A Review of the Insects and

Mites Found on Taxus spp.

With Emphasis on 

Western North America

John D. Lattin

United States

Department of

Agriculture

Forest Service

Pacific Northwest

Research Station

General Technical 

Report

PNW-GTR-433

November 1998
Author JOHN D. LATTIN is professor of entomology, Systematic Entomology Laboratory,

Department of Entomology, Oregon State University, Corvallis, OR 97331-2907.

Work is from a partnership at the H.J. Andrews Experimental Forest, administered 

by the Pacific Northwest Research Station.

Paper originally presented at the International Yew Resources Conference, 

Berkeley, CA, March 12-13, 1993.
Lattin, John D. 1998. A review of the insects and mites found on Taxus spp. with

emphasis on western North America. Gen. Tech. Rep. PNW-GTR-433. Portland, OR:

U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station.

12 p.

Forty-two species of insects and mites found on Taxus are discussed, including all

those known to occur in North America, of which 27 occur in western North America.

Thirty-eight species are phytophagous, and 28 of these have sucking, rather than

chewing, mouth parts. It is suggested that some of the chemical compounds present

in the foliage of different species Taxus select against chewing insects and favor fluidfeeding arthropods.

Keywords: Taxus, yew, insects, mites, host plant association, North America.

Abstract
1 Introduction

2 Phytophagus Arthropods

2 The Mites: Acari 

2 Insects: Insecta

6 Predaceous and Parasitic Arthropods

7 Discussion and Conclusions

8 Acknowledgments

8 References

Contents
Experienced insect collectors, especially lepidopterists, have long known that species

of Taxus have a depauparate insect fauna1 compared to other trees, including other

conifers. A systematic review of the literature supports this general impression.

Southwood (1961) lists only a single species (a moth) occurring on Taxus baccata L.

in Britain. Kennedy and Southwood (1984), in a reanalysis of the numbers of insects

on British trees, revise the figure upwards to six species, including one mite. This

contrasts with hazel (Corylus avellana L.) with 106 species, hawthorne (Crataegus

monogyna Jacq.) with 209 species, and the two native oaks (Quercus spp.) with 423

species combined (Kennedy and Southwood 1984). We lack such detailed information on most of our native U.S. trees, especially western species, including information on associated insects and mites of even the horticultural species and varieties of

yew in the west. Published information on arthropods on the Pacific yew (Taxus 

brevifolia Nutt.) is almost nonexistent (Bolsinger and Jaramillo 1990). Curiously

enough, the earliest published record of an insect on Pacific yew was in 1915–in 

New Jersey! A scale insect was found “on Taxus cuspidata brevifolia growing in a

nursery” (Weiss 1915). DeLeon (1952) observed that T. brevifolia Nutt. supported

fewer species of insects than did the redwoods (Sequoia sempervirens (D.Don)

Endl.), listing only a single species of a scale insect (Aspidiotus hederae [Vallot]) and

stating that it likely was introduced.2

As this study proceeded, and the list of species from different parts of the country 

and the world began to accumulate, the initial assumption of a small fauna on yew

species was supported. Further, a distinct faunal pattern also emerged; most of the

species were sucking rather than chewing arthropods. Large taxa of herbivores, most

of which are chewing, were either completely absent or represented by only a few

species; that is, Lepidoptera,Hymenoptera, most Coleoptera (weevils excepted),

Hemiptera:Heteroptera,and even Diptera. Aside from a few Lepidoptera, several

Coleoptera (one scarab beetle and a few weevils), and one gall-making fly, most

species were found in the Homoptera (an aphid and three families of scale insects).

Several mite species have been documented in the literature, and there are others

known but not yet studied.3 Several phytophagous families of the true bugs

(Hemiptera:Heteroptera) including the Miridae and Pentatomidae have not yet been

documented from any species of Taxus. Many species of Miridae, in particular, are

found on conifers, chiefly on those trees belonging to the family Pinaceae. The same

is true of several large groups of Homoptera–Cicadellidae and Membracidae.

Because so little collecting has been done from most native species of Taxus, other

insects and mites surely await discovery, and some of the taxa mentioned above may

yet be represented in the world fauna of Taxus. Thus far, only a few species are confined to Taxus and virtually all are polyphagous. This paper is part of a worldwide

review now underway of insects and mites associated with all species of Taxus.

1

Personal communication. 1990. Douglas Ferguson, Systematist, 

U.S. Department of Agriculture, Agricultural Research Service, 

Systematic Entomology Laboratory, Beltsville, MD 20705.

