bluuebunny/crossref_metadata_2025 huggingface dataset:
Contextual Chemical Ecology: Male to Male Interactions Influence European Corn Borer1 Male Behavioral Response to Female Sex Pheromone in a Flight Tunnel
Authors: Klun Jerome A. , Graf Jennifer C.
Published: September 2017

The responses of European corn borer, Ostrina nubilalis (Hübner), males in a flight tunnel to sex pheromone, [11-tetradecenyl acetate (97:3, Z:E)] was dependent upon the context in which the males were exposed to the stimulus. Males, held individually in isolation before being exposed to pheromone, flew upwind in the pheromone plume and landed on the pheromone source significantly more often than males caged with other males before exposure to the pheromone. When groups of males were simultaneously exposed to female sex pheromone, they responded, on a permale basis, with significantly more upwind flights to pheromone and intense behavior near the pheromone source than did males exposed to the pheromone individually. Heightened intensity of male response in group flight was independent of whether the males were individually isolated or caged with other males before being exposed to the pheromone. The enhanced behavioral output of males responding to pheromone in groups may represent an evolutionary adaptive advantage in instances where several males are simultaneously pursuing a single calling female.
Transmission of Nuclear Polyhedrosis Virus Prior to Death of Infected Loblolly Pine Sawfly, Neodiprion taedae linearis Ross, on Loblolly Pine
Authors: Young Seth Y.
Published: September 2017

Nuclear polyhedrosis virus (NPV) was transmitted by infected loblolly pine sawfly, Neodiprion taedae linearis Ross, larvae prior to death on loblolly, pine. Third instars reared on pine foliage previously fed upon for 24 h by NPV-infected larvae at densities of 4 and 16 per terminal resulted in up to 69.9 and 93.1% mortality, respectively, in previously unexposed cohorts. Third instars reared on pine foliage wetted with washings from frass of infected larvae also resulted in a high level of mortality. Results suggest that a high level of secondary transmission of NPV occurs before death of primary-infected larvae. This transmission appears to be the result of NPV in the digestive tract released either through regurgitation or in the feces.
Site Quality in Relation to Damage by Locust Borer, Megacyllene robiniae Forster in Black Locust
Authors: Echaves Victor D. , Harman Dan M. , Harman Amy L.
Published: September 2017

Forty-three study sites within eight counties in Maryland were utilized in an investigation of Site Index in relation to attack by the locust borer, Megacyllene robiniae (Forster), on the black locus tree, Robinia pseudoacacia L. In addition, several other factors related to borer attack intensity were tested for relationship with Site Index of black locust. Site Index was found to be negatively correlated with borer tunnels per tree, i.e., sites with higher Site Indices had statistically fewer borer attacks per tree. Positive correlation was also inferred between Site Index, borer attacks, and (1) scarring from previous year's borer attacks, (2) herbaceous biomass within-site, (3) elevation above sea level, (4) soil factors, including pH, %sand, silt, and clay.
Laboratory Studies of the Interactions of Environmental Conditions on the Susceptibility of Green June Beetle (Coleoptera: Scarabaeidae) Grubs to Entomopathogenic Nematodes
Authors: Townsend Monica L. , Johnson Donn T. , Steinkraus Don C.
Published: September 2017

In the laboratory, four nematode species differed significantly in the percentage mortality that each caused in second-instar green June beetles (grubs), Cotinis nitida (L.). Water suspensions of 1,000 infective juveniles (IJ)/one grub/Petri dish each of Heterorhabditis bacteriophora, Steinernema glaseri, and S. feltiae caused 34, 22 and 18% grub mortality, respectively. These values were significantly (P = 0.05) greater than the grub mortality caused by either S. carpocapsae (12%) or the water check (0%) that were similar. Several factors affected third- and fourth-instar susceptibility in the laboratory when exposed to 10,000 S. carpocapsae or H. bacteriophora IJ in 75 g of soil (133 IJ/cm3 soil)/plastic cup. Soil at 30% moisture by weight resulted in significantly more (P= 0.006) dead grubs (6.6%) than at 10% soil moisture (2.8%). Significantly more (P = 0.03) grubs died when at a grub density of 2 grubs/plastic cup (5.6%) than at 1 grub/plastic cup (3.8%). Significantly more (P = 0.01) grubs were killed by either S. carpocapsae and H. bacteriophora at a soil temperature of 25°C (6.5%) than at 12°C (2.8%). There was also a significant interaction of temperature and nematode species. Heterorhabditis bacteriophora killed significantly more (P= 0.02) grubs at 25°C (9.5%) than at 12°C (1.9%) and more than S. carpocapsae killed at either 12°C or 25°C (<3.9%). More virulent nematode strains or species than these four nematode species must be identified if green June beetles are to be controlled by nematodes.
Behavioral Response of Podisus maculiventris (Hemiptera: Pentatomidae) to its Synthetic Pheromone
Authors: Shetty Pragathi N. , Hough-Goldstein Judith A.
Published: September 2017

