http://njaes.rutgers.edu/pubs/publication.asp?pid=FS1164; fact sheet of 

Rutgers University (New Jersey) on biology and control.

http://www.extension.umn.edu/distribution/horticulture/DG6134.html; 

fact sheet of University of Minnesota Extension on biology and control. 

http://www.invasiveforestinsectandweedbiocontrol.info/target_pests/

insects_mites/Birchleafminer.htm; fact sheet of the University of 

Massachusetts on biological control of birch leafminer.

Web Links for Information 

on Birch Leafminer
A Photographic Guide 677

Articles Cheng, H.H. and E.J. LeRoux. 1965. Preliminary life tables and notes 

on mortality factors of the birch leaf miner, Fenusa pusilla (Lepeletier) 

(Hymenoptera: Tenthredinidae), on blue birch, Betula caerulea grandis

Blanchard, in Quebec. Annals of the Entomological Society of Quebec

11: 81-104.

Eichhorn, O. And H. Pschorn-Walcher. 1973. The parasites of the birch 

leaf-mining sawfly (Fenusa pusilla (Lep.), Hym.: Tenthredinidae) in 

Central Europe. Technical Bulletin of the Commonwealth Institute of 

Biological Control No. 16: 79-104.

Fuester, R.W., P.B. Taylor, W.H. Day, R.M. Hendrickson, Jr., and E.M. 

Blumenthal. 1984. Introduction of exotic parasites for biological control 

of the birch leafminer (Hymenoptera: Tenthredinidae) in the Middle 

Atlantic states. Journal of Economic Entomology 77: 1565-1570.

Van Driesche, R.G., R. Childs, R.A. Casagrande, and L. Tewksbury. 

1997. Establishment, distribution, and impact in southern New England 

of Lathrolestes nigricollis (Thompson) (Hymenoptera: Ichneumonidae), 

an introduced parasitoid of the birch leafminer, Fenusa pusilla

(Lepeletier) (Hymenoptera: Tenthredinidae). The Canadian Entomologist

129: 601-611.

Langor, D.W., S.C. Digweed, and J.R. Spence. 2001. Fenusa pusilla

(Lepeletier), birch leafminer, and Profenusa thomsoni (Konow), 

ambermarked birch leafminer (Hymenoptera: Tenthredinidae). In: 

Mason, P.G. and J.T. Huber (eds.). Biological Control Programmes in 

Canada, 1981-2000. CABI Publishing, Wallingford, UK: 123-127.

Casagrande, R., R.G. Van Driesche, M. Mayer, R. Fuester, D. Gilrein, 

L. Tewksbury, and H. Faubert. 2009. Biological control of Fenusa pusilla

(Hymenoptera: Tenthredinidae) in the northeastern United States: a 

thirty-four year perspective on efficacy. Florida Entomologist 92: 

243-247. (Available at http://www.fcla.edu/FlaEnt/fe92p243.pdf).
678 Forest Pest Insects in North America:

187. Ambermarked Birch Leafminer, Profenusa thomsoni (Konow) 

(Hymenoptera: Tenthridinidae)

Orientation to Pest The ambermarked birch leafminer, Profenusa thomsoni (Konow), is 

a European sawfly that feeds inside the leaves of several species of 

birch (Betula). It invaded North America at the beginning of the 20th 

century but was first reported in Canada in 1959. It is found both in 

the northeastern United States (New England through the Great Lakes 

region) and in eastern Canada from the Maritimes to Manitoba, where 

it is not considered a pest because of its low densities. It also occurs in 

western Canada and Alaska, where it reached high densities in Alberta 

(1990s) and Alaska (2000-2008), especially in urban areas, before 

being brought under biological control with an introduced parasitoid 

and two native species. This sawfly overwinters as prepupae in earthen 

cells in the soil. Pupation occurs in the spring, and adults emerge in 

early summer. Eggs are inserted singly into tissue of mature leaves, and 

larvae create leafmines where they feed. The blotch-shaped mines of this 

species increase in size and several mines may merge as larvae grow. 

In Alaska there is one generation per year; however, there are two in 

Massachusetts. 

The principal birch species used as hosts by ambermarked birch 

leafminer are gray (Betula populifolia Marshal) and paper (B. papyrifera

Marshal) birch, but yellow birch (B. alleghaniensis Britt.) is also reported 

as a host. Several introduced European birches are also attacked in 

landscape plantings.

This sawfly occurs from the northeastern United States (New England to 

the Great Lake States), eastern Canada from the Maritimes to Manitoba, 

in western Canada (Alberta, Northwest Territories), and Alaska. Small 

urban populations are found in additional locations (e.g., Bozeman, 

Montana) and many of these may be unrecognized, being taken for 

mines of Fenusa pumila Leach. 

Hosts Commonly Attacked

Distribution

Images of Ambermarked

Birch Leafminer

Figure 1. Adult of 

ambermarked birch 

leafminer, Profenusa 

thomsoni. (Thérèse 

Arcand - Natural 

Resources Canada, 

Canadian Forest 

Service)
A Photographic Guide 679

Images of Ambermarked

Birch Leafminer (continued)

Figure 2. Eggs of 

ambermarked birch 

leafminer. (Thérèse 

Arcand - Natural 

Resources Canada, 

Canadian Forest 

Service)

Figure 3. Mine of 

nearly mature larva of 

ambermarked birch 

leafminer. (Thérèse 

Arcand - Natural 

Resources Canada, 

Canadian Forest 

Service)

Figure 4. Older instar 

of ambermarked birch 

leafminer, with mine 

opened to reveal 

larva. (Thérèse Arcand 

- Natural Resources 

Canada, Canadian 

Forest Service)

Figure 5. Close up of 

branch with mines of 

ambermarked birch 

leafminer. (René Pâquet 

- Natural Resources 

Canada, Canadian 

Forest Service)
680 Forest Pest Insects in North America:

Images of Ambermarked

Birch Leafminer (continued)

Figure 6. Birch trees 

(brown) in Alaska heavily 

mined by ambermarked 

birch leafminer. (Chris 

MacQuarrie, University 

of Alberta)