2

Aspidiotus hederae [Vallot] is now considered a synonym of 

A. nerii Bouch

3

Personal communication. 1993. G.W. Krantz, Professor of 

Entomology, Oregon State University, Corvallis, OR 97331.

1

Introduction
There is a distinct mite fauna associated with coniferous trees, a fauna that is still relatively unknown. As with the insect fauna, it appears that the mite fauna on Taxus is

reduced in diversity compared to many tree species although it should be recognized

that our knowledge is far from adequate. Thus far, two species of mites have been

identified from yew in the west although others are known to occur but await study.

4 5

Representing the family Eriophyidae, Cecidophyopsis psilaspis (Nalepa), the yew bud

mite, has been known from eastern North America for some time but only recently

has been identified in the west from Taxus brevifolia in the Coast Range and

Cascade Range of Oregon. These mites cause an expanded growth of plant tissues

in the buds and ultimately bud abortion.6 The family Tenuipalpidae contains a

species, Pentamerismus taxi (Haller), that is found at the base of yew needles, often

in considerable numbers. Originally described from Switzerland (Pritchard and Baker

1958), it had been reported earlier from California (Pritchard and Baker 1951) as 

P. morishitai Pritchard and Baker and later synomymized with P. taxi. Species of

Pentamerismus McGregor are found throughout the Holarctic Region on conifers

excluding the Pinaceae. There is a reasonable possibility of finding additional species

of this genus on other western conifers. Another species of mite, Nalepella tsugifoliae

Keifer (Nalepellidae), the hemlock rust mite, is found on Taxus in eastern North

America but has not yet been recorded from western North America (Johnson and

Lyon 1991).

The groups of insects known to occur on different species of yew are discussed

below. The emphasis is on those found on Taxus spp. in western North America.

General information on other insect taxa found in other parts of North America and

other parts of the world are included when considered appropriate, as it seems quite

likely that at least some representatives of these different groups will be found on yew

in western North America.

Beetles (Coleoptera)--The weevils, or Curculionidae, are well represented in the

fauna of Taxus, second only to the scale insects with six species (Johnson and Lyon

1991). As with the scales, most of the weevil species (four) are nonindigenous. The

most important species is the black vine weevil (Otiorhynchus sulcatus (Fabricius)), a

European species introduced into North America at least as early as 1831 (Warner

and Negley 1976). Although flightless, it is now widely distributed in eastern and

western North America. It is a parthenogenetic species–an ideal characteristic for an

invading organism. A serious pest of many ornamental plants (over 140 hosts have

been identified besides Taxus [Warner and Negley 1976]), it also has penetrated into

the native landscape. We found this species as one of 56 nonindigenous species out

of some 3,400 species of arthropods in an old-growth Douglas-fir (Pseudotsuga 

menziesii (Mirb.) Franco) forest in western Oregon (Parsons and others 1991).

2

Insects: Insecta

Phytophagus

Arthropods

The Mites: Acari

4 Personal communication. 1993. G.W. Krantz, Professor of

Entomology, Oregon State University, Corvallis, OR 97331.

5 Unpublished data on file with the author.

6 Personal communication. 1993. G.W. Krantz, Professor of

Entomology, Oregon State University, Corvallis, OR 97331.
Several other species of weevils cited below also were collected. The larvae of O.

sulcatus feed underground on roots and the adults feed on the foliage, producing very

characteristic damage (notching) to the needles. During summer 1992, in a 76-day

period, a single female fed on 40 old needles and 510 new needles of Taxus spp.

(T. brevifolia and T. baccata). It laid 181 eggs during 63 days, and most of these

hatched (see footnote 5). Adult weevils live for several years. Nielsen and Dunlap

(1981) discuss the reproductive potential of this species on different host plants.

Three other species of Otiorhynchus are known to feed on Taxus spp.: O. ovatus

(Linnaeus), the strawberry root weevil, another major insect pest; O. rugifrons

(Gyllenhal); and O. rugosostriatus (Goeze), the rough strawberry weevil (Warner and

Negley 1976, Wilcox and others 1934). All these species are nonindigenous and

widespread, and only O. rugifrons is confined to northeastern North America

(Newfoundland and Nova Scotia) (Warner and Negley 1976). The two remaining

species, Nemocestes incomptus (Horn) (raspberry bud weevil or woods weevil) and

Sciopithes obscurus Horn (obscure root weevil) are native to the Pacific Northwest.

