bluuebunny/crossref_metadata_2025 huggingface dataset:
Overwintering Biology, Food Supplementation and Parasitism of Eggs of Homalodisca Coagulata (Say) (Homoptera: Cicadellidae) by Gonatocerus Ashmeadi Girault and Gonatocerus Morrilli (Howard) (Hymenoptera: Mymaridae)
Authors: López Rolando , Mizell Russell F. , Andersen Peter C. , Brodbeck Brent V.
Published: September 2017

The efficiency of parasitism of Gonatocerus ashmeadi Girault and G. morrilli (Howard) (Hymenoptera: Myramidae) on glassy-winged sharpshooter, Homalodisca coagulata (Say) (Homoptera: Cicadellidae), eggs of varying age was documented. Excised leaves with H. coagulata eggs of age 1 to 9 d were presented to mated female parasitoids in Petri dishes as well as on intact foliage. Parasitism rates for both species were high with 3 females in Petri dishes parasitizing virtually all eggs in 3 egg masses, and 8 mated females finding and parasitizing almost all eggs from 5 egg masses in small shrubs of Ilex opaca cv cornuta. For both species, parasitism efficiency exceeded 95% within 24 h. Parasitism rates declined for older eggs (8 and 9 d) on excised leaves. Because this did not occur on live plant material, hardening of excised foliage likely contributed to lower rates of parasitism. No cases of superparasitism were observed: Overwintering of the parasitoids was examined by monitoring the fate of eggs of H. coagulata deposited in November. We documented the first case of H. coagulata overwintering as eggs under North Florida conditions. In addition, both G. ashmeadi and G. morrilli were able to overwinter as undeveloped larvae within parasitized eggs under similar conditions. Overwintering parasitoids took approximately 85 d for emergence, which slightly exceeded the minimum predicted for emergence by existing degree day models. Feeding experiments conducted with G. ashmeadi and G. morrilli as food sources are limited during winter/spring; however, our results confirmed that honeydew from Dialeurodes citri (Ashmead) (available in North Florida in late winter/early spring) significantly increased the longevity of both parasitoid species when compared to honey and water.
Characterization of Soybean Looper (Lepidoptera: Noctuidae) Tolerance to Bollgard® Cotton: Implications for Resistance Management
Authors: Gore Jeffrey , Adamczyk John J.
Published: September 2017

The soybean looper, Pseudoplusia includens (Walker), is an occasional pest of cotton and an annual pest of soybean in the southern United States. The development of resistance by soybean looper to the Bacillus thuringiensis Berliner Cry1Ac protein in Bollgard® cotton could potentially influence the efficacy of foliar B. thuringiensis products in soybean. Soybean looper larvae and pupae collected from plots of Bollgard cotton weighed less than larvae and pupae collected from non-Bollgard cotton. Soybean loopers collected from non-Bollgard and Bollgard cotton were maintained separately in the laboratory. No differences were observed in the susceptibility of the subsequent generation (F1) of soybean looper larvae from non-Bollgard and Bollgard cottons to Cry1Ac based on concentration-mortality data. Neonates from each of these colonies were allowed to complete development on non-treated and Cry1Ac-treated (1.0 μg/ml) meridic diet. Larval weights at 9 d and pupal weights were lower on Cry1Ac-treated diet than on non-treated diet. There were no apparent vigor differences in the two colonies based on development on non-treated diet. In addition, developmental times of larvae from both colonies were longer on Cry1Ac diet than on non-treated diet. These data indicate that development of soybean looper on Bollgard cotton has no effect on the tolerance of subsequent soybean looper generations to Cry1Ac.
Host Plant Influence on Activity of Bacillus thuringiensisBerliner Against Lepidopterous Pests of Crops
Authors: Ali M. Ibrahim , Young S. Y. , McNew R. C.
Published: September 2017

Mortality of second-instar Helicoverpa zea (Boddie), Spodoptera exigua (Hübner) and Pseudoplusia includens (Walker) fed Bacillus thuringiensis Berliner (Bt), Dipel ES®-sprayed leaves of field grown cotton, soybean and tomato were compared in laboratory bioassays. The median lethal concentration (LC50) for larvae of all species fed Bt-treated leaf tissue was higher for cotton than for soybean or tomato. The LC50 for larvae fed Bt-treated soybean and tomato leaves did not differ significantly for any species of insects. When the mean number of days until death was plotted against percent survival at that rate, the mean number of days until death increased with an increase in percent survival. Survival time of the three insect species exposed to Bt increased most rapidly when fed cotton leaves. Results show that foliarly-applied Bt on field-grown cotton leaves is less effective against larvae of these pest species in terms of mortality and speed of kill.
Trunk Perimeter Applications of Beauveria bassiana to Suppress Adult Curculio caryae (Coleoptera: Curculionidae)1
Authors: Shapiro-llan David I. , Cottrell Ted E. , Gardner Wayne A.
Published: September 2017