A wind-tunnel bioassay was used to determine the effect of age and feeding history (starvation) on the response of Podisus maculiventris (Say) to its synthetic pheromone. Starved male and female adults showed positive anemotaxis toward the pheromone source; well-fed insects did not. This supports the hypothesis that P. maculiventris adults use the pheromone as a cue indicating presence of prey, in addition to a mating cue, although a physiological explanation for the lack of response by well-fed insects is also possible. In the presence of the pheromone, fed as well as starved insects increased activities such as extending antennae upwind; fluttering wings; and rubbing antennae, proboscis, forelegs, hindlegs, and abdomen. These activities may indicate stimulation of olfactory receptors on antennae and contact chemoreceptors elsewhere on the body. First- to third-generation offspring of field-collected P. maculiventris showed greater response to the synthetic pheromone compared with individuals from a 2-year-old laboratory colony, indicating the importance of using field-collected insects in behavioral studies. Fifth instars did not respond to the synthetic pheromone in the wind tunnel.
Ovipositional Preference and Distribution of Eggs in Selected Field and Vegetable Crops by Nabis roseipennis (Hemiptera: Nabidae)
Authors: Pfannenstiel R. S. , Yeargan K. V.
Published: September 2017

Hemipteran predator abundance varies significantly among crop species. Ovipositional preference by these predators for specific crops may help explain differences in predator abundance among crops. Ovipositional preferences of Nabis roseipennis Reuter between a preferred standard (soybean) and four crops (corn, tomato, tobacco and squash) were determined in paired-choice tests under greenhouse conditions. Significantly more eggs or egg groups were found in soybean than in corn and tomato. Squash was the only plant preferred for oviposition over soybean. Within-plant distribution of eggs varied among plant species and appeared to be independent of prey distribution. The specific site chosen for oviposition in each plant species apparently was determined by plant physical characteristics, possibly including rind toughness and, for tomato and tobacco, glandular trichome presence and age. Patterns of ovipositional preference were similar to previous observations of field abundance and may be partially responsible for those patterns.
Antagonism between Formulations of Different Bacillus thuringiensis Subspecies in Heliothis virescens and Helicoverpa zea (Lepidoptera: Noctuidae)
Authors: Ameen A. O. , Fuxa J. R. , Richter A. R.
Published: September 2017

Interactions between formulations of the aizawai and kurstaki subspecies of Bacillus thuringiensis Berliner were evaluated by bioassay in Heliothis virescens (F.) and Helicoverpa zea (Boddie). In preliminary experiments, a formulation of subspecies aizawai, Xentari AS®, had significantly (P < 0.05) higher median lethal concentrations (LC50s) in both insect species than formulations based on subspecies kurstaki. Helicoverpa zea was significantly (P < 0.05) more susceptible than H. virescens to one formulation of subspecies kurstaki (Dipel ES®), but the two insects did not differ in susceptibility to Xentari AS® or to a second formulation of subspecies kurstaki (Dipel 6AF®). In H. virescens, Xentari AS® was additive with Dipel 6AF® and significantly (P< 0.05) antagonistic with Dipel ES® and with a third formulation of subspecies kurstaki, Dipel 48A®. In H. zea, Xentari AS® was significantly antagonistic with all three formulations of subspecies kurstaki. This suggests that certain toxin combinations from B. thuringiensis subspecies might not be effective for managing H. virescens and H. zea populations.
Mortality of Tobacco Budworm Larvae (Lepidoptera: Noctuidae) and Emergence of Cotesia marginiventris (Hymenoptera: Braconidae) Exposed to Bacillus thuringiensis and Thiodicarb Alone and in Combination
Authors: Atwood D. W. , Young S. Y. , Kring T. J.
Published: September 2017

Mortality of Heliothis virescens (F.) larvae and emergence of Cotesia marginiventris (Cresson) were evaluated on terminals collected from cotton in fields treated with Bacillus thuringiensis Berliner var. kurstaki and thiodicarb. Tests were conducted using B. thuringiensis and thiodicarb, independently and in combination. Insecticide rates were those recommended for resistance management in Arkansas. Results indicate that neither B. thuringiensis nor thiodicarb, alone or in combination, provided acceptable control of H. virescens larvae (<33%) by day 16. However, thiodicarb and thiodicarb/B. thuringiensis mixtures provided significantly greater control of H. virescens than did B. thuringiensis application alone. In addition, no significant advantage was gained with tank mixtures of B. thuringiensis and thiodicarb as compared to thiodicarb application alone. Parasitization increased early larval mortality (day 2) only in conjunction with the application of B. thuringiensis. Neither insecticide applied independently nor in combination had a significant impact on the emergence of C. marginiventris from H. virescens. Overall, while results indicated unsatisfactory control of H. virescens, findings indicated no detrimental effect on the larval parasitoid population at rates suggested for resistance management.
Survey of Insect Pests in Shelled Corn Stored On-Farm in Kentucky
Authors: Sedlacek John D. , Weston Paul A. , Price Bryan D. , Rattlingourd Patti L.
Published: September 2017

Shelled corn stored in metal bins was sampled for insects on farms in the three westernmost crop reporting districts of Kentucky during 1989 and 1990 to identify pest insects present, determine the relative abundance of insect pests, and determine their geographic distributions. Thirty-six species or species groups were found in this survey. The most abundant insects were maize weevil, Sitophilus zeamais Motschulsky; Angoumois grain moth, Sitotroga cerealella (Olivier); flat grain, rusty grain, and flour mill beetles, Cryptolestes spp.; sawtoothed grain beetle, Oryzaephilus surinamensis (L.); foreign grain beetle, Ahasverus advena (Waltl); red and confused flour beetles, Tribolium spp.; and hairy fungus beetle, Typhaea stercorea (L.). Greater densities and numbers of species were caught later during the storage season and greater numbers were captured from the center versus edges of bins. The unexpectedly high abundance and widespread distribution of maize weevil and Angoumois grain moth suggests that greater care needs to be taken to manage these pests because of direct feeding damage and the resulting increased susceptibility of grain to secondary insect pests (e.g., Cryptolestes spp., sawtoothed grain beetle, Tribolium spp., foreign grain beetle, and hairy fungus beetle, which were commonly found) and fungi.
Performance of the Tobacco Aphid (Homoptera: Aphididae) on Various Host Plants
Authors: Semtner Paul J. , Tilson William M. , Dara Surendra K.
Published: September 2017