They, too, feed on a variety of different hosts (Johnson and Lyon 1991, Wilcox and

others 1934). Some of the weevils discussed above are nocturnal feeders as adults

and thus avoid detection. Even though most species are flightless, their expansion

across the landscape has been impressive. Because of their broad host range, there

is substantial literature on most of these species.

The Scarabaeidae beetle (Maladera castanea (Arrow)), known as the Asiatic garden

beetle, was introduced into eastern North America in 1921 from the Orient (Drooz

1985). The adults feed on yew foliage and the larvae on the roots. It is not known to

occur in western North America. The so-called rain beetles (Scarabaeidae:

Pleocoma spp.) do occur in the Pacific Coast region, and a few of the species occur

in mature, low-elevation coniferous forests where T. brevifolia is found. The life cycle

is very long, with the larvae spending many years in the soil feeding on roots (Ritcher

1958). Although no records exist of Pleocoma feeding on yew, the beetles could be a

potential pest species.

Flies (Diptera)--No species of Diptera has yet been found associated with yew in 

the west, but species of at least three different families are known elsewhere. The

best known species is Taxamyia taxi Inchbaldl, a gall midge (Cecidomyiidae) well

known in Europe where it makes galls on Taxus baccata (Mani 1964, Redfern 1975).

Johnson and Lyon (1991) state that the species might occur in North America but 

has not yet been recognized, perhaps because the damage has been confused 

with that of the yew bud mite (Cecidophyopsis psilaspis (Nalepa)). A species of

Drosophilidae (Drosophila sp.) was reared from the arils of T. baccata in Europe

(Burla and Bachli 1991).

Aphids and scales (Homoptera)--At least one Aphididae is known to occur from 

T. baccata in India; but thus far, no species have been recovered in North America.

Ghosh and others (1969) describe Anocaudus taxus from Khadrala, India. The 

specimens occurred on the roots. Hille Ris Lambers (1973) transferred A. taxus to

the genus Prociphilus Koch when he considered Anocuadus Ghosh, Chakrabarti,

Chowdhuri, and Raychaudhuri a synonym of Prociphilus.

3
Three species of the scale family Coccidae occur on Taxus spp. in North America.

Specimens were determined tentatively as Parthenolecanium corni (Bouché) by 

M. Williams7 from T. brevifolia at two localities in western Oregon by the author. A 

second species (P. fletcheri (Cockerell)), known as the Fletcher scale, was reported

from T. media var. hicksi in Rhode Island by Kerr (1951). Johnson and Lyon (1991)

also record it from Taxus spp. and consider it a major pest of yew. The cottony taxus

scale (Pulvinaria floccifera (Westwood)), also known as the cottony camelia scale, is

widespread across North America, including the Pacific Coast (Drooz 1985). Crawlers

settle on the needles and then move to the twigs, where they overwinter as secondstage nymphs (Johnson and Lyon 1991). This species was reported on T. media var.

hicksi in Rhode Island (Kerr 1951).

The armored scales belonging to the family Diaspididae are well represented on

Taxus spp. in North America. At least 15 species have been reported from the 

United States and Canada, and most are nonindigenous to North America (Dekle

1965; DeLeon 1952; Drooz 1985; Essig 1913; Johnson and Lyon 1991; McKenzie

1956; Rosen 1990a, 1990b). The species thus far found on Taxus spp. include

Aonidiella taxus Lenonardi, Aspidiotus nerii Bouché, A. spinosus Comstock,

Chinoaspis pinifoliae (Fitch), Chrysomphalus dictyospermi (Morgan), C. ficus Ashmead,

Dynaspidiotus britannicus (Newstead), Fiorinia externa Ferris, F. fioriniae (TargioniTozzetti), Hemiberlesia rapax (Comstock), Lepidosaphes beckii (Newman), L. maskelli

(Cockerell), Pseudacaspis cockerelli (Cooley), Quadraspidiotus perniciosus (Comstock),

and Tsugaspidiotus tsugae (Marlatt). Reference to all these species may be found in

the works cited above. Many of these species of scales feed on various hosts, including Taxus. Most are found in the United States on ornamental species and those

grown in cultivated situations. Because most species have been introduced into

North America from Asia and Europe, it is difficult to predict just what would happen

to native species of Taxus growing under natural conditions. Because some scales

do occur on native Taxus, the potential is there; only careful field work throughout the

ranges of our native yews will keep us informed. Attention should be directed to

areas surrounding urban and suburban localities. McClure (1980), and papers cited

therein, provides very interesting information on the dynamics of exotic scale insects

on conifers, including two species discussed here.