The pecan weevil, Curculio caryae (Horn), is a key pest of pecans. Entomopathogenic fungi, such as Beauveria bassiana (Balsamo) Vuillemin, can infect this pest. Our objectives were to determine the potential of B. bassiana, to suppress emerging C. caryae adults when applied to soil around pecan tree-trunks, and to determine persistence of B. bassiana in the soil. In 2000 and 2001, B. bassiana was applied to soil in a 2 m band around pecan tree trunks. Naturally emerging C. caryae adults, caught after they crawled to the trunk, were brought to the laboratory to determine percentage mycosis. In Byron, GA, irrigation was applied to one-half of the plots, whereas, in Griffin, GA irrigation was not applied. In Byron, in both years, we observed greater fungus-induced mortality in plots that received B. bassiana without irrigation than in plots that received B. bassiana with irrigation or in the checks (with and without irrigation). In Griffin, in the year 2000, we observed higher C. caryae mortality in B. bassiana treated plots than in non-treated plots, whereas 2001 results showed no difference. Although we observed up to 95% B. bassiana-induced mortality within the first 3 d post-application, treatment effects did not persist beyond the first week post-application. Future research should focus on extending the persistence of B. bassiana suppression. Estimates of conidia production per B. bassiana infected insect yielded up to 4.2 × 109 suggesting some recycling might occur in the soil.
Microctonus melanopus (Ruthe) (Hymenoptera: Braconidae), a Parasitoid of Adult Cabbage Seedpod Weevil (Coleoptera: Curculionidae): Distribution in Southern Alberta and Female Diagnosis
Authors: Fox Andrew S. , Shaw Scott R. , Dosdall Lloyd M. , Lee Byron
Published: September 2017

Microctonus melanopus (Ruthe) were reared and dissected from adult cabbage seedpod weevil, Ceutorhynchus obstrictus (Marsham), collected in southern Alberta in 2000 and 2001, and M. melanopus females were collected near Creston, British Columbia in 2001. These collections represent the first records for this European species in Canada. Previously published records of M. melanopus in North America are from the northwestern United States. A first diagnosis for adult female M. melanopus is provided that places M. melanopus in Loan's (1969) key for Microctonus species of North America, north of Mexico. Scanning electron photomicrographs of female morphology are provided to illustrate important diagnostic characters: the mesonotal sculpture with a distinct median longitudinal carina posteriorly, and the sculpture of metasomal tergite 1 with costae distinctly converging posteriorly. It is probable that M. melanopus has long been established in the southern interior of British Columbia because its host, C. obstrictus, has occurred there for many years. The occurrence of M. melanopus in southern Alberta is likely more recent, as its host only recently dispersed to that region. Rates of parasitism of C. obstrictus by M. melanopus, with one exception, were low in southern Alberta (<10%), and only one parasitized weevil was found on spring-seeded Brassica napus L., the primary brassicaceous oilseed crop associated with the weevil on the Canadian prairies. We hypothesize that M. melanopus will not provide substantial control of C. obstrictus in the mixed grassland ecoregion of its new range.
Effects of Elevated Carbon Dioxide Levels and Temperature on the Life History of the Madeira Mealybug (Hemiptera: Pseudococcidae)
Authors: Chong Juang-Horng , van lersel Marc W. , Oetting Ronald D.
Published: September 2017

Atmospheric carbon dioxide concentrations and temperatures are increasing and, thus, the interactions between insect herbivores and their host plants in environments of elevated CO2 concentration and temperature must be examined. We investigated the combined effects of elevated atmospheric CO2 concentration (400 and 700 μmol mol−1) and temperature (20, 25 and 30°C) on the development, survival and reproduction of two generations of the Madeira mealybug, Phenacoccus madeirensis Green, and the chemical composition of chrysanthemum, Dendranthema × grandiflora Kitam., leaves. The development of the mealybugs was temperature-driven and was not influenced by the CO2 level or the number of generations. At higher temperatures, the duration to egg eclosion and the developmental time of adult females and males were significantly shortened. More eggs survived to adulthood at higher temperatures. Temperature had no influence on the egg eclosion percentage. The reproductive period of females was shortest at 30°C, while fecundity was highest at 20°C. There was a significantly higher proportion of females at the end of the experiment at lower than at higher temperatures. Elevated CO2 level and temperature did not change the chemical composition (nitrogen and carbon concentrations, and carbon-nitrogen ratio) of the host plants. Relative water content of the leaf tissues was higher at 30°C than other temperature treatments. Our results show that the effects of temperature on the biology of the Madeira mealybug were stronger than that of the elevated CO2 concentration.
Persistence of Diflubenzuron on Soybean Leaves
Authors: Southwick Lloyd M. , Willrich Melissa M. , Fouss James L. , Boethel David J.
Published: September 2017

Diflubenzuron [Dimilin™, N-[{(4-chlorophenyl)amino}carbonyl]-2-6-difluorobenzamide] is an insect growth regulator that is highly effective and provides residual control (up to 54 days) against velvetbean caterpillar, Anticarsia gemmatalis Hübner, on soybean, Glycine max (L.) Merrill, in Louisiana. We conducted a study to quantify the field persistence of diflubenzuron residues on soybean leaves when applied at 0.035 kg/ha, a rate used in preventive programs for velvetbean caterpillar. Day of application (day 0) concentration of the insecticide on the leaves was 206 ± 41 ng/cm2. By 14 days after treatment insecticide leaf coverage had decreased to about 20 ng/cm2, where it remained for the remainder of the study. This persistent low level residue on the soybean leaves is consistent with the extended diflubenzuron efficacy toward velvetbean caterpillar that has been documented in Louisiana.
Wing Formation and Reproduction from Insecticide-Treated Cotton Aphids (Homoptera: Aphididae)
Authors: Conway Hugh E. , Kring Timothy J.
Published: September 2017