Figure 7. Important 

parasitoids of 

ambermarked birch 

leafminer in Alaska: 

Aptesis segnis

(top), Lathrolestes 

soperi (middle), and 

Lathrolestes thomsoni 

(bottom). (All three 

photos: Anna Soper, 

Bugwood.org)
A Photographic Guide 681

Important Biological Control 

Agents Related to this 

Pest Species

Three ichneumonids (Lathrolestes soperi Reshchikov, L. thompsoni

Reshchikov, and Aptesis segnis [Provancher]) are important biological 

control agents of this leafminer. The two Lathrolestes species attack the 

host larva in the mine. Lathrolestes soperi is known from Anchorage, 

Alaska and is of unknown origin. This species is particularly common 

in forested habitats. Lathrolestes thompsoni is a species that was 

observed to provide control of this leafminer in Edmonton, Alberta, and 

was moved to Anchorage, Alaska, where it was established to provide 

biological control. Aptesis segnis is a facultative hyperparasitoid that 

attacks the host (or parasitoid) in the host’s pupal cells in the soil. 

http://imfc.cfl.scf.rncan.gc.ca/insecte-insect-eng.asp?geID=7926; 

fact sheet of the Natural Resouces Canada, on biology and phenology.

Digweed, S.C., R.L. McQueen, J.R. Spence, and D.W. Langor. 2003. 

Biological control of the ambermarked birch leafminer, Profenusa 

thomsoni (Hymenoptera: Tenthredinidae), in Alberta. Information Report 

NOR-X-389. Natural Resources Canada, Canadian Forest Service, 

Northern Forestry Centre, Edmonton, Alberta: 8 p.

Digweed, S.C. and D.W. Langor. 2004. Distributions of leafmining 

sawflies (Hymenoptera: Tenthredinidae) on birch and alder in 

northwestern Canada. The Canadian Entomologist 136: 727-731.

Digweed, S.C., C.J.K. MacQuarrie, D.W. Langor, D.J.M. Williams, 

J.R. Spence, K. Nystrom, and L. Morneau. 2009. Current status of 

invasive alien birch-leafmining sawflies (Hymenoptera: Tenthredinidae) 

in Canada, with keys to species. The Canadian Entomologist 141: 

201-235.

Reshchikov, A.V., A. Soper and R.G. Van Driesche. 2010. Revision of the 

Nearctic species of Lathrolestes (Hymenoptera: Ichneumonidae), with 

special reference to species attacking Betula leaf mining Tenthredinidae 

(Hymenoptera). Zootaxa 2614: 1-17.

Web Links for Information 

on Ambermarked 

Birch Leafminer

Articles
682 Forest Pest Insects in North America:

188. Sirex Woodwasp, Sirex noctilio (Fabricius) (Hymenoptera: Siricidae)

Orientation to Pest Sirex woodwasp, Sirex noctilio (Fabricius), is a European woodwasp 

that is widely invasive in the Southern Hemisphere. More recently it 

has also become established in the United States and Canada, with the 

initial discovery in New York in 2004. This species is a major threat to 

pines. In contrast to native North American woodwasps that attack only 

dead and dying trees, Sirex woodwasp can attack and kill living pines. 

At low population densities, the wasp selects suppressed, stressed, or 

injured trees for egg laying. Foliage of infested trees initially wilts and 

turns red in 3-6 months following attack. Infested trees often have pearly 

resin beads exuding from the drill holes where eggs were laid. Larval 

galleries are tightly packed with fine white sawdust and adults chew 

round exit holes that vary from 3 to 9 mm in diameter. Sirex noctilio is 

expected to complete one generation per year throughout most of the 

United States. Adult emergence occurs from July through September, 

with peak emergence during August. When eggs are laid, the female 

wasp also injects into the tree both a toxic mucus and a symbiotic fungus 

(Amylostereum areolatum [Fr.] Boidin). The toxic mucus shuts down the 

water transport, allowing the fungus to grow rapidly and kill the tree. 

The fungus also provides nutrition for the developing woodwasp larvae. 

Females can produce 25 to 450 eggs in their lifetime, depending upon 

their size. The larval stage generally takes 10-11 months.

In addition to its preferred pine hosts (Pinus), S. noctilio can occasionally 

use spruce (Picea), fir (Abies), larch (Larix), and Douglas fir 

(Pseudotsuga menziesii [Mirb.] Franco).

Sirex noctilio is native to Eurasia and North Africa, but it has invaded the 

Southern Hemisphere (New Zealand, Australia, Argentina, Chile, Brazil, 

Uruguay, and South Africa). Most recently, it has also been introduced 

to the United States (Michigan, New York, Ohio, Pennsylvania, and 

Vermont) and Canada. 

Hosts Commonly Attacked

Distribution

Figure 1. Worldwide 

distribution of Sirex 

noctilio, before its 

invasion in North 

America. 

(Dennis Haugen, 

Bugwood.org)
A Photographic Guide 683

Images of 

Sirex Woodwasp

Figure 2. Mating pair 

of Sirex woodwasps 

(top: female left, male 

right) and mounted 

adult male (bottom). 

(Top: Vicky Klasmer, 

Instituto Nacional 

de Tecnologia 

Agropecuaria, 

Bugwood.org; 

bottom: Pest and 

Diseases Image Library, 

Bugwood.org)

Figure 3. Larvae of 

Sirex noctilio in galleries 

inside wood. (Top: 

Vicky Klasmer, Instituto 

Nacional de Tecnologia 

Agropecuaria, 

Bugwood.org; bottom: 

Dennis Haugen, 

Bugwood.org)
684 Forest Pest Insects in North America:

Images of Sirex 

Woodwasp (continued)

Figure 4. Wood sawn from a tree damaged by Sirex noctilio. (Dennis Haugen, 

Bugwood.org)

Figure 5. Cambial 

staining caused by 

the symbiotic fungus 

(Amylostereum 

areolatum) that is 

transmitted by Sirex 

noctilio. White plugs are 

larval galleries packed 

with excrement (frass). 