Six species of mealybugs (Homoptera:Pseudococcidae) are found on Taxus spp. in

North America (Johnson and Lyon 1991, McKenzie 1967). These insects usually are

found on the foliage and branches. The white, waxy secretions covering their 

bodies are characteristic and give them their common name. Taxonomically, this is 

a difficult group, and many name changes and misidentifications occur. Johnson and

Lyon (1991) suggest that the host plant itself may influence the form of the insect.

4

7 Personal communication. 1993. Professor of Entomology,

Auburn University, Auburn University, AL 36849-5413.
The taxus mealybug (Dysmicoccus wistariae (Green)), known previously as 

D. caspidatae Rau, is the best known species on yew. Reported from Connecticut,

Massachusetts, New Jersey, New York, Ohio, and Pennsylvania, it is the only one of

the six mealybug species not known to occur in western North America, although it

was included in the key to the species of Dysmicoccus for convenience by McKenzie

(1967). The monograph of California mealybugs by McKenzie (1967) is an important

reference for the western fauna. A second species, Pseudococcus maritimus

(Ehrhorn), is a pest of Taxus in Ohio (Neiswander 1949) but is not yet known from

yew in California, although the insect does occur there (McKenzie 1967). The

species is more commonly known as the grape mealybug. Pseudococcus comstocki

(Kuwana), introduced into eastern North America from Asia, is reported on Taxus

(Johnson and Lyon 1991). This mealybug also was introduced into California and is

reported by McKenzie (1967) from that State; he did not record the species at that

time from Taxus.

8

Three additional species of Pseudococcus are known from Taxus spp. in the west

(McKenzie 1967). Pseudococcus affinis (Essig), the obscure mealybug, known previously as P. obscurus Essig, is commonly found on Taxus (Johnson and Lyon 1991).

Pseudococcus fragilis Brain is reported from T. baccata in California where it was

believed to have been introduced from Australia (McKenzie 1967). The final species,

P. longispinus (Tarioni-Tozzetti), the long-tailed mealybug, is reported from Florida,

Texas, and California (Johnson and Lyon 1991). McKenzie (1967) records it from

California on T. baccata var. washingtonii.

Moths (Lepidoptera)--Although Lepidoptera are usually important foliage feeders 

in forested ecosystems, including conifers, it is remarkable that to date only three

species have been reported from Taxus in North America (several other species are

known from Europe). The Geometridae Cladara limitaria (Walker), the yellow-lined

conifer looper (known for many years as Nyctobia limitaria), is found in eastern and

western Canada and the Northern United States (Martineau 1984). As the name

suggests, it feeds on other hosts besides Taxus (Butler and Kondo 1991; Evans 1983;

Furniss and Carolin 1977; Hodges 1983; Prentice 1963; Rose and Lindquist 1977,

1980). Only Prentice (1963) reports the species from Taxus and without specific

locality or species of yew. It is considered a summer feeding species (Rose and

Lindquist 1977) and uncommon (Evans 1983). Cladara limitaria is found in British

Columbia (Prentice 1963) and Oregon.9 Two additional species of Geometridae have

been reported from Europe on yew: Peribatodes rhomboidana Schiff. and Deileptenia

ribeata Cl. (Forster and Wohlfarht 1981).

5

8 This citation is easily overlooked as it is found as an addendum

on the unnumbered page of the monograph after p. 525.

9 Personal communication. 1993. Paul Hammond, Research

Associate, Department of Entomology, Oregon State University,

Corvallis, OR 97331.
The Pyralidae Uresiphita reversalis (Guenée), known as the genista caterpillar, is

reported from California (Powell 1992). It feeds on various legumes, chiefly exotic

species like broom and especially French broom (Genista [= Cytisus] monspessulana

[L.]). Powell (1992) also records the caterpillars feeding on nonleguminous plants as

well, including Taxus sp. and Buddleia sp. (Loganiaceae). Because of the lack of

records before 1930, he suggests that U. reversalis is either an introduced or adventive exotic. According to Powell (1992), it may be native to the southeastern United

States and Mexico, having been described originally as from “North America.” Its first

occurrence in the San Francisco Bay area was in 1966. He states that the species

depends on introduced plants in California and thus may be an exotic or native nonindigenous species in that State.