The tobacco aphid, Myzus nicotianae Blackman, is a major pest of tobacco in the United States. It was separated from the green peach aphid, M. persicae (Sulzer), and described as a new species in 1987. Information on its host range is limited because the two species are so similar. Therefore, the performance of the tobacco aphid was studied on 28 potential host plants in six families. Numbers of offspring, age at first reproduction, longevity, weight, and percentage reproducing were compared. Tests were conducted on excised leaves or leaf disks maintained in Petri dishes in an environmentally-controlled chamber. Myzus nicotianae reproduced on hosts in the families Asteraceae, Convolvulaceae, Cruciferae, Malvaceae, and Solanaceae, but not on Spinacia in Chenopodiaceae. Myzus nicotianae generally reproduced most quickly, was heaviest, and produced the most nymphs on tobacco, Nicotiana tabacum L., and American black nightshade, Solanum americanum (Solanaceae). Performance also was good on Capsicum and S. dulcamara L. (Solanaceae). Aphids exhibited fair-to-good performance on three species of Ipomoea (Convolvulaceae), Datura, and Physalis (Solanaceae); Raphanus and two species of Brassica (Cruciferae); and Abelmmoschus (Malvaceae). Performance was fair on two species of Ipomoea, three species of Solanum, Lactuca (Asteraceae), and several Brassica. Longevity was short, and very few offspring were produced on Gossypium (Malvaceae) and Lycopersicon (Solanaceae). This study indicates that M. nicotianae does well on several species in five plant families that contain important crop and weed species.
Effects of Repeated Use of Fenoxycarb and Hydramethylnon Baits on Nontarget Ants
Authors: Zakharov A. A. , Thompson L. C.
Published: September 2017

Sites receiving repeated broadcast applications of fenoxycarb and hydramethylnon baits for red imported fire ant, Solenopsis invicta Buren, control were examined for impact of bait treatments on ant diversity in southeastern Arkansas. Ants collected from sugar baits belonged to three subfamilies and 25 species. As compared with checks, native ant species increased on fenoxycarb-treated plots and decreased on hydramethylnon-treated plots. Except for S. invicta, ants within the subfamily Myrmicinae practically disappeared from hydramethylnon-treated plots. Sensitivity of ants in the subfamilies Formicinae and Dolichoderinae to hydramethylnon and fenoxycarb was comparatively low. As a consequence, fenoxycarb shows promise for the integrated management of imported fire ants when broadcast applications are desirable.
Retention of External and Internal Markers by Southern Pine Beetles (Coleoptera: Scolytidae) During Gallery Construction
Authors: Rhodes Douglas J. , Hayes Jane Leslie , Steiner Chris
Published: September 2017

If retained, markers used in mark-release-recapture studies of bark beetle dispersal could provide valuable tools in the determination of post-dispersal fate. Retention of the internal marker rubidium (Rb) and of the external marker fluorescent powder during egg gallery construction, oviposition, and feeding were quantified at intervals from 0 to 96 h by allowing marked Southern pine beetles, Dendroctonus frontalis Zimmermann, to carry out these activities in untreated host material. Significant differences in Rb concentrations were found between fed and unfed Rb-marked beetles at all intervals after 12 h. Unfed Rb-marked beetles were detectable at all intervals, whereas reliable detection of fed Rb-marked beetles declined with time. Over 90% of fed southern pine beetle marked with fluorescent powder were detectably marked after 96 h, while less than 50% of the Rb-marked beetles were detectable after 72 h. Neither marking technique adversely affected the gallery length or number of eggs produced by marked beetles compared to unmarked beetles allowed to excavate for 96 h. Practical aspects of both techniques are considered.
Survey of Parasitoids of the European Corn Borer (Lepidoptera: Pyralidae) in Southwestern Kentucky
Authors: Shanklin D. R. , Johnson D. W. , Townsend L. H.
Published: September 2017

The European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Pyralidae), is a major maize pest throughout the maize-growing regions of the U.S. A survey was conducted to determine the parasitoids of European corn borer in southwestern Kentucky, the major maize producing region in the state. Two species, Lixophaga variabilis (Coquillett) (Diptera: Tachinidae) and Eriobus terebrans Gravenhorst (Hymenoptera: Ichneumonidae), were found. The most abundant species was the native L. variabilis. Only one E. terebrans was collected.
Toxicity of Synthetic Sucrose Esters Against the Tobacco Aphid (Homoptera: Aphididae)
Authors: Xia Yulu , Johnson Albert W. , Chortyk O. T.
Published: September 2017