Field observations of the cotton aphid, Aphis gossypii Glover, from 1999 to 2001 indicated an increase in percentage of winged aphids in cotton fields after an application of imidacloprid. Cotton aphid wing formation and fecundity of offspring were evaluated in a spray booth following five treatments: imidacloprid near LC50 concentration on cotton, dicrotophos near LC50 concentration on cotton, water spray on cotton, water spray on silk plants, imidacloprid spray near LC50 concentration on silk plants. Silk plants were used to differentiate topical and systemic effects of imidacloprid. Prior to spraying, 40 aphids were transferred onto each plant. Aphids were moved from the silk plants onto unsprayed cotton plants 3 h post-spray. Offspring from imidacloprid-treated aphids on cotton produced twice as many winged offspring (8%) as did aphids from other treatments (3% to 4%) and only one-third as many offspring per founding relative to aphids in other treatments. In addition to increasing emigration by winged aphids, an increase in the proportion of winged aphids among survivors of an imidacloprid treatment may further reduce the number of aphids in a treated field because winged aphids require a longer developmental time, produced fewer offspring, and have an increased risk of mortality.
Temporal Foraging Activity of Selected Ant Species in Northern Mississippi During Summer Months1
Authors: Vogt James T. , Reed Jack T. , Brown Richard L.
Published: September 2017

A study was conducted in northeastern Mississippi to examine temporal foraging activity of imported fire ants (Solenopsis spp.) and other common ant species that inhabit pasture and meadow. Baited vials were placed horizontally on the ground along straight-line transects (n = 21) every 3 h for 24 h periods during June–August. Vials remained on the ground for 30 min, then were quickly plugged with cotton and collected. Principal species captured in baited vials included Solenopsis spp. (black and hybrid imported fire ant) (90.6%), Solenopsis molesta (Say) (5.9%), Monomorium minumum (Buckley) (2.5%), Tapinoma sessile (Say) (0.7%), and Paratrechina vividula (Nylander) (0.3%). Imported fire ants foraged during all time periods, as did S. molesta and P. vividula. Tapinoma sessile and M. minimum slowed or ceased foraging at night. Forelius pruinosus (Roger) was captured on a single date while sampling at 1800 h. Implications for timing of bait applications against imported fire ants are discussed.
Conditions for Short-Term Storage of Field-Collected Spined Soldier Bug, Podisus maculiventris (Say) (Heteroptera: Pentatomidae), Adults Prior to Augmentative Release1
Authors: Thorpe Kevin W. , Aldrich Jeffrey R.
Published: September 2017

The date at which spined soldier bugs, Podisus maculiventris (Say) (Heteroptera: Pentatomidae), can be trapped for augmentative release against overwintered Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), may be up to 5 wks earlier than the date of peak Colorado potato beetle emergence, necessitating storage of field-collected spined soldier bugs prior to release. The effects of temperature, photoperiod, and food on spined soldier bug survivorship and fecundity during and after a 5-wk storage period were investigated. In general, unfed spined soldier bugs had greater mortality and reduced fecundity compared with those fed string beans and mealworm larvae during storage. Temperature and photoperiod generally had no effect. However, female spined soldier bug survivorship was greater among unfed insects stored at 5°C compared with those stored at 15°C. Therefore, household refrigerators can be used for short-term storage of field-collected spined soldier bugs. Even when stored spined soldier bug females are fed, fecundity is low (14 nymphs per female originally collected). This may limit the use of field-collected spined soldier bugs for augmentative release against Colorado potato beetle to relatively small plantings of potatoes.
Field Response of Dendroctonus valens (Coleoptera: Scolytidae) and a Major Predator, Temnochila chlorodia (Coleoptera: Trogositidae), to Host Kairomones and a Dendroctonus spp. Pheromone Component1
Authors: Fettig Christopher J. , Borys Robert R. , Cluck Daniel R. , Smith Sheri L.
Published: September 2017

The red turpentine beetle, Dendroctonus valens (LeConte) (Coleoptera: Scolytidae), is a common bark beetle species found throughout much of North America. Aggregation pheromones have yet to be isolated and identified for D. valens. In this study, we examined the response of D. valens and a bark beetle predator, Temnochila chlorodia (Mannerheim) (Coleoptera: Trogositidae), to host produced kairomones and to the Dendroctonus spp. pheromone component exo-brevicomin. A total of 11,604 D. valens and 586 T. chlorodia were captured in multiple-funnel traps over a 14-wk period from 27 March to 5 July 2002. There was no significant difference in trap catch related to gender. The ratio of males to females was 1.01 for D. valens and 0.97 for T. chlorodia. Dendroctonus valens showed significant attraction to (+)-α-pinene, (−)-β-pinene, and (+)-3-carene, but the addition of ethanol did not significantly increase trap catch. Racemic exo-brevicomin was not attractive to D. valens and significantly reduced its attraction to the monoterpene and ethanol blend. This observation, in combination with results from other authors, suggests that D. valens is not responding to the western pine beetle, D. brevicomis LeConte, pheromone or any of the individual components. Potential explanations for why D. valens is attracted to D. brevicomis infested trees are provided. There were no significant differences in the trap catch of T. chlorodia among unbaited traps or traps baited with (+)-α-pinene, (−)-β-pinene, and (+)-3-carene or (+)-α-pinene, (−)-(β-pinene, and (+)-3-carene, and ethanol. The addition of exo-brevicomin significantly increased attraction. During the course of this study, a single peak in flight activity was observed during late May through early June for both species.
Synergistic Chemical Attraction of the Eastern Yellowjacket, Vespula maculifrons (Hymenoptera: Vespidae)
Authors: Aldrich Jeffrey R. , Zhang Qing-He , Zhang Aijun
Published: September 2017