The Tortricidae Ditula angustiorana (Haworth) is a species introduced from Europe

(Clarke 1930, Freeman 1958, Keifer 1933). It too was long known under a different

combination, Batodes angustiorana (Clarke 1930, Evans 1983, Prentice 1965).

Known from several localities in eastern North America, it also was recovered from

yew in British Columbia (Clarke 1930) and California (Keifer 1933). The species also

was found feeding on holly in British Columbia. MacKay (1962) reports it from

Washington. In Europe it is found on other hosts besides Taxus, including fruit trees

(Bradley and others 1973). Apparently, it is not a common species in North America;

Prentice (1965) considers it a solitary feeder.

The nun moth (Lymantria monacha L.) also has been reported from yew in Europe.

Thus far, this species has not been reported from North America, although the nun

moth is considered a major risk for introduction on raw logs from Siberia (USDA

Forest Service 1991). Winter (1983) reports a species of Blastobasidae (Blastobasis

lignea Walsingham) from yew in Britain.

Beetles (Coleoptera)--Several species of the family Coccinellidae (ladybird beetles)

have been reported feeding on the coccid, Pseudococcus comstocki (Kuwana), in

Ohio by Sluss and Foote (1971). The species mentioned by these authors were

Adalia bipunctata (L.) and Coccinella transversoguttata richardsoni Brown. With several scale insects found on yew species in the west, it is likely that some species of

ladybird beetles will be found feeding on them.

Flies (Diptera)--Sluss and Foote (1971) report on the biology of Leucopsis verticallis

Malloch, a fly of the family Chamaemyiidae whose larva was found to be a predator

of P. comstocki (Kuwana) (Homoptera:Pseudococcidae) living on T. cuspidata Sieb.

and Zucc. var. hicksii Rehd. in Ohio. The same paper contains references to other

predators of the Homoptera.

Wasps (Hymenoptera)--A species of Encyrtidae (Hymenoptera:Chalcidoidea)

belonging to the genus Pseudleptomastix Girault was reared from scale

(Pseudococcus comstocki (Kuwana) (Homoptera:Pseudococcidae)) occurring on 

T. cuspidata var. hicksii in Ohio (Sluss and Foote 1971). It is quite likely that scale

insects found on yew in western North America will be parasitized.

6

Predaceous and

Parasitic Arthropods
Lacewings (Neuroptera)--Sluss and Foote (1971) report larvae of an unidentified

genus and species of the Chrysopidae (lacewings) feeding on P. comstocki (Kuwana)

that occurred on T. cuspidata var. hicksi in Ohio. Although members of the

Neuroptera family Hemerobiidae are more likely to be found on conifers of all types 

in the west, Chrysopidae too are sometimes taken. In addition, we have several

species of snakeflies in the west (Raphidioptera), a group not found in eastern 

North America. Two families occur here, Inocellidae and Raphidiidae; species of 

both families are predacious and potential predators of yew insects.

This brief overview includes information on 42 species of insects and mites: 27 occur

in western North America, 38 are phytophagous, and 4 are parasitoids or predators.

This is a preliminary review, based largely on the widely scattered literature, literature

often tangential to Taxus but with references that include Taxus as one of many hosts

for a given species. Compared to many other host plants, the information about its

fauna is sparse, partly because the fauna is sparse and partly because the tree is, or

rather has been, an obscure understory species.

Intensive field collecting on all the native Taxus species will certainly enlarge the

known fauna. Most of the information we have is based on the literature of Taxus

spp. grown as ornamentals rather than from native stands, with Europe excepted 

(T. baccata). But even there, the tree often is found in domesticated situations. The

manner in which the arthropod records are presented often makes it difficult to know

what species of Taxus is involved because only the generic name is used.

So many of the arthropod species found on Taxus spp. in North America are nonindigenous that it raises other questions about the nature of our native fauna. The

papers by McClure (1977a, 1977b, 1977c, 1978) and McClure and Fergione (1977)

provide a fascinating account of two introduced species of scale insects on hemlock

in eastern North America. Both species, Fiorinia externa and Tsugaspidiotus tsugae,

also occur on Taxus.

Thirty-eight of the insects and mites associated with Taxus are phytophagous, and 28

of these (74 percent) are species with sucking mouth parts. Even though we know

more about exotic species on Taxus in the United States, our fragmentary knowledge

of native U.S. fauna seems to reflect the general taxonomic pattern shown by the

nonindigenous species; that is, a preponderance of sucking rather than chewing

species. Just why sucking taxa should be so well represented and chewing species

so poorly represented is not known. The answer may be found in the chemicals

found in the plant itself, especially in the foliage. Intensive investigations have been

made into the chemical compounds found in all species of Taxus in an attempt to

understand the frequency of the taxanes that are the sources of taxol, so important in

the treatment of cancer. (Chang [1996] presents an interesting account of the general increased interest in yew in Taiwan.) The chemistry of Taxus is very well known.