Four synthetic sucrose esters were evaluated in the laboratory and field to determine their insecticidal activity on the tobacco aphid, Myzus nicotianae Blackman. Synthetic sucrose esters provided moderate to good insecticidal activity against tobacco aphids in laboratory evaluations. Octanoyl sucrose esters were most toxic, and decanoyl sucrose esters were least toxic to aphids. Only the octanoyl sucrose esters at a 2 mg/ml rate were as toxic to aphids as the natural sugar esters from Nicotiana gossei Domin. They were also the most effective synthetic sucrose esters against aphids when a CO2 hand-held sprayer was used. All of the synthetic sucrose esters demonstrated significantly higher aphid mortality at a rate of 2 mg/ml than at 1 mg/ml. Heptanoyl and octanoyl sucrose esters provided significantly higher aphid control under wet conditions than under dry conditions in the laboratory. Results from field tests were inconsistent. Field evaluations conducted in 1995 showed that the four synthetic sucrose esters were moderately toxic at a rate of 4 mg/ml using a CO2 hand-held sprayer and low to moderately toxic using a high clearance sprayer. The addition of a surfactant (Volpo G-31, Silwet L-77 or Volpo G-31 plus Silwet L-77) significantly improved the efficacy of octanoyl sucrose esters when a CO2 hand-held sprayer was used. Relatively low aphid control was obtained with octanoyl sucrose esters in the field even though two surfactants were added when a high clearance sprayer was used at rates of 840 L/ha and 1400 L/ha.
Monitoring Pyrethroid Resistance in Bollworm (Lepidoptera: Noctuidae) Moths in Missouri, 1988 to 1994
Authors: Sorenson Clyde E. , Schreiber Alan , Townsend Howard G. , Abd-Elghafar Samir F. , Fairchild Mahlon L. , Knowles Charles O.
Published: September 2017

From 1988 to 1994, adult vial bioassays were conducted on bollworms, Helicoverpa zea (Boddie), collected from pheromone traps in Missouri to determine their susceptibility to pyrethroids. Although most moths were susceptible to cypermethrin, many assays contained individuals that survived concentrations of 5 and 10 μg per vial. The number of individuals that survived these concentrations increased each of the first 3 yrs, and then fluctuated from year to year. In some cases, moths with increased tolerance to cypermethrin occurred in locations where little or no pyrethroid insecticides were used for bollworm control. A likely explanation for tolerant bollworms in Missouri is immigration from more southerly locations, and evidence for long range dispersal of these insects is presented. Implications for regional resistance monitoring also are discussed.
Incidence of Arthropods Infested with Conidia of the Dogwood Anthracnose Fungus, Discula destructiva Redlin, on Flowering Dogwoods in the Natural Environment
Authors: Holt H. Lee , Grant Jerome F. , Windham Mark T.
Published: September 2017

Arthropods were collected from flowering dogwoods infected with Discula destructiva Redlin, causal agent of dogwood anthracnose, to evaluate their ability to transport viable conidia. During 1994, 7.2% of all arthropods collected (n = 375) from diseased trees at three sites in the Great Smoky Mountains National Park were carrying viable conidia of D. destructiva. Most [92.6% (25/27)] of the conidia-infested arthropods were collected during June when sporulation and spread of dogwood anthracnose were increasing. From July through September, the expansion of disease severity and incidence of sporulation diminished and the frequency of conidia-infested arthropods decreased. Several species of arthropods with viable conidia of D. destructiva were collected lending support to the hypothesis that insects and other arthropods may play a role in the spread of dogwood anthracnose.
Evaluation of a Water-Soluble Bait for Corn Rootworm (Coleoptera: Chrysomelidae) Control2
Authors: Schroder Robert F. W. , DeMilo Albert B. , Lee Chang-Joo , Martin Phyllis A. W.
Published: September 2017

Laboratory and field-cage experiments evaluated the efficacy of a water-soluble bait for control of adult diabroticites. The bait was composed of a water-soluble feeding stimulant derived from a bitter mutant of Hawkesbury watermelon (Citrullus vulgaris Schrad), a dye toxin (phloxine B: D & C Red Dye No. 28), and a modified food starch (Mira Sperse 626). In the laboratory, southern corn rootworm, Diabrotica undecimpunctata howardi Barber adults, were exposed to separate bait components and combinations thereof. Eighty percent of adults exposed to the complete bait formulation died within 24 h. Adult mortality increased with higher concentrations of dye and increasing light intensity. Incorporation of the feeding stimulant with the dye reduced the lethal time. The complete bait was most active in sunlight, killing 90% adults in 1 h. Under fluorescent lights, the LT90 for the adults was 48 h. In field cages, using corn plants treated with the bait formulation, numbers of live western corn rootworm, D. virgifera virgifera LeConte, adults were reduced by 80% compared with the untreated control. This new water soluble toxic bait appears suitable for testing on a larger scale in the field as a component of an IPM program for corn rootworm pests.
Relative Activity of Commercial Formulations of Bacillus thuringiensis Against Selected Noctuid Larvae (Lepidoptera: Noctuidae)
Authors: Luttrell R. G. , Ali Abbas , Young S. Y. , Knighten Kathy
Published: September 2017

Diet incorporation and spray chamber assays compared the activity of three commercial formulations of Bacillus thuringiensis Berliner against Heliothis virescens (F.), Helicoverpa zea (Boddie), Pseudoplusia includens (Walker), and Spodoptera exigua (Hübner). The commercial products evaluated were Condor OF® (Ecogen Inc., Langhorne, PA), Dipel ES® (Abbott Laboratories, North Chicago, IL), and Javelin WG® (Sandoz Crop Protection Corp., Des Plaines, IL). Variation in results of the diet incorporation studies illustrated the importance of including a standard reference formulation in the design of the studies and suggested that some standardization of insect strains used in such assays may be important also. Overall results of the diet incorporation studies were similar to those obtained in the spray chamber studies where insects were assayed on sprayed cotton and soybean. Dose-mortality regressions were developed for each B. thuringiensis formulation applied against each insect species on cotton and soybean over a 28-day observation period. These regressions may be helpful in the development of recommendations for the use of B. thuringiensis on cotton and soybean. They may also have value in establishing base-line levels of susceptibility for future resistance monitoring efforts. Median lethal concentrations (LC50s) tended to be slightly higher on cotton than on soybean. The most susceptible insect species was H. virescens, and the least susceptible was S. exigua. LC50s for H. zea and P. includens were similar and intermediate between those of H. virescens and S. exigua. Javelin WG tended to exhibit the highest activity per unit weight of commercial product, but the relative differences among the commercial formulations were influenced by insect species.
Evidence of Pheromone Catabolism Via β-Oxidation in the European Corn Borer (Lepidoptera: Crambidae)
Authors: Klun Jerome A. , Khrimian Ashot P. , Oliver James E.
Published: September 2017