Combinations of (E)-2-hexenal diethyl acetal, racemic α-terpineol or linalool, with or without benzyl alcohol incorporated into polyvinyl chloride attracted wasps in the Vespula vulgaris species group, including the Eastern, Vespula maculifrons (Buysson), and German, V. germanica (F.), yellowjackets. (E)-2-Hexenal diethyl acetal degrades to release (E)-2-hexenal (the active attractant form) and ethanol, which may help kill yellowjackets caught in the water inside the traps used for testing. Combining the (E)-2-hexenal diethyl acetal/α-terpineol or linalool mixtures with another blend previously reported as attractive to yellowjackets (acetic acid/isobutanol) synergistically attracted the Eastern yellowjacket. It is hypothesized that the synergistic attraction is a result of combining volatile chemicals associated with carbohydrate feeding (acetic acid/isobutanol) and volatiles associated with foraging for insect prey (hexenal/α-terpineol or linalool).
Effects of Irradiation on Reproduction in Tarnished Plant Bug (Heteroptera: Miridae) and F1 Progeny
Authors: Villavaso Eric J.
Published: September 2017

Tarnished plant bugs, Lygus lineolaris (Palisot de Beauvois), were administered dosages of 0, 5, 10, 15, 20 and 40 krad of gamma-radiation from a 137Cs source (10 krad = 100 Gy). Reductions in egg hatch and egg-to-adult survival in both irradiated parents and their F1 progeny tended to be inversely proportional to dosage received. Hatch of eggs from untreated parents averaged 58.9% and fell to 4.6% when males were treated with 40 krad. Egg-to-adult survival was more severely curtailed than egg hatch, averaging 36.0% for untreated groups and 0% for 40 krad groups. F1 progeny exhibited greater reductions in egg hatch and egg-to-adult survival than their treated parents. Eggs from untreated females mated with F1 male progeny averaged 58.9% hatch for the untreated control compared with 18.5% for the 10 krad group and 0.9% for the 20 krad group. Egg-to-adult survival in the untreated control averaged 38.4% compared with 5.4% for the 10 krad group and 0.1% for the 20 krad group. F1 females were more susceptible to the effects of irradiation than F1 males. Mortality in the 5 and 10 krad groups was similar to the untreated control, but fell abruptly at 15 krad and again at 40 krad.
Pathogenicity of Metarhizium anisopliae and Beauveria bassiana against Phyllophaga crinita and Anomala flavipennis (Coleoptera: Scarabaeidae)
Authors: Rodríguez-del-Bosque L. A. , Silvestre F. , Hernández V. M. , Quiroz H. , Throne J. E.
Published: September 2017

Five isolates of Beauveria bassiana (Balsamo) Vuillemin and 3 isolates of Metarhizium anisopliae (Metschnikoff) Sorokin were tested against third-instar larvae of Phyllophaga crinita (Burmeister) and Anomala flavipennis Burmeister under laboratory conditions using the “maximum challenge test” protocol. The M. anisopliae strains were more virulent than the B. bassiana strains, with the isolates MAGL3N and MAGL4N of M. anisopliae causing the highest mortality in both white grub species. Regardless of scarab species, mortality caused by MAGL3N was >63% after 4 days and >96% after 10 days. The other strain of M. anisopliae, MAGC2N, also caused high mortality in A. flavipennis, but at a slower rate than MAGL3N. Median lethal time (LT50) for MAGL3N was 2.9 days for P. crinita and 3.0 d for A. flavipennis. The LT50 for MAGL4N was 5.3 d for P. crinita and 7.6 d for A. flavipennis while the LT50 for MAGC2N was 4.4 d for A. flavipennis. Metarhizium anisopliae is a potential biological control agent for P. crinita and A. flavipennis and should be further investigated for possible development.
Comparative Toxicity and Efficacy of Selected Insecticides in Field and Greenhouse Assays Against Tawny and Southern Mole Crickets (Orthoptera: Gryllotalpidae)
Authors: Brandenburg R. L. , Xia Y. , Watson B.
Published: September 2017

The toxicity of thiamethoxam against nymphs and adults of the tawny mole cricket, Scaptericus vicinus Scudder, and the southern mole cricket, S. borellii Giglio-Tos, was evaluated in the field and greenhouse. Thiamethoxam demonstrated varying levels of mole cricket control in the field studies. The performance of the insecticide appeared to be related to the application timing and formulation. Applications made in late June 1998 provided the best mole cricket control compared to the other two field studies. The LC50 and LC90 values of thiamethoxam against adult southern mole crickets were 1,816 and 9,978 ppm, respectively, using a greenhouse bioassay technique. Another greenhouse study indicated that thiamethoxam at application rates ranging from 154 to 616 g (ai)/ha did not provide acceptable control against medium sized nymphs (third to six instars) of tawny and southern mole crickets. An additional study with fipronil, bifenthrin, and deltamethrin compared mortality of the two species of mole crickets in greenhouse bioassays. In these assays, all insecticides resulted in different levels of mole cricket mortality between the two species. The use of bifenthrin resulted in significantly higher mortality of tawny than southern mole crickets.
A Non-Sticky Trap for Tarnished Plant Bug (Heteroptera: Miridae)
Authors: Villavaso Eric J.
Published: September 2017