(Vicky Klasmer, 

Instituto Nacional 

de Tecnologia 

Agropecuaria, 

Bugwood.org)
A Photographic Guide 685

Images of Sirex 

Woodwasp (continued)

Figure 6. Emergence 

holes of Sirex noctilio. 

The round exit holes 

vary from 3 to 9 mm 

in diameter. (Dennis 

Haugen, Bugwood.org)

Figure 7. Resin beads 

from Sirex noctilio

oviposition drills in red 

pine. (David Williams, 

USDA APHIS, 

Bugwood.org)
686 Forest Pest Insects in North America:

Images of Sirex 

Woodwasp (continued)

Figure 8. Tree mortality 

(80-90 percent) from a 

Sirex noctilio outbreak in 

a 15-year-old plantation 

in South Australia in 

1989. (Dennis Haugen, 

Bugwood.org)

Figure 9. Life cycles 

of the two forms of the 

nematode Beddingia 

siricidicola. (Dennis 

Haugen, Bugwood.org)
A Photographic Guide 687

Images of Sirex 

Woodwasp (continued)

Figure 10. Applying nematodes to a Sirex noctilio-infested tree for biological 

control. Inoculation holes are made with a special punch hammer. (Dennis 

Haugen, Bugwood.org)

Figure 11. Sirex noctilio parasitoids, Rhyssa persuasoria (left) and Rhyssa 

lineolata (right). (Kevin Dodds, USDA Forest Service, Bugwood.org)
688 Forest Pest Insects in North America:

Important Biological Control 

Agents Related to this 

Pest Species

Several parasitoids have been introduced from Europe and North 

America into New Zealand and Australia for biological control of Sirex 

woodwasps in pine plantations. The most effective species were Rhyssa 

persuasoria (L.), Megarhyssa nortoni (Cresson), and Ibalia leucospoides

Hochenwald. However, the highest level of control was ultimately 

provided in Australia by a parasitic nematode (Beddingia siricidicola

[Bedding]). This nematode invades the eggs of female woodwasps and is 

transported by them to new egg laying sites. The growing nematode can 

develop into either of two very different forms: one is a fungus-eating 

form that lives on the symbiotic fungus transmitted by the woodwasp 

and the other is a parasite that develops inside woodwasp larvae and 

adults. Infected woodwasp larvae are not killed, but rather, the nematode 

reproduces inside the larval stages and infects the eggs of the adult 

female before she emerges from a tree. The nematode is effective in 

controlling Sirex woodwasp because it sterilizes the female but does not 

affect her flying ability, thus allowing her to disperse nematodes widely.

http://na.fs.fed.us/spfo/pubs/pest_al/sirex_woodwasp/sirex_woodwasp.

htm; a pest alert fact sheet of the USDA Forest Service on identification 

and biology.

http://www.invasivespeciesinfo.gov/animals/sirexwasp.shtml; a list of 

websites about Sirex noctilio.

http://www.massnrc.org/pests/pestFAQsheets/european%20woodwasp.

htm; a fact sheet of the University of Massachusetts, including links to 

key sites for further information.

http://www.aphis.usda.gov/plant_health/plant_pest_info/sirex/

downloads/sirexfungus.pdf; a fact sheet on Amylostereum areolatum.

Bedding, R.A. and E.T. Iede. 2005. Application of Beddingia siricidicola

for Sirex woodwasp control. In: Nematodes as Biocontrol Agents. CAB 

International, Cambridge: 385-399.

Long, S.J., D.W. Williams, and A.E. Hajek. 2009. Sirex species 

(Hymenoptera: Siricidae) and their parasitoids in Pinus sylvestris in 

eastern North America. The Canadian Entomologist 14: 153-157.

Dodds, K.J., P. de Groot, and D.A. Orwig. 2010. The impact of Sirex 

noctilio in Pinus resinosa and Pinus sylvestris stands in New York and 

Ontario. The Canadian Journal of Forest Research 40: 212-223.

Slippers, B., P. DeGroot and M.J. Wingfield (eds.). The Sirex Woodwasp 

and its Fungal Symbiont; Research and Management of a Worldwide 

Invasive Pest. Springer Pub. In press.

Schiff, N.M., H. Goulet, D.R. Smith, C. Boudreault, A.D. Wilson, and 

B.E. Scheffler. 2011. Siricidae (Hymenoptera: Siricoidea) of the Western 

Hemisphere. Canadian Journal of Arthropod Identification. In press.

Web Links for Information 

on Sirex Woodwasp

Articles
A Photographic Guide 689

189. Asian Chestnut Gall Wasp, Drycosmus kuriphilus Yasumatsu 

(Hymenoptera: Cynipidae)

Orientation to Pest The Asian chestnut gall wasp, Drycosmus kuriphilus Yasumatsu, is a 

gall making cynipid that is specific to chestnut (Castanea spp.). The gall 

wasp is native to China but invasive in many countries around the world, 

including parts of the United States. Galling disrupts shoot and twig 

growth, impedes normal flowering, and weakens infested trees. Adult 

females (there are no males) emerge from galls in early to mid summer 

and lay several eggs in each chestnut bud they attack. Eggs hatch in mid 

to late summer, and young larvae feed a little and then overwinter in 

the infested buds. When buds begin to grow in spring, galls are formed. 

Galls have one to several chambers, each with a developing gall wasp 

larva. Larvae eat the tissue within the galls and pupate there. New gall 

wasps emerge soon after. After adults emerge, galls turn brown and 

woody and may remain on the tree for several years and are a clear sign 

of infestation. In China, pest outbreaks occur about every 10 years and 

last 2-3 years. There is one generation per year.

This species is specific to species of chestnuts (Castanea). 

Asian chestnut gall wasp is native to China, but is also present in Korea, 

Japan, Nepal, Europe (Italy, France, Slovenia, Hungary, Switzerland, and 

Croatia) and the United States as an invasive pest.

Hosts Commonly Attacked

Distribution

Figure 1. Distribution of 

the chestnut gall wasp, 

Drycosmus kuriphilus, 

in the United States. 

(Ignazio Graziosi)

Images of Chestnut 

Gall Wasp

Figure 2. Adult of Asian 

chestnut gall wasp. 