Experiments were conducted using tritiated European corn borer, Ostrinia nubilalis (Hübner), pheromone, (Z)-[11,12-3H2]-11-tetradecen-1-ol acetate, a tritiated fluorinated analog of the European corn borer pheromone, 2-fluoro-(Z)-[11,12-3H2]-11-tetradecen-1-ol acetate, and methyl-4-bromocrotonate (MBC) to determine if pheromone catabolism proceeds on the moth's antennae via the β-oxidation pathway of fatty acid degradation. When antennae were treated with tritiated natural pheromone plus MBC (a precursor of the known β-oxidation inhibitor, 4-bromocrotonic acid), catabolism of the pheromone was significantly inhibited. When the 2-fluoro pheromone analog was applied alone to antennae, it was hydrolyzed to the corresponding alcohol but was not degraded. MBC had no effect on catabolism of the 2-fluoro analog, and 2-fluoro substitution inhibited entrance of the compound into β-oxidation. These results demonstrate that β-oxidation is the primary oxidative pathway by which pheromone is degraded on the antennae of European corn borer moths.
Parasitism of Diamondback Moth (Lepidoptera: Plutellidae) Larvae by Cotesia plutellae (Hymenoptera: Braconidae) and Diadegma insulare (Hymenoptera: Ichneumonidae) in Cabbage Fields after Inundative Releases of C. plutellae2
Authors: Mitchell E. R. , Hu G. Y. , Okine J. S. , Carpenter J. E.
Published: September 2017

Cocoons of Cotesia plutellae (Kurdjumov) were released for nine consecutive wk along the margins of two commercial cabbage (Brassica oleracea var. bravo L.) fields near Bunnell, Flagler Co., FL, in spring 1996. The larval parasitism of diamondback moth, Plutella xylostella (L.), by C. plutellae and by the native parasitoid Diadegma insulare (Cresson) was evaluated in release fields and in nearby cabbage fields using two methods-sentinel collard (Brassica oleracea var. acephala L.) or sentinel cabbage plants and non-sentinel plants. Total parasitism of diamondback moth larvae on sentinel plants in the release and adjacent fields was 35.7%. There were no significant differences in the level of parasitism by C. plutellae among sentinel plant locations within the release fields. In non-release fields, parasitoids spread as far as 1,500 m from the nearest release site during the release period, but parasitism of larvae on sentinel plants decreased as the distance from the release area increased. Parasitism of diamondback moth larvae by D. insulare was 8.3% in C. plutellae release and adjacent fields, but 14.6% in the nearby fields. Sampling of non-sentinel cabbage plants for diamondback moth larvae demonstrated a total of 37.4% larval parasitism by C. plutellae in the release and adjacent fields, similar to that recorded on sentinel plants. However, C. plutellae were detected only as far as 800 m from the release site on non-sentinel cabbage plants, and total parasitism in the dispersal fields also was very low. Diadegma insulare contributed only 1.1% parasitism of larvae sampled from non-sentinel plants in all cabbage fields. Cotesia plutellae was more effective than D. insulare in attacking diamondback moth larvae in this study where field populations of diamondback moth were low (<0.1 larva per cabbage plant).
Laboratory Screening Techniques for Evaluation of Soybean Germplasm for Resistance to Twospotted Spider Mite (Acari: Tetranychidae)
Authors: Elden T. C.
Published: September 2017

Thirty-one soybean, Glycine max (L.) Merrill, accessions from maturity groups II through VIII were evaluated in excised and intact (whole plant) leaf bioassays to determine the ability of these bioassays to detect differences in susceptibility to the twospotted spider mite, Tetranychus urticae Koch. Although there were few significant differences between bioassays for variables measured within maturity groupings, the excised leaf bioassay which was easier to set up and monitor and took three-fourths less growth chamber space also had less variation among replications and repeated tests and detected a greater number of differences among accessions. Although there were significant differences among soybean accessions within a maturity group for specific variables, results suggest that high levels of resistance to the twospotted spider mite are not present in the germplasm screened. Several accessions screened, with known resistance to foliar feeding insects, were significantly less preferred for spider mite oviposition and development. However, it was apparent that the gene(s) controlling insect resistance do not impart the same level of resistance to the twospotted spider mite. Results of this study, based on differences in susceptibility among soybean accessions, demonstrate that the excised leaf bioassay should prove to be an efficient and uniform laboratory bioassay to screen soybean germplasm for resistance to the twospotted spider mite.
Interactions in Entomology: Mid-Season Dimilin and Boron Treatment Impact on the Incidence of Arthropod Pests and Yield Enhancement of Soybeans
Authors: McPherson R. M. , Gascho G. J.
Published: September 2017