A simple trap that does not require the use of sticky material to capture tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), is described. The 28 × 11 cm (diam) cylindrical trap was constructed by cutting and joining sections from two 2-L clear plastic soft drink bottles and gluing screened entrance cones from commercially-available boll weevil (Anthonomus grandis Boheman) traps in each end. Five sticky trap designs were tested, and the sticky trap that captured the most plant bugs was compared to the non-sticky trap. With virgin females plus green bean pods (Phaseolus vulgaris L.) as bait, the non-sticky traps captured only males, but females comprised 11% of the capture on the sticky traps. Females comprised 40% of the capture on sticky traps baited with green bean pods only. Opaque traps shaped like the clear traps were inferior to the clear traps. The non-sticky trap should facilitate testing of potential components of the pheromone of tarnished plant bug, and perhaps that of L. hesperus Knight. The combination of a synthetic plant bug pheromone and a non-sticky trap may lead to a practical method of monitoring or estimating populations.
Comparative Laboratory Rearing of Mecidea major and M. minor (Heteroptera: Pentatomidae)
Authors: Bundy C. Scott , McPherson J. E. , Smith Paul F.
Published: September 2017

The stink bugs Mecidea major Sailer and M. minor Ruckes were reared from egg to adult under controlled laboratory conditions at 25 ± 0.01 °C, 79.3 ± 0.05% humidity, and a photoperiod of LD 14:10 h, on Eragrostis lehmanniana Nees. The incubation period for M. major eggs averaged 5.67 d, and the five stadia 3.54, 5.56, 4.94, 5.62, and 9.63 d, respectively. The incubation period for M. minor eggs averaged 6.00 d, and the five stadia 3.20, 6.53, 4.48, 5.56, and 8.81 d, respectively. Total developmental time averaged 34.96 and 34.58 d for M. major and M. minor, respectively, and did not differ significantly between sexes within each species. However, it did differ within females between species.
Survey of the Spiders of Cotton in New Mexico with Seasonal Evaluations Between Bt and Non-Bt Varieties
Authors: Bundy C. Scott , Smith Paul F. , Richman David B. , Steiner Robert L.
Published: September 2017

The relative abundance of spiders was evaluated over two growing seasons among six large fields of cotton representing the major forms of cotton grown in New Mexico (conventional acala, Bt acala, conventional pima, and organic pima). Spiders were collected both from the foliage and from the ground surface. Forty-two genera of spiders in 19 families were identified. The most abundant spiders collected were wolf spiders, sheetweb spiders, crab spiders, ghost spiders, and meshweb weavers. Pardosa sternalis (Thorell) was the most common spider collected overall during this study. Seasonal comparisons of spider abundance between conventional and Bt cotton were not significantly different. However, significant month by variety interactions were observed for some species.
Effect of Weeds on Rice Stink Bug (Hemiptera: Pentatomidae) Populations in Florida Rice Fields
Authors: Cherry Ron , Bennett Andy
Published: September 2017

The effect of weeds on rice stink bug, Oebalus pugnax (F.), populations was studied in Florida rice fields. Fall panicum, Panicum dichotomiflorum Michaux, was the most common grassy weed found in weedy areas of rice fields, and significantly more rice stink bugs were found in these weedy areas vs nonweedy areas in the fields. Large numbers of rice stink bugs also were found in unmowed roadsides containing heading weeds, especially coast cockspur, Echinochloa walteri (Pursh) Heller. In contrast, few rice stink bugs were found in mowed roadsides which prevented weed heading around rice fields. Our study shows that weed control helps reduce rice stink bug populations in Florida rice.
A Survey of Five Stem-Feeding Insect Pests of Wheat in the Northern Great Plains
Authors: Shanower Thomas G. , Waters Debra K.
Published: September 2017

The wheat stem sawfly, Cephas cinctus Norton, the wheat stem maggot, Meromyza americana Fitch, the Hessian fly, Mayetiola destructor (Say), the wheat jointworm, Tetramesa tritici (Fitch), and the wheat strawworm, Tetramesa grandis (Riley), have long been considered wheat pests in the northern Great Plains. This paper reports results of surveys for these pests conducted over 3 yrs in parts of Montana (10 counties), North Dakota (14 counties), South Dakota (1 county), Nebraska (4 counties) and Wyoming (1 county). Fields were randomly selected and a mean of 191 stems were sampled from each field. The percentage of stems infested with each pest was recorded. The percentage of parasitized wheat stem sawfly larvae also was noted. The wheat stem sawfly, wheat stem maggot, and Hessian fly were the most commonly encountered pests, recorded in nearly every county. Wheat stem sawfly density was twice that of wheat stem maggot (7% vs 3.2%) in infested fields. Wheat stem sawfly densities exceeded 10% in 4 counties: Daniels and Wibaux in MT, Golden Valley, ND and Goshen, WY. Wheat stem sawfly parasitism was low and positively correlated with sawfly infestation. Wheat stem maggot infestations were low (<11% for all fields), averaging 3.2% among infested fields. Hessian fly densities were much lower (2.2% among infested fields) than reported elsewhere in the U.S. The wheat jointworm and strawworm were absent from most fields and only occasionally found at low levels (<1% and <3.5% respectively, among infested fields). This information will help to prioritize wheat insect pest management research and extension programs in this region.
An Improved Trap for Monitoring Stink Bugs (Heteroptera: Pentatomidae) in Apple and Peach Orchards
Authors: Hogmire Henry W. , Leskey Tracy C.
Published: September 2017