(Lynne Rieske)
690 Forest Pest Insects in North America:

Images of Chestnut 

Gall Wasp (continued)

Figure 3. Young gall 

of Asian chestnut gall 

wasp in spring (top) 

and old gall after wasp 

emergence (bottom), 

which may remain on 

trees for several years. 

(Both photos: Lynne 

Rieske)

Figure 4. Interior view 

of gall in cross section, 

showing multiple 

chambers and one gall 

wasp pupa. (Melanie 

Sprinkle, Bugwood.org)

Figure 5.View of 

old galls on leafless 

chestnut tree in winter. 

(Lynne Rieske)
A Photographic Guide 691

Important Biological Control 

Agents Related to this 

Pest Species

Classical biological control programs focusing on the parasitoid Torymus 

sinensis Kamijo (Hymenoptera: Torymidae) have been implemented in 

several countries, including Japan and the United States. Several native 

species also utilize the gall wasp as a host.

http://www.eppo.org/QUARANTINE/insects/Dryocosmus_kuriphilus/

DS_Dryocosmus_kuriphilus.pdf; extensive document of EPPO 

(European quarantine organization) on many aspects of the species’ 

biology.

http://www.agroscope.admin.ch/data/publikationen/1304403002_Aebi_

A_Paper_Dryocosmus_Kuriphilus_01-2011.pdf; an extensive document 

on this species and its biological control in Switzerland.

Moriya, S., K. Inoue, A. Otake, M. Shiga, and M. Mabuchi. 1989. 

Decline of the chestnut gall wasp population, Dryocosmus kuriphilus

Yasumatsu (Hymenoptera, Cynipidae) after the establishment of Torymus 

sinensis Kamijo (Hymenoptera, Torymidae). Applied Entomology and 

Zoology 24: 231-233.

Aebi, A., K. Schonrogge, G. Melika, A. Quacchia, A. Alma, and G.N. 

Stone. 2007. Native and introduced parasitoids attacking the invasive 

chestnut gall wasp Dryocosmus kuriphilus. Bulletin of the European and 

Mediterranean Plant Protection Organization (EPPO Bulletin) 37: 

166-171.

Cooper, W.R. and L.K. Rieske. 2007. Community associates of an exotic 

gallmaker, Dryocosmus kuriphilus (Hymenoptera: Cynipidae), in eastern 

North America. Annals of the Entomological Society of America 100: 

236-244.

Cooper, W.R. and L.K. Rieske. 2007. Review of the historic and current 

status of the Asian chestnut gall wasp in North America. Journal of the 

American Chestnut Foundation 11: 26-33.

Rieske, L.K. 2007. Success of an exotic gallmaker, Dryocosmus 

kuriphilus, on chestnut in the USA: a historical account. Bulletin of the 

European and Mediterranean Plant Protection Organization (EPPO 

Bulletin) 37: 172-174.

Web Links for Information 

on Chestnut Gall Wasp

Articles
692 Forest Pest Insects in North America:

190. Spruce Spider Mite, Oligonychus ununguis (Jacobi) (Acari: 

Tetranychidae)

Orientation to Pest Spruce spider mite, Oligonychus ununguis (Jacobi), is a cosmopolitan 

spider mite of uncertain origin associated with spruce (Picea) and other 

conifers. All life stages (egg, immature stages, adult) occur together on 

the host foliage, which is webbed over as infestation grows. Winter is 

passed in the egg stage. Multiple generations occur per year. Outbreaks 

are often induced by the use of pesticides but may occur naturally in 

dry years. Outbreaks are more common on young trees, on which mites 

prefer older foliage in the interior of the tree.

This mite feeds on Colorado (Picea pungens Engelm.) and white (P. 

glauca [Moench] Voss) spruce, Douglas-fir (Pseudotsuga menzeseii

Mirb.), thuja (Thuja), jack (Pinus banksiana Lamb.) and some other 

pines, eastern hemlock (Tsuga canadensis [L.] Carrière), and larch 

(Larix).

Spruce spider mite is found in many countries around the world, and 

its origin in unknown. Its occurrence on introduced plants in countries 

lacking native conifers suggests that at least part of this distribution is 

from invasion, likely due to movement of infested woody nursery stock. 

Hosts Commonly Attacked

Distribution

Images of Spruce

Spider Mite

Figure 1. Adult of spruce 

spider mite, Oligonychus 

ununguis. (Ward Strong, 

BC Ministry of Forests, 

Bugwood.org)

Figure 2. Eggs of spruce spider mite. (Both photos: Ward Strong, BC Ministry of 

Forests, Bugwood.org)
A Photographic Guide 693

Images of Spruce

Spider Mite (continued)

Figure 3. Colony, with 

webbing, of spruce 

spider mite. (USDA 

Forest Service - Region 

4 - Intermountain 

Archive, USDA Forest 

Service, Bugwood.org)

Figure 4. Close up of chlorotic spotting caused by spruce spider mite feeding. 

(John A. Weidhass, Virginia Polytechnic Institute and State University, 

Bugwood.org)
694 Forest Pest Insects in North America:

Images of Spruce

Spider Mite (continued)

Figure 5. Damage on 

white spruce (top) from 

spruce spider mite 

and close up (bottom) 

of webbing from mite. 

(Both photos: Ward 

Strong, BC Ministry of 

Forests, Bugwood.org)

Important Biological Control 

Agents Related to this 

Pest Species

As with most spider mites, control agents are various species of 

predatory mites (Phytoseiidae), predatory gall midges (Cecidomyiidae, 

genus Feltiella), and ladybird beetles (Coccinellidae), which vary by 

region. Destruction of such natural enemies through widespread use 

of pesticides for control of other forest pests can induce outbreaks of 

O. ununguis. This occurred in Montana in the 1950s, for example, 

when DDT was applied over a large area for control of western spruce 

budworm (Choristoneura occidentalis Freeman). Such problems are 

most likely in plantations, seed orchards, or Christmas tree farms that are 

regularly treated for various insect pests.
A Photographic Guide 695

Web Links for Information 

on Spruce Spider Mite

http://imfc.cfl.scf.rncan.gc.ca/insecte-insect-eng.asp?geID=136; fact 

sheet of Natural Resources Canada.

http://wiki.bugwood.org/Oligonychus_ununguis; Bugwood Wiki 

factsheet on biology and control.

http://ento.psu.edu/extension/christmas-trees/information/pest-factsheets/Spspidermiteent069.pdf/view; Pennsylvania Department of 

Agriculture circular on control of spruce spider mite.