Twelve replicated soybean field trials were conducted in 1993–1997 to evaluate the effects of a foliar application of the insect growth regulator Dimilin® (0.07 or 0.035 kg Al/ha) and the plant nutrient boron (0.28 kg nutrient/ha) on the incidence of insect pests and the enhancement of yield and quality. Dimilin (diflurbenzuron) was very effective at all test locations in controlling velvetbean caterpillars, Anticarsia gemmatalis Hübner, for the remainder of the season once the foliar application was made on soybeans in the R2 (full bloom) to R5 (pods filling with seeds) growth stage. Six of the test sites had significant yield increases in the Dimilin plots due to protection from economic crop injury from this pest. Dimilin was not effective in controlling stink bugs, primarily Nezara viridula (L.) and Euschistus servus (Say), and Mexican bean beetles, Epilachna varivestis Mulsant. Scout® (tralomethrin) and MVP® (Bacillus thuringiensis Berliner) did not provide adequate residual pest control when combined with the boron treatment. Yield enhancements from boron (Solubor®, soluble disodium octaborate tetrahydrate) were observed in seven tests, but yields were significantly higher than the no boron treatments in only three experiments. The nutrient applications did not influence the abundance of arthropod pests at any test location. The overall soybean yield enhancement of around 440 kg/ha (6.5 bu/a) above the untreated plots represents a positive net economic return for the total investment of around $55 per ha. Dimilin accounted for most of the yield increase due to effective pest control, but the addition of boron costs very little ($3.00/ha) with a return of about 35 kg/ha across all soil types (higher response in sandy soils). It appears that a dimilin/boron foliar application around R3 stage soybeans (small pods forming) can be a profitable strategy in south Georgia, especially in areas where velvetbean caterpillars are annual economic pests and the fields contain sandy soil with low levels of available boron.
Interactions in Entomology: Multiple Comparisons and Statistical Interactions in Entomological Experimentation
Authors: Bondari K.
Published: September 2017

Research reports published in agricultural journals indicate that in many situations the use of multiple comparison procedures has been either inappropriate or not the most meaningful method of analyzing the data. When the interaction is absent, only main effects should be reported in scientific journals, with some assurance that the effect of one factor holds at all levels of the other factor. However, when interaction is present, more detailed analyses and sometimes plotting the means for each of the cells may be very helpful in understanding the results. Multiple comparisons, main effects, and interactions are discussed using entomological examples to present a more meaningful and understandable explanation of statistical techniques to those researchers who conduct experiments in which each level of one factor occurs in combination with each level of another factor. Analysis of variance, contrasts, and fixed and random effects are also discussed.
Interactions in Entomology: Enhanced Infectivity of Entomopathogenic Viruses by Fluorescent Brighteners
Authors: Hamm John J.
Published: September 2017

Fluorescent brighteners or optical brighteners, chemicals that absorb energy from ultraviolet light (UV) and emit it as visible light, have been studied as UV protectants for entomopathogens to extend their effectiveness in the field as biocontrol agents. Some stilbene fluorescent brighteners have been demonstrated both to provide some protection from UV degradation and to enhance infectivity independently of the UV protection for several entomopathogenic viruses. Although the mode of action of this enhanced infectivity is not fully understood, enhanced infectivity of 10 nucleopolyhedroviruses and a granulovirus (Baculoviridae), a cypovirus (Reoviridae), an iridovirus (Iridoviridae), and an entomopoxvirus (Poxviridae) has been demonstrated. The enhanced infectivity produced by the fluorescent brighteners generally resulted in earlier mortality and in some cases extended infectivity of the virus to older instars. In a few cases the host range was extended, i.e., viruses which were not infective for a particular species under normal conditions were infective with the addition of a fluorescent brightener. Thus, if proper formulations can be made, the fluorescent brighteners have the potential to increase the effectiveness of certain entomopathogenic viruses for biocontrol of certain lepidopterous pests of forest and agricultural crops.
Influence of Weather and Time of Day on Plum Curculio (Coleoptera: Curculionidae) Tree Canopy Entry Behaviors and Evaluation of Traps for Predicting Fruit Injury
Authors: Dixon Bonnie M. , Prokopy Ronald J. , Schultz Brian B.
Published: September 2017

In the spring of 1997, tree canopy entry behaviors of adult plum curculios, Conotrachelus nenuphar (Herbst), were estimated by three types of traps examined five times each day from 24 May (bloom) until 15 June in an unmanaged apple orchard. In addition, presence of plum curculios in the canopy, ovipositional injury to fruit, and local weather conditions (temperature, barometric pressure, relative humidity, and wind speed) were monitored. The principal means of entry into apple trees by plum curculios appeared to be direct flights from outside the canopy into the canopy. However, the major means of tree entry on days when large amounts of oviposition occurred appeared to be crawling up or flying onto the trunk. Ovipositional injury to fruit was correlated with high temperature and low barometric pressure. The greatest amount of tree entry occurred between 1800 and 2100h. The strongest correlation found between daily trap captures and daily occurrence of injury was between captures by flight interception traps placed just outside the canopy and injury occurring the following day. Based on this, captures by flight interception traps just outside the canopies of fruit trees may have potential for predicting episodes of plum curculio damage to fruit.
Archytas marmoratus (Diptera: Tachinidae) Survival in Diapausing and Nondiapausing Strains of Helicoverpa zea (Lepidoptera: Noctuidae)
Authors: Proshold F. I. , Carpenter J. E.
Published: September 2017