Contained within this vast literature on the chemical characteristics of the different

species of Taxus are indications of the presence of other compounds, especially the

phytoecdysteroids that interfere with the moulting of some insects (Pipa and others

1990). It is likely that the presence of these compounds in the foliage of the tree

would interfere with development of immature chewing insects, such as caterpillars,

sawflies, and leaf beetles. The few chewing insects that feed on yew foliage, the

7

Discussion and

Conclusions
scarab and especially the weevils, are adults and the larvae of weevils feed on the

roots (Johnson and Lyon 1991). Thus it would seem that the sucking insects may

bypass the defense mechanisms as they feed on the liquid portions of the leaves,

twigs, and branches without macerating the tissues the way chewing insects do.

Further investigations into the role of the chemical constituents of Taxus on the feeding activities of the insects and mites also will clarify the issue of feeding strategies.

As so often is the case, the results of one line of investigation (for example, reduced

fauna found on Taxus spp.) leads to other investigations--the impact of plant compounds on the feeding habits of herbivores. The intensive work on yew because of its

important medicinal qualities has provided interesting ancillary information of value in

other areas of human activity–quite typical of many scientific efforts (Chang 1996).

I dedicate this paper to Dr. Thomas T. Sugihara, chemist, Dean of the College of

Science, Oregon State University, 1981-86, and long-time friend and colleague.

Tom died of cancer on November 30, 1992.

Sincere thanks to my long-time colleague, G.W. Krantz, for his help with the mites; to

S. Scher for his broad knowledge of Taxus; to my son, P.D. Lattin, for insect specimens from Pacific yew; to Anne Christie and R. Lawrence, Kerr Library, for their help

with critical literature; to Cindy Froyd, USDA Forest Service, for interest in arthropods

on yew; and to Colleen MacRae and Jackie Poppleton for their fine work in the preparation of the manuscript. Roy C. Beckwith, Anne Christie, Marcos Kogan, and Jeffrey

C. Miller reviewed the manuscript.

Bolsinger, C.L.; Jaramillo, A.E. 1990. Taxus brevifolia Nutt. Pacific yew. In: Burns,

R.M.; Honkala, B.H., tech. coords. Silvics of North America. Vol. 1, Conifers.

Agric. Handb. 654. Washington, DC: U.S. Department of Agriculture, 

Forest Service: 573-579.

Bradley, J.D.; Tremewan, W.G.; Smith, A. 1973. British tortricoid moths:

Cochylidae and Tortricidae. London: The Ray Society. 251 p.

Burla, H.; Bachli, G. 1991. Notes on rearing drosophilid species from both

cultivated and natural fruits. Mitteilungen der Schweizerischen

Entomologischen Gesellschaft. 64: 45-53.

Butler, L.; Kondo, V. 1991. Macrolepidopterous moths collected by blacklight trap 

at Cooper’s Rock State Forest, West Virginia: a baseline study. Bull. 705.

Morgantown, WV: West Virginia University, Agricultural and Forestry Experiment 

Station. 25 p.

Chang, C. 1996. The changing fortunes of the Taiwan yew. Sinorama. 87: 78-89.

[Published in Taiwan].

Clarke, J.F. 1930. Entomology. In: Report of the Provincial Museum of Natural 

History for the Year 1929. [Victoria, BC]: [Publisher unknown].

8

Acknowledgments

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9
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biology, natural enemies and control. Amsterdam: Elsevier. 383 p. Vol. A.

11
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12
Lattin, John D. 1998. A review of the insects and mites found on Taxus spp.

with emphasis on western North America. Gen. Tech. Rep. PNW-GTR-433.

Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific 

Northwest Research Station. 12 p.

Forty-two species of insects and mites found on Taxus are discussed, including

all those known to occur in North America, of which 27 occur in western North

America. Thirty-eight species are phytophagous, and 28 of these have sucking,

rather than chewing, mouth parts. It is suggested that some of the chemical

compounds present in the foliage of different species Taxus select against

chewing insects and favor fluid-feeding arthropods.

Keywords: Taxus, yew, insects, mites, host plant association, North America.

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