Löyttyniemi, K. and K. Heliövaara. 1991. Effect of forest fertilization 

on the spruce spider mite Oligonychus ununguis (Jacobi) (Acarina, 

Tetranychidae). Acarologia 32: 139-143.

Shrewsbury, P.M. and M.R. Hardin. 2003. Evaluation of predatory 

mite (Acari: Phytoseiidae) releases to suppress spruce spider mites, 

Oligonychus ununguis (Acari: Tetranychidae), on juniper. Journal of 

Economic Entomology 96: 1675-1684. 

Articles
696 Forest Pest Insects in North America:
A Photographic Guide 697

1. Pear thrips, Taeniothrips inconsequens: Ken Raffa, raffa@entomology.wisc.edu

2. Introduced basswood thrips, Thrips calcaratus: Ken Raffa, raffa@entomology.wisc.edu

3. Redbanded thrips, Selenothrips rubrocinctus: Howard Frank, jhfrank@ufl.edu

4. Slash pine flower thrips, Gnophothrips fuscus: Howard Frank, jhfrank@ufl.edu

5. Northern walkingstick, Diapheromera femorata: Howard Frank, jhfrank@ufl.edu

6. Oak lace bug, Corythucha arcuata: Paula Shrewsbury, pshrewsbury@umd.edu

7. Sycamore lace bug, Corythucha ciliata: Paula Shrewsbury, pshrewsbury@umd.edu

8. Shield-backed pine seed bug, Tetyra bipunctata: Jean Turgeon, jean.turgeon@nrcan-rncan.gc.ca

9. Leaffooted pine seed bug, Leptoglossus corculus: Dan Miller, dmiller03@fs.fed.us

10. Royal palm bug, Xylastodoris luteolus: Howard Frank, hfrank@ufl.edu

11. Saratoga spittlebug, Aphrophora saratogensis: Ken Raffa, raffa@entomology.wisc.edu

12. Pine spittlebug, Aphrophora parallela: Ken Raffa, raffa@entomology.wisc.edu

13. Thorn bug, Umbonia crassicornis: Howard Frank, jhfrank@ufl.edu

14. Periodical cicada, Magicicada septendecim: Paula Shrewsbury, pshrewsbury@umd.edu

15. Eastern spruce gall adelgid, Adelges abietis: Scott Salom, salom@vt.edu

16. Balsam woolly adelgid, Adelges piceae: Mike Montgomery, michaelemontgomery@fs.fed.us

and Scott Salom, salom@vt.edu

17. Hemlock woolly adelgid, Adelges tsugae: Scott Salom, salom@vt.edu

18. Cooley spruce gall adelgid, Adelges cooleyi: Scott Salom salom@vt.edu

19. Pine bark adelgid, Pineus strobi: Scott Salom, salom@vt.edu

20. Pine leaf adelgid, Pineus pinifoliae: Scott Salom, salom@vt.edu

21. White pine aphid, Cinara strobi: Mike Montgomery, michaelemontgomery@fs.fed.us

22. Woolly elm aphid, Eriosoma americanum: Mike Montgomery, michaelemontgomery@fs.fed.us

23. Woolly beech aphid, Phyllaphis fagi: Mike Montgomery, michaelemontgomery@fs.fed.us

24. Tuliptree aphid, Illinoia liriodendri: Mike Montgomery, michaelemontgomery@fs.fed.us

25. Norway maple aphid, Periphyllus lyropictus: Mike Montgomery, michaelemontgomery@fs.fed.us

26. Linden aphid, Eucallipterus tiliae: Mike Montgomery, michaelemontgomery@fs.fed.us

27. Spruce aphid, Elatobium abietinum: Ann Lynch, alynch@LTRR.arizona.edu

28. Beech scale, Cryptococcus fagisuga: Ben Normark, bnormark@psis.umass.edu

29. Gillette’s eriococcin, Eriokermes gillettei (= Eriococcus gillettei): Ben Normark, 

bnormark@psis.umass.edu

30. Pine bast scale, Matsucoccus matsumurae: Ben Normark, bnormark@psis.umass.edu

31. Tuliptree scale, Toumeyella liriodendri: Ben Normark, bnormark@psis.umass.edu

32. Pine tortoise scale, Toumeyella parvicornis: Steve Clarke, sclarke@fs.fed.us

33. Tessellated scale, Eucalymnatus tessellatus: Ben Normark, bnormark@psis.umass.edu 

Acknowledgments

We thank the following for their review of the species listed:
698 Forest Pest Insects in North America:

34. Elongate hemlock scale, Fiorinia externa: Kris Abell, kabell@psis.umass.edu

35. Oystershell scale, Lepidosaphes ulmi: Ben Normark, bnormark@psis.umass.edu

36. San José scale, Diaspidiotus perniciosus: Ben Normark, bnormark@psis.umass.edu

37. Willow scale, Diaspidiotus gigas: Rob Progar, rprogar@fs.fed.us

and Ben Normark, bnormark@psis.umass.edu

38. Camphor scale, Pseudaonidia duplex: Ben Normark, bnormark@psis.umass.edu

39. Coconut scale, Aspidiotus destructor: Ben Normark, bnormark@psis.umass.edu

40. Florida red scale, Chrysomphalus aonidum: Ben Normark, bnormark@psis.umass.edu

41. Magnolia white scale, Pseudaulacaspis cockerelli: Ben Normark, bnormark@psis.umass.edu

42. White peach scale, Pseudaulacaspis pentagona: Ben Normark, bnormark@psis.umass.edu

43. Citrus whitefly, Dialeurodes citri: Howard Frank, jhfrank@ufl.edu

44. The mealybug Oracella acuta: Steve Clarke, sclarke@fs.fed.us

45. Cottonwood leaf beetle, Chrysomela scripta: David Coyle, dcoyle@warnell.uga.edu

46. Imported willow leaf beetle, Plagiodera versicolora: Paula Shrewsbury, pshrewsbury@umd.edu

47. Elm leaf beetle, Xanthogaleruca luteola: Steve Dreistadt, shdreistadt@ucdavis.edu

48. Larger elm leaf beetle, Monocesta coryli: Steve Dreistadt, shdreistadt@ucdavis.edu

49. Giant palm weevil, Rhynchophorus cruentatus: Mark Hoddle, mark.hoddle@ucr.edu

50. Red palm weevil, Rhynchophorus ferrugineus: Mark Hoddle, mark.hoddle@ucr.edu

51. Pales weevil, Hylobius pales: Ken Raffa, raffa@entomology.wisc.edu

52. Pine root collar weevil, Hylobius radicis: Ken Raffa, raffa@entomology.wisc.edu

53. Pitch-eating weevil, Pachylobius picivorus: Ken Raffa, raffa@entomology.wisc.edu

54. White pine weevil, Pissodes strobi: Ken Raffa, raffa@entomology.wisc.edu

55. Eastern pine weevil, Pissodes nemorensis: Ken Raffa, raffa@entomology.wisc.edu

56. Whitefringed beetles, Naupactus spp.: Ben Normark, bnormark@psis.umass.edu

57. Yellow-poplar weevil, Odontopus calceatus: David Coyle, dcoyle@warnell.uga.edu

58. Native elm bark beetle, Hylurgopinus ru ipes: Steve Katovitch, skatovich@fs.fed.us

and Bob Rabaglia, brabaglia@fs.fed.us

59. Smaller European elm bark beetle, Scolytus multistriatus: Roger Fuester, 

Roger.Fuester@ars.usda.gov

60. Spruce beetle, Dendroctonus ru ipennis: Ann Lynch, alynch@LTRR.arizona.edu

61. Black turpentine beetle, Dendroctonus terebrans: Ron Billings, rbillings@tfs.tamu.edu

62. Eastern larch beetle, Dendroctonus simplex: Robert Haack, rhaack@fs.fed.us

63. Southern pine beetle, Dendroctonus frontalis: Ron Billings, rbillings@tfs.tamu.edu

64. Western pine beetle, Dendroctonus brevicomis: Andy Eglitis, aeglitis@fs.fed.us

65. Jeffrey pine beetle, Dendroctonus jeffreyi: Patrick Shea, pshea@wildlifeheritage.org 

Acknowledgments (continued)

We thank the following for their review of the species listed:
A Photographic Guide 699

66. Mountain pine beetle, Dendroctonus ponderosae: Barbara Bentz, bbentz@fs.fed.us and 

Patrick Shea, pshea@wildlifeheritage.org

67. Douglas-fir beetle, Dendroctonus pseudotsugae: connie mehmel, cmehmel@fs.fed.us

68. Engraver beetle, Ips typographus: Fredrik Schlyter, fredrik.schlyter@ltj.slu.se

69. Pine engraver beetle, Ips pini: Ron Billings, rbillings@tfs.tamu.edu

70. Southern pine engraver, Ips grandicollis: Ron Billings, rbillings@tfs.tamu.edu

71. Six-spined Ips, Ips calligraphus: Ron Billings, rbillings@tfs.tamu.edu

72. Small southern pine engraver, Ips avulsus: Ron Billings, rbillings@tfs.tamu.edu

73. Silver fir beetle, Pseudohylesinus sericeus: Ron Billings, rbillings@tfs.tamu.edu

and Bill Ciesla, WCiesla@aol.com

74. Fir engraver, Scolytus ventralis: Ann Lynch, alynch@LTRR.arizona.edu

75. Columbian timber beetle, Corthylus columbianus: Howard Frank, jhfrank@ufl.edu

76. Ambrosia beetles, Xyleborus spp.: Jim Hanula, jhanula@fs.fed.us

77. Redbay ambrosia beetle, Xyleborus glabratus: Jim Hanula, jhanula@fs.fed.us

78. Walnut twig beetle, Pityophthorus juglandis: Bud Mayfield, amayfield02@fs.fed.us

79. Striped ambrosia beetle, Trypodendron lineatum: Jim Hanula, jhanula@fs.fed.us

80. Black twig borer, Xylosandrus compactus: Jim Hanula, jhanula@fs.fed.us

81. Larger pine shoot beetle, Tomicus piniperda: Robert Haack, rhaack@fs.fed.us

82. White pine cone beetle, Conophthorus coniperda: Steve Katovich, skatovich@fs.fed.us

83. Lodgepole cone beetle, Conophthorus ponderosae: Ward Strong, ward.strong@gov.bc.ca 

85. May and June beetles, Phyllophaga spp.: Steve Katovich, skatovich@fs.fed.us

86. Black vine weevil, Otiorhynchus sulcatus: Lance Osborne, lsosborn@ufl.edu

87. Strawberry root weevil, Otiorhynchus ovatus: Lance Osborne, lsosborn@ufl.edu

88. Japanese beetle, Popillia japonica: Lance Osborne, lsosborn@ufl.edu

89. Two-lined chestnut borer, Agrilus bilineatus: Bob Haack, rhaack@fs.fed.us

90. Bronze birch borer, Agrilus anxius: Bob Haack, rhaack@fs.fed.us

91. Emerald ash borer, Agrilus planipennis: Jian Duan, Jian.Duan@ars.usda.gov

92. Goldspotted oak borer, Agrilus auroguttatus: Tom Coleman, twcoleman@fs.fed.us

93. Soapberry borer, Agrilus prionurus: Ron Billings, rbillings@tfs.tamu.edu

94. Hickory spiral borer, Agrilus torquatus: Matt Ginzel, mginzel@purdue.edu

95. Flatheaded appletree borer, Chrysobothris femorata: Tom Coleman, twcoleman@fs.fed.us

96. Red oak borer, Enaphalodes rufulus: Fred Stephen, fstephen@uark.edu

97. Black fir sawyer beetle, Monochamus urussovi: Mike Montgomery, michaelemontgomery@fs.fed.us

98. Japanese pine sawyer, Monochamus alternatus: Mike Montgomery, michaelemontgomery@fs.fed.us

Acknowledgments (continued)