Archytas marmoratus (Townsend) was reared on four strains of corn earworm, Helicoverpa zea (Boddie). One strain did not diapause or entered a weak diapause. A portion of the other three strains entered diapause when reared at 19 or 22°C and 10:14 h photoperiod (L:D). No A. marmoratus entered diapause; 90% eclosed with no differences among strains or rearing condition, and the number of days from host pupation to eclosion within rearing condition was similar regardless of host strain. Parasitized pupae did not enter a chill-terminated diapause, as indicated by loss of larval eyespots within 2 wks. Either the presence of A. marmoratus maggots prevented diapause in its host or diapause was terminated by rapid development of the maggot after host pupation. These data suggest that A. marmoratus does not overwinter as a larva or pupa in the cooler regions of its distribution.
Patterns of Honeydew Droplet Production by Nymphal Stages of Bemisia argentifolii (Homoptera: Aleyrodidae) and Relative Composition of Honeydew Sugars
Authors: Costa H. S. , Toscano N. C. , Hendrix D. L. , Henneberry T. J.
Published: September 2017

Honeydew droplets were collected from nymphal and adult Bemisia argentifolii Bellows and Perring. Nymphs produced a regular pattern of honeydew droplets consisting of periods of production followed by periods where no droplets were produced. The mean length of individual production periods increased from the second (40 ± 1 min) to the fourth (162 ±11 min) stadium, until the late fourth stadium when honeydew production by most nymphs became continuous. In contrast, the periods of no production decreased in length as nymphs developed from the second (35 ± 1 min) to the fourth (23 ± 1 min) stadium. The frequency of droplets during the production periods decreased from the first (80 ± 1 drops per h) to the fourth (22 ± 1 drops per h) stadium. This periodic pattern is consistent with previous reports for Trialeurodes vaporariorum (Westwood), however, the functional significance of this pattern remains unknown. If this cyclic pattern should prove critical to the successful feeding and development of whiteflies, its disruption may decrease survival and provide a novel target for pest control strategies. Second and third instars had higher percentages of di- and trisaccharides (sucrose, trehalulose, and melezitose) and lower percentages of monosaccharides (fructose and glucose) compared to first and fourth instars. This could indicate a change in metabolic needs of nymphs during periods of rapid growth, or indicate that trehalulose synthase producing endosymbiotic bacteria are more abundant, or more actively producing enzyme during the second and third stadia.
Spider Prey of Two Mud Dauber Wasps (Hymenoptera: Sphecidae) Nesting in Georgia's Okefenokee Swamp
Authors: Volkova Tatiana , Matthews Robert W. , Barber M. Craig
Published: September 2017

Spiders captured by Trypoxylon politum (Say) and Sceliphron caementarium (Drury) in Georgia's Okefenokee Swamp over two nesting seasons represented 5 families and 22 genera (n = 5191). A strong bias for female spiders exists in both species (89.5% of all prey), with immature females comprising nearly half of these (42.6%). Comparison of contemporaneously taken prey at the same site by T. politum using typical mud organ pipe nests or trap nests revealed that the same araneid species of Neoscona and Eustala predominated. However, spiders provisioned in trap nests were more diverse taxonomically, including the first records of Mimetidae and Salticidae as prey for this wasp, as well as a variety of other araneid genera. Seasonal changes in prey composition revealed no particular patterns or correlations with nest type. Sceliphron caementarium displayed a strong preference for araneid spiders, with N. arabesca comprising 53.8% of the total; Thomisidae comprised 10.5%, nearly all Misumenops oblongus.
Current Distribution and Historical Range Expansion of Calosoma sycophanta (L.) (Coleoptera: Carabidae) in North America
Authors: Schaefer Paul W. , Fuester RogerW. , Taylor Philip B. , Barth Susan E. , Simons Edward E. , Blumenthal E. Michael , Handley Elizabeth M. , Finn Thomas B. , Elliott Ernest W.
Published: September 2017

Since the intentional introduction, release, and establishment of the lymantriid predator, Calosoma sycophanta (L.), in 1906–07 in the vicinity of Boston, MA, its range has continued to expand. Compilation of collection localities, all intentional releases in North America, and museum collection records permitted documentation of spread over time and a crude straight line estimate of the rate of dispersion, calculated at 6 km/year. Trapping and other collection records in recent years permitted an approximation of the current distribution, which now extends from southern Maine and all New England states south into Pennsylvania, Delaware, Maryland, and West Virginia. During 15 years of trapping at one New Jersey site and in the mid-Atlantic states, we collectively placed 3,792 traps in 253 locations. We captured 12,117 C. sycophanta, most of which were immediately released on location. Of those that were sexed (4,160), 74.3% were males. We recorded new state records for Delaware, Maryland, and West Virginia. Other species trapped include C. scrutator (200 specimens, most in New Jersey), C. wilcoxi (12, most in Delaware), C. frigidum (896, most in Pennsylvania) and C. calidum (22, most in Virginia).
Efficacy of Gypchek Against the Gypsy Moth (Lepidoptera: Lymantriidae) and Residual Effects in the Year Following Treatment
Authors: Webb R. E. , Thorpe K. W. , Podgwaite J. D. , Reardon R. C. , White G. B. , Talley S. E.
Published: September 2017