Capture of stink bugs (Heteroptera: Pentatomidae) in apple orchards with yellow pyramid traps baited with Euschistus spp. (Heteroptera: Pentatomidae) aggregation pheromone, methyl (2E,4Z)-decadienoate, was 4 fold greater when traps were topped with a 3.8-L jar with a 1.6 cm diameter opening and trimmed wire edging than with a 1.9-L jar with a 5 cm diameter opening with no wire edging. Stink bug capture in the 3.8-L jar top was unaffected by the presence or size of an insecticide ear tag, indicating that this improved design led to increased captures by reducing escape. Sixty-four percent fewer stink bugs escaped from 3.8-L jar tops with the improved capture mechanism than from the 1.9-L jar tops. Green stink bug, Acrosternum hilare (Say), was more susceptible to the presence of the insecticide ear tag than the brown stink bug, Euschistus servus (Say), with dusky stink bug, E. tristigmus (Say), exhibiting high mortality in traps with and without ear tags. Among baited and unbaited pyramid traps with different visual stimuli, fewer captures were recorded in black pyramid traps than in clear, yellow, green or white pyramid traps. Similar numbers of brown stink bugs were captured in yellow pyramid traps deployed on the ground between trees or on horizontal branches within trees in the orchard border row. Captures of dusky and green stink bugs were greater in the tree pyramid, especially from August to mid-October. Relationships between stink bug capture and injury will need to be determined before this trap can be incorporated as a decision-making tool in pest management programs.
Use of Entomopathogenic Nematodes (Steinernematidae) in Conjunction with Mulches for Control of Overwintering Codling Moth (Lepidoptera: Tortricidae)
Authors: Lacey Lawrence A. , Granatstein David , Arthurs Steven P. , Headrick Heather , Fritts Robert
Published: September 2017

Mulches were compared to test their utility for enhancing efficacy of entomopathogenic nematodes (EPNs) applied against over-wintering codling moth, Cydia pomonella (L.), larvae. Compared with bare ground, mulches may enhance control by providing cocooning sites for codling moth larvae and a substrate that is easy to treat, maintains moisture, and enhances nematode activity. Steinernema carpocapsae (Weiser) or S. feltiae (Filipjev) were applied at a rate of 2.5 × 109 infective juveniles (IJs)/ha against cocooned sentinel codling moth larvae in cardboard strips followed by 2 h of irrigation in plots that were covered with one of four mulches (clover, shredded paper, grass hay or wood chips) or to bare plots on 29 September 2003. Average mortalities of 97 and 98% were observed in paper-mulched plots treated with S. carpocapsae or S. feltiae IJs, respectively, compared to 80 and 76% mortality in bare plots. Larvicidal activity for S. feltiae against sentinel larvae in cardboard strips that were placed in crevices in the soil was nearly identical in all mulched and bare plots (97–100% mortality), but reduced for S. carpocapsae in wood chip and clover plots (76–79% mortality) relative to paper, grass hay and bare plots (93–97% mortality). A significant portion of sentinel larvae (25 and 14%) that were placed in crevices in the soil in hay- and paper-mulched control plots revealed the natural presence of EPNs (Heterorhabditis sp.). Applications of S. carpocapsae and S. feltiae at a reduced rate of 109 IJs/ha on 20 April 2004, followed by 1 h of irrigation resulted in 13.1 and 7.4% reduction in sentinel larvae in bare plots compared to 36 and 62% in mulched plots, respectively. Applications of S. carpocapsae and S. feltiae at a rate of 2.5 × 109 IJs/ha on 21 September 2004 to bare and wood chip-mulched plots followed by 1 h of irrigation resulted in 21 and 65% reduction in sentinel larvae in bare plots compared to 93 and 85% in mulched plots, respectively. Residual larvicidal activity of EPNs 3 d after applications in treated plots was low, but significant in the nonmulched plots (12–17% mortality) relative to untreated controls (1–2% mortality).
Boll Removal Studies Provide Insights into Compensation Ability of Virginia Cotton: A Necessary Step for Further Improvement of Insect Management Strategies
Authors: Herbert D. Ames , Malone Sean , Aref Susanne , Faircloth Joel , Abaye Ozzie
Published: September 2017

In developing management strategies for hemipteran pests in cotton (Gossypium hirsutum L.), it is important to understand the potential of plants to compensate for loss of the fruiting structures. Because of its northern latitude, Virginia has fewer available heat units relative to other cotton-producing states. Therefore, there may be limited opportunity for compensation relative to more southerly production areas. Previous work in Virginia demonstrated that cotton can sustain relatively high levels of first position square loss with no yield loss. This study evaluated the impact of a single event loss of 10–14-d-old bolls via mechanical removal on cotton lint yields with the premise that boll loss would have greater impact than square loss as less time and fewer heat units are available for compensation. Field experiments examining four levels of boll removal (0, 5,15 and 20%) were conducted in 2001,2002 and 2003. Each boll removal level was imposed at three different dates, beginning 2 wks after first flower and at 3- to 5-d intervals thereafter. Yields ranged from 1103–1422 in 2001, 909–1124 in 2002, and 843–1015 kg lint per ha in 2003. There were no significant differences in lint yields among the boll removal dates or removal levels. The results of our study showed that cotton in Virginia, which approaches the northernmost latitude for cotton production, is capable of sustaining losses as high as 20% of 10–14-d-old bolls at a single removal event without affecting lint yield. Results were consistent despite the wide variation in rainfall and temperatures during the 3 study years.
New Source of Leafhopper Resistance in Peanut
Authors: Branch William D. , Todd James W.
Published: September 2017