We thank the following for their review of the species listed:
700 Forest Pest Insects in North America:

99. Asian longhorned beetle, Anoplophora glabripennis: Rhonda Santos, Rhonda.J.Santos@aphis.usda.gov 

100. Poplar borer, Saperda calcarata: Steve Katovich, skatovich@fs.fed.us 

102. Cottonwood borer, Plectrodera scalator: David Coyle, dcoyle@warnell.uga.edu 

103. Banded hickory borer, Knulliana cincta: Jon Sweeney, Jon.Sweeney@NRCan-RNCan.gc.ca 

104. Locust borer, Megacyllene robiniae: Jon Sweeney, Jon.Sweeney@NRCan-RNCan.gc.ca 

105. White oak borer, Goes tigrinus: Matt Ginzel, mginzel@purdue.edu 

and Jon Sweeney, Jon.Sweeney@NRCan-RNCan.gc.ca 

106. Whitespotted sawyer, Monochamus scutellatus: Jean Turgeon, jean.turgeon@nrcan-rncan.gc.ca 

107. Bagworm, Thyridopteryx ephemeraeformis: Marc Rhainds, mrhainds@nrcan.gc.ca 

108. Birch casebearer, Coleophora serratella: (no outside reviewer) 

109. Larch casebearer, Coleophora laricella: Roger Ryan, jandrryan@q.com 

110. Pecan cigar casebearer, Coleophora laticornella: (no outside reviewer) 

111. Oak skeletonizer, Bucculatrix ainsliella: Erik van Nieukerken, Nieukerken@naturalis.nnm.nl 

112. Palm leaf skeletonizer, Homaledra sabalella: Howard Frank, jhfrank@ufl.edu 

113. Mimosa webworm, Homadaula anisocentra: Robert Childs, rchilds@psis.umass.edu 

114. Lodgepole needleminer, Coleotechnites milleri: (no outside reviewer) 

115. Banded ash clearwing, Podosesia aureocincta: Matt Ginzel, mginzel@purdue.edu 

116. Red oak clearwing borer, Paranthrene simulans: Matt Ginzel, mginzel@purdue.edu 

and Tom Coleman, twcoleman@fs.fed.us 

117. Persimmon borer, Sannina uroceriformis: Matt Ginzel, mginzel@purdue.edu 

118. Poplar clearwing borer, Paranthrene dollii: David Coyle, dcoyle@warnell.uga.edu 

119. Carpenterworm, Prionoxystus robiniae: Marvin Harris, m-harris@tamu.edu 

and Brytten Steed, bsteed@fs.fed.us 

120. Pecan carpenterworm, Cossula magnifica: Marvin Harris, m-harris@tamu.edu 

121. Spruce budworm, Choristoneura fumiferana: Lisa Lumley, Lisa.Lumley@rncan-nrcan.gc.ca 

122. Jack pine budworm, Choristoneura pinus pinus: Lisa Lumley, Lisa.Lumley@rncan-nrcan.gc.ca 

123. Large aspen tortrix, Choristoneura conflictana: Lisa Lumley, Lisa.Lumley@rncan-nrcan.gc.ca 

124. Sugar pine tortrix, Choristoneura lambertiana: Lisa Lumley, Lisa.Lumley@rncan-nrcan.gc.ca 

125. Western spruce budworm, Choristoneura occidentalis: Lisa Lumley, Lisa.Lumley@rncan-nrcan.gc.ca 

126. Spruce bud moth, Zeiraphera canadensis: Jean Bev Turgeon, jturgeon@nrcan.gc.ca 

127. Cottonwood twig borer, Gypsonoma haimbachiana: David Coyle, dcoyle@warnell.uga.edu 

129. Oak leafroller, Archips semiferanus: Todd Gilligan, tgilliga@gmail.com 

130. Longleaf pine seedworm, Cydia ingens (= Lapeyresia ingens): Todd Gilligan, tgilliga@gmail.com 

131. European pine tip moth, Rhyacionia buoliana: Darrell Ross, darrell.ross@oregonstate.edu 

Acknowledgments (continued)

We thank the following for their review of the species listed:
A Photographic Guide 701