Gypsy moth, Lymantria dispar (L.), populations in three Maryland plots and three West Virginia plots were treated aerially with the gypsy moth multienveloped nuclear polyhedrosis virus product, Gypchek® (U.S. Forest Service, USDA, Washington, DC). The study was a pilot test to demonstrate the efficacy of a single application of Gypchek suspended in the commercially-produced Carrier 038® (Abbott Laboratories, N. Chicago, IL) at 9.5 liters and 1 × 1012 polyhedral inclusion bodies per ha. This treatment resulted in virus levels that were significantly higher in the treated woodlots (58.7%) than in paired control woodlots (10.5%), with treatment effects highly significant. Results from treated plots in West Virginia (67.7% posttreatment virus infection) were clearly superior to results from Maryland (49.7% post-treatment virus infection) probably due to more favorable conditions during application in West Virginia. Defoliation averaged 15% in the treated woodlots and 32% in the control woodlots; however, a high degree of variability in the control woodlots, perhaps due to compensatory mortality, probably caused by a late-season epizootic of the fungus Entomophaga maimaiga Humber, Shimazu & Soper, accounted for the treatment effects being statistically non-significant at P = 0.05. Significantly higher levels of virus were found in treated woodlots than in control woodlots in an early-season larval collection made the year following treatment (1997) with virus levels averaging 11.7% in treated plots vs 5.0% in control plots. The second-year effects were particularly striking in the West Virginia plots (12.7% in treated plots vs 3.0% in control plots) suggesting that Gypchek applications may be particularly desirable in situations where natural virus is low or absent. The results of the pilot test now give forest managers the option of using one application (full dose) or two applications (split dose) of Gypchek against the gypsy moth.
Tobacco Budworm, Heliothis virescens (Lepidoptera: Noctuidae): Larval Location and Mortality on Bacillus thuringiensis-Treated Cotton
Authors: Jyoti J. L. , Young S. Y. , Johnson D. T. , McNew R. W.
Published: September 2017

One-d-old Heliothis virescens (F.) larvae were placed on Bacillus thuringiensis var. kurstaki Berliner-treated cotton leaves and terminals in the laboratory. Larval movement, food consumption and mortality were examined at 3, 6, 12, 24 and 48 h. Untreated leaves had a greater percentage of larvae on their under side than on their upper side; this location was not influenced by treatment with B. thuringiensis. When B. thuringiensis was applied to cotton terminals, first instars moved from B. thuringiensis-treated meristems; this movement increased with an increase in rate. Bacillus thuringiensis treatment also resulted in increased movement of larvae from the leaves and terminals onto the inner cup surface, although this movement was significantly greater than the untreated control only during the first 12 h after treatment. The leaf area consumed decreased with an increase in B. thuringiensis rate, but was not significantly correlated with larval mortality.
Ovipositional Stimuli of Angoumois Grain Moth (Lepidoptera: Gelechiidae), a Primary Pest of Stored Grains
Authors: Weston Paul A. , Rattlingourd Patti L.
Published: September 2017

Ovipositional preferences of Sitotroga cerealella (Olivier) were measured in the laboratory to characterize the stimuli eliciting oviposition in this widespread pest of stored grains. Substrates used for oviposition included grains presenting both physical and chemical stimuli as well as surrogates presenting only physical stimuli. Chemical factors associated with grains stimulated oviposition, but physical stimuli, primarily the presence of crevices, were of much greater importance. Moths reared for approximately 15 generations in the laboratory were less sensitive to grain factors than were moths more recently collected from the field. Experiments with surrogrates presenting a precisely defined range of crevice sizes confirmed that ovipositional response increased as crevice size narrowed. The results suggest that factors influencing habitat selection are probably very important in this insect because of indiscriminate oviposition on substrates that present appropriate physical stimuli but are entirely unsuitable for larval consumption.
Evaluation of Foliar-Applied Insecticides on Abundance of Parasitoids of Bemisia argentifolii (Homoptera: Aleyrodidae) in Vegetables2
Authors: Simmons Alvin M. , Jackson D. Michael
Published: September 2017

The relative abundance of parasitoids of Bemisia argentifolii Bellows & Perring was studied in insecticide-treated and untreated field plots of cantaloupe, collard, cucumber, and tomato. Treatments were made using foliar-applied chlorpyrifos (Lorsban®, DowElanco, Indianapolis, IN) in 1994, and foliar-applied imidacloprid (Provado®, Bayer Corporation, Kansas City, MO) in 1995 and 1996. Yellow sticky cards were used to monitor parasitoids associated with B. argentifolii in plots untreated or treated weekly in 1994 and bi-weekly in 1995 and 1996 with insecticide over 10 wks. The abundance of parasitoids varied among fields and across years. Five species of parasitoids were captured: Eretmocerus sp., Encarsia nigricephala Dozier, E. pergandiella Howard, E. quaintancei Howard, and E. strenua (Silvestri). The first three species comprised approximately 95% of the captured parasitoids. Parasitoids persisted in all field locations and crops whether the vegetables were treated or not. Parasitoids were captured in the treated plots throughout the study, although in fewer numbers than in the untreated plots. Overall, about 60 to 70% of parasitoids captured were from plots without insecticide. Whitefly captures on the sticky traps were relatively high in collard compared with the other crops studied. In addition, more E. nigricephala and E. pergandiella were collected in collard than in the other vegetable crops.
Bemisia argentifolii Adult, Nymph and Egg Densities and Egg Distribution on Selected Upland Cottons
Authors: Chu C. C. , Freeman T. , Natwick E. T. , Buckner J. S. , Nelson D. R. , Henneberry T. J.
Published: September 2017

Five upland cotton, Gossypium hirsutum L., cultivars, Deltapine (DPL) 50, 5415 and 5432, Fibermax 832 and Siokra L23, were studied in relation to silverleaf whitefly, Bemisia argentifolii Bellows and Perring, oviposition and colonization. Deltapine 5415 and 5432 had the highest numbers of eggs and nymphs and Siokra L-23 the lowest. Siokra L-23 also had the lowest number of adults compared to the other four cultivars. Over 75% of eggs were oviposited on leaf surfaces between veins and 23% were oviposited in veins that were ≤4 cells wide. Few eggs were found on veins that were five or more cells wide. No eggs were inserted into leaf stomata.