Field screening for potato leafhopper, Empoasca fabae Harris, resistance among peanut, Arachis hypogaea L., genotypes were conducted for three consecutive years (2001, 2002, and 2003) at the University of Georgia, Coastal Plain Experiment Station in Tifton, GA. Irrigated field trials were used for evaluations, and plants were grown without any pesticides other than preplant and occasional postemergence herbicides. Results from these replicated tests showed a wide-range of leafhopper damage. During each of the 3 yrs, ‘Georgia-01R’ consistently had the lowest leafhopper damage rating of all genotypes tested. Likewise, each year ‘Georgia Hi-O/L’ had the highest leafhopper damage rating. ‘Georgia Green’ and other cultivars and breeding lines were intermediate between Georgia-01R and Georgia Hi-O/L for leafhopper ratings. These field trials confirmed the multiple-pest resistant runner-type cultivar Georgia-01R as a new source of leafhopper resistance in peanut.
Influence of Transgenic Corn Expressing Insecticidal Protein of Bacillus thuringiensis Berliner on Natural Populations of Corn Earworm (Lepidoptera: Noctuidae) and Southwestern Corn Borer (Lepidoptera: Crambidae)
Authors: Allen Kerry C. , Pitre Henry N.
Published: September 2017

A 2-yr study was conducted to measure the influence of transgenic corn, Zea mays L., expressing the CrylAb endotoxin of Bacillus thuringiensis (Berliner) (Bt) by means of Event MON810 on natural populations of Helicoverpa zea (Boddie) and Diatraea grandiosella (Dyar). The studies were conducted at Leland and Morgan City, MS, in 1999 and at Morgan City in 2000. Although total numbers of H. zea larvae were not significantly different on transgenic corn hybrids compared with their near-isogenic parent lines, fewer large larvae were found on the transgenic hybrids. Differences in H. zea larval growth were noticeable when larvae fed on Bt corn vs non-Bt corn. The delay in larval growth for insects within a single generation, which could possibly result in asynchronous mating between insecticide resistant and susceptible insects, was observed for larvae feeding on plants expressing the Bt toxin. Diatraea grandiosella caused limited damage to the transgenic corn hybrids compared with their near-isogenic parent lines. Yields were not significantly greater for the Bt corn hybrids compared with their near-isogenic parent lines. Yields were not significantly greater for the Bt corn hybrids compared with the near-isogenic, non-Bt corn parents; however, there was a trend toward higher yields for Bt hybrids compared with their near-isogenic non-Bt parents.
Tobacco as a Trap Crop for Heliothis virescens (F.) (Lepidoptera: Noctuidae) in Cotton
Authors: Tillman P. Glynn
Published: September 2017

A 3-yr study evaluated tobacco as a trap crop for the tobacco budworm, Heliothis virescens (F.), in cotton. Small plot experiments were conducted on an experimental farm at Mississippi State University in Starkville, MS, in 1996 and on a commercial farm in Aliceville, AL, in 1997 to determine the ability of small strips of tobacco to trap H. virescens in cotton field plots. In the 1996 experiment, tobacco budworms eggs were significantly higher on tobacco than on cotton from 7 June through 19 June and from 10 July through 22 July. In 1997, H. virescens eggs were significantly higher on tobacco than on cotton for every sampling date throughout the growing season. The conclusion derived from these small plot experiments was that H. virescens females preferred tobacco over cotton as an ovipositional site. Therefore, in 1998, a large-scale field experiment was conducted to determine the effectiveness of tobacco as a trap crop for H. virescens in commercial cotton fields in Funston, GA. In this experiment, the number of H. virescens eggs was significantly lower in cotton fields with tobacco trap crops compared to control cotton fields without tobacco trap crops on 2 and 9 July. Also, economic threshold for H. virescens was not reached in these cotton fields with tobacco trap crops. In contrast, the economic threshold for this pest was met in cotton fields without tobacco trap crops on two dates during the growing season. For each year of the study, percentage total real mortality (rx) for eggs and larvae of H. virescens on tobacco was very high, ranging from 91.4–99.9%. Larval mortality was attributed in part to parasitization by Toxoneuron nigriceps (formerly Cardiochiles nigriceps) Viereck and Campoletis sonorensis Cameron and an infection by an ascovirus of H. virescens. Thus, tobacco served as a trap crop and sink for H. virescens in cotton in this study.
Distribution and Size of Imported Fire Ant (Hymenoptera: Formicidae) Mounds in Recently Invaded Ball-and-Burlap Nurseries in Tennessee
Authors: Vogt James T. , Oliver Jason A.
Published: September 2017

A study was undertaken to describe size and distribution of imported fire ant mounds in south-central Tennessee ball-and-burlap plant nurseries to (1) improve survey and control measures and (2) assess the feasibility of airborne remote sensing for mound detection. Mounds were most numerous along roadsides and road cuts. Mounds in planted areas were larger than mounds along roadsides and road cuts, and mounds in open, grassy areas were of intermediate size (mean above-ground volume = 8.14, 4.36 and 5.32 L, respectively). An examination of mound size distribution in nursery landscapes indicated colony age-structure may not be consistent between landscape-date combinations, and mean mound size was smaller in July 2004 than in October 2003.
Effect of Formulated Insecticides on Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae) and its Parasitoid Gonatocerus ashmeadi Girault (Hymenoptera: Mymaridae)
Authors: Lauzière Isabelle , Elzen Gary
Published: September 2017

Eleven insecticides were tested using a bioassay of foliar insecticide residue to evaluate their impact on Homalodisca vitripennis nymphs and adults and on Gonatocerus ashmeadi parasitoid pupae and newly-emerged adults. Most compounds caused 100% mortality of H. vitripennis nymphs and adults within the first 24 h following exposure. Dimethoate was significantly less toxic to the nymphs than the other compounds. The insect growth regulators buprofezin and pyriproxifen caused high mortality levels at the end of the 72-h period of observation. They were efficacious against both the H. vitripennis nymphs and adults. Thiamethoxam, acetamiprid, cyfluthrin, fenpropathrin and endosulfan severely affected the immatures and newly-emerged adults of the parasitoid G. ashmeadi with total percent mortality exceeding 65%. Piriproxifen, methomyl, imidacloprid and carbaryl were moderately toxic to the parasitoid pupae and young adults (34–55% total mortality); whereas treatments using buprofezin or dimethoate allowed >89% survival of the parasitoids. These results may help predict the reliability of these compounds in the field and risks to natural enemies associated with their use. It is possible, however, to choose insecticides that are more selective in toxicity to the glassy-winged sharpshooter than to its natural enemies.
Effects of Nitrogen Fertility on Bt Endotoxin Levels in Maize
Authors: Bruns H. Arnold , Abel Craig A.
Published: September 2017

Three Bt maize hybrids (two with Bt event MON-810, one with Bt event DBT-418) and one nonBt maize hybrid were grown at Stoneville, MS, USA in 2002 and 2003 with N-fertility rates of 0, 112, 224, and 336 kg N/ha, respectively. Tissue samples of the 7th leaf at growth stage V5 (5 fully extended leaves) and primary ear leaf sheaths and outer ear husks at growth stage R3 (milk) were collected and analyzed for endotoxin concentrations. At V5 CrylAb Bt concentrations of the MON-810 hybrids increased whereas there were no N-fertility effects on Cry1Ac in the DBT-418 hybrid. Bioassays from tissue samples at growth stage V5 of all N-fertility treatments for both Bt events were nearly 100% fatal to southwestern corn borer larvae (Diatraea grandiosella_Dyar). Endotoxin concentrations at growth stage R3 increased in both the primary ear leaf sheaths {[Bt] = 0.0006(kg N/ha) + 0.167 r2 = 0.8817 for both MON-810 and DBT-418} and outer ear husks {[Bt] = 0.0006(kg N/ha) + 0.148) r2 = 0.9985 and [Bt] = 0.0007 (kg N/ha) + 0.16) r2 = 0.8702 for MON-810 and DBT-418, respectively} as N fertilization increased in 2003. Bioassays determined that southwestern corn borers were susceptible to even the lowest [Bt] in tissues of MON-810 at R3 but not DBT-418. Diets made from the nonBt hybrid at all stages and N-fertility rates had a nearly 80.0% larval survival rate. Because other Noctuidae pests [i.e., corn earworm (Heliothis zea (Boddie)) and fall armyworm (Spodoptera frugiperda (J. E. Smith))] of corn are more tolerant to Bt toxins, growing Bt maize under adequate levels of N-fertility may be even more important to insure maximum protection from these pests.
Photosynthesis in Wheat at the Grain Filling Stage Is Altered by Larval Wheat Stem Sawfly (Hymenoptera: Cephidae) Injury and Reduced Water Availability
Authors: Macedo Tulio B. , Weaver David K. , Peterson Robert K. D.
Published: September 2017

The impact of larval feeding by wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), and reduced water availability on the photosynthesis and primary metabolism of wheat, Triticum aestivum (L.), was evaluated at the grain-filling developmental stage. Photosynthetic parameters measured included photosynthesis (Ps), stomatal conductance (gs), and transpiration (E) in the flag leaves. The parameters were measured at 4 wks after the treatments were imposed. Additional concomitant chlorophyll a fluorescence measurements were taken using both dark- and light-adapted tests. Photosynthesis was significantly affected by C. cinctus injury and suboptimal water availability. However, no significant interaction was observed between the two treatment factors. Plants under a reduced or suboptimal watering regime had Ps rates that were 43.7% lower than plants that were watered daily. We also observed a 12% higher Ps rate in uninfested plants compared to plants infested by C. cinctus. Several chlorophyll a fluorescence parameters also were affected by C. cinctus. Specifically, reductions in the photochemical efficiency of photosystem II (PSII) of C. cinctus infested plants were observed for plants under reduced water availability. This study demonstrates that wheat plants at the grain filling stage have reduced photosynthetic capacity when watered less frequently or when subjected to C. cinctus larval feeding injury. Less frequent watering and larval feeding injury did not have significant impacts on yield in this greenhouse study.
Deterrency and Toxicity of Essential Oils to Argentine and Red Imported Fire Ants (Hymenoptera: Formicidae)
Authors: Wiltz Beverly A. , Suiter Daniel R. , Gardner Wayne A.
Published: September 2017

Laboratory assays were conducted to evaluate deterrency and contact toxicity of six essential oils to the Argentine ant, Linepithema humile (Mayr), and the red imported fire ant, Solenopsis invicta Buren. In choice tests, both Argentine ants and fire ants crossed barriers treated with multiple rates of basil, citronella, lemon, peppermint, or tea tree oil less frequently than paired control barriers. Eucalyptus oil did not prevent movement of either species at any of the rates tested. In continuous exposure assays, citronella oil killed 50% of Argentine ants in 34.3 min and was the only treatment to cause 100% Argentine ant mortality after 24 h. Argentine ant mortality after 24 h was 89.8% with peppermint oil and 85.7% with tea tree oil, with the remaining treatments having mortality not significantly different from the control. Only citronella oil caused significant mortality of red imported fire ants, with 50.6% of the ants being dead after 24 h of continuous exposure