132. Nantucket pine shoot moth, Rhyacionia frustrana: Jim Lashomb, lashomb@rci.rutgers.edu 

and Darrell Ross, darrell.ross@oregonstate.edu 

133. Pitch pine tip moth, Rhyaciona rigidana: Darrell Ross, darrell.ross@oregonstate.edu 

134. Southwestern pine tip moth, Rhyaciona neomexicana: Darrell Ross, darrell.ross@oregonstate.edu 

135. Eastern pine shoot borer, Eucosma gloriola: Jean Turgeon, jean.turgeon@nrcan-rncan.gc.ca 

136. Lodgepole cone moth, Eucosma rescissoriana: Ward Strong, ward.strong@gov.bc.ca 

137. Western pine shoot borer, Eucosma sonomana: Darrell Ross, darrell.ross@oregonstate.edu 

138. Douglas-fir cone moth, Barbara colfaxiana: Ward Strong, ward.strong@gov.bc.ca 

139. Pine webworm, Pococera robustella: Bud Mayfield, amayfield02@fs.fed.us 

140. Zimmerman pine moth, Dioryctria zimmermani: Amanda Roe, amandaroe5@gmail.com 

141. Fall cankerworm, Alsophila pometaria: Brytten Steed, bsteed@fs.fed.us 

142. Spring cankerworm, Paleacrita vernata: Brytten Steed, bsteed@fs.fed.us 

143. Eastern hemlock looper, Lambdina fiscellaria fiscellaria: Darrell Ross, darrell.ross@oregonstate.edu 

144. Western hemlock looper, Lambdina fiscellaria lugubrosa: Darrell Ross, darrell.ross@oregonstate.edu 

145. Greenstriped forest looper, Melanolophia imitata: (no outside reviewer) 

146. Saddleback looper, Ectropis crepuscularia: (no outside reviewer) 

147. Spearmarked black moth, Rheumaptera hastata: (no outside reviewer) 

148. Elm spanworm, Ennomos subsignarius: Peggy Dixon, peggy.dixon@agr.gc.ca, 

Heidi Fry, heidircf@gmail.com and Krista Ryall, Krista.Ryall@NRCan-RNCan.gc.ca 

149. Winter moth, Operophtera brumata: Joe Elkinton, elkinton@psis.umass.edu 

150. Bruce spanworm, Operophtera bruceata: Joe Elkinton, elkinton@psis.umass.edu 

151. Forest tent caterpillar, Malacosoma disstria (Lasiocampidae): Joe Elkinton, elkinton@psis.umass.edu 

152. Eastern tent caterpillar, Malacosoma americanum (Lasiocampidae): Joe Elkinton, elkinton@psis.umass.edu 

153. Siberian moth, Dendrolimus sibiricus: Mike Montgomery, michaelemontgomery@fs.fed.us 

154. Pinkstriped oakworm, Anisota virginiensis (Saturniidae): Toby Petrice, tpetrice@fs.fed.us 

155. Orangestriped oakworm, Anisota senatoria (Saturniidae): Rose Hiskes, Rose.Hiskes@po.state.ct.us 

and Toby Petrice, tpetrice@fs.fed.us 

156. Pandora moth, Coloradia pandora: Darrell Ross, darrell.ross@oregonstate.edu 

157. European gypsy moth, Lymantria dispar (Lymantriidae): Roger Fuester, Roger.Fuester@ars.usda.gov 

158. Asian pink moth, Lymantria mathura: Roger Fuester, Roger.Fuester@ars.usda.gov 

159. Nun moth, Lymantria monacha (Lymantriidae): Melody Keena, mkeena@fs.fed.us 

160. Browntail moth, Euproctis chrysorrhoea (Lymantriidae): Joe Elkinton, elkinton@ent.umass.edu 

161. Pine tussock moth, Dasychira pinicola (Lymantriidae): Steve Katovich, skatovich@fs.fed.us 

162. White-marked tussock moth, Orgyia leucostigma (Lymantriidae): Robert Johns, Rob.Johns@NRCan.gc.ca 

Acknowledgments (continued)

We thank the following for their review of the species listed:
702 Forest Pest Insects in North America:

163. Douglas-fir tussock moth, Orgyia pseudotsugata: Ann Lynch, alynch@LTRR.arizona.edu

164. Poplar tentmaker, Clostera inclusa: David Coyle, dcoyle@warnell.uga.edu

165. Saddled prominent, Heterocampa guttivitta (Notodontidae): Dave Wagner, david.wagner@uconn.edu

166. Walnut caterpillar, Datana integerrima: Dave Wagner, david.wagner@uconn.edu

167. Variable oak leaf caterpillar, Lochmaeus manteo (Notodontidae): Joe Pase, jpase@tfs.tamu.edu

168. Fall webworm, Hyphantria cunea (Arctiidae): Bud Mayfield, amayfield02@fs.fed.us

169. Arborvitae leafminer, Argyresthia thuiella: Paul Opler, paulopler@comcast.net

170. Pine needle sheathminer, Zelleria haimbachi: Ward Strong, Ward.Strong@gov.bc.ca

171. Pine butterfly, Neophasia menapia: Don Scott, dwscott@fs.fed.us

172. Balsam gall midge, Paradiplosis tumifex (Cecidomyiidae): Rick West, reely.west@nl.rogers.com

173. Poplar leafcurl midge, Prodiplosis morrisi (Cecidomyiidae): Brytten Steed, bsteed@fs.fed.us

174. Douglas-fir needle midge, Contarinia pseudotsugae (Cecidomyiidae): Ward Strong, 

Ward.Strong@gov.bc.ca

175. Pine false webworm, Acantholyda erythrocephala (Pamphiliidae): Barry Lyons,

Barry.Lyons@NRCan-RNCan.gc.ca

176. Redheaded pine sawfly, Neodiprion lecontei (Diprionidae): Bud Mayfield, amayfield02@fs.fed.us

177. Swaine jack pine sawfly, Neodiprion swainei (Diprionidae): Chris MacQuarrie,

Christian.MacQuarrie@NRCan-RNCan.gc.ca

178. European pine sawfly, Neodripion sertifer (Diprionidae): Barry Lyons, Barry.Lyons@NRCan-RNCan.gc.ca

179. Virginia pine sawfly, Neodipirion pratti pratti (Diprionidae): Chris MacQuarrie,

Christian.MacQuarrie@NRCan-RNCan.gc.ca

180. Hemlock sawfly, Neodiprion tsugae: Chris MacQuarrie, Christian.MacQuarrie@NRCan-RNCan.gc.ca

181. Introduced pine sawfly, Diprion similis: Barry Lyons, Barry.Lyons@NRCan-RNCan.gc.ca

182. European spruce sawfly, Gilpinia hercyniae: Chris MacQuarrie,

Christian.MacQuarrie@NRCan-RNCan.gc.ca

183. Larch sawfly, Pristiphora erichsonii (Tenthredinidae): Ken Raffa, raffa@entomology.wisc.edu

184. Mountain ash sawfly, Pristiphora geniculata: Rick West, reely.west@nl.rogers.com

185. Yellowheaded spruce sawfly, Pikonema alaskensis: Rob Johns, Rob.Johns@NRCan.gc.ca.

186. Birch leafminer, Fenusa pumila: Richard Casagrande, casa@uri.edu

187. Ambermarked birch leafminer, Profenusa thomsoni: Anna Soper, asoper@psis.umass.edu

188. Sirex woodwasp, Sirex noctilio: Dave Williams, david.w.williams@aphis.usda.gov

189. Asian chestnut gall wasp, Dryocosmus kuriphilus: L.K. Rieske, lrieske@uky.edu

190. Spruce spider mite, Oligonychus ununguis: Ward Strong, Ward.Strong@gov.bc.ca 

Acknowledgments (continued)

We thank the following for their review of the species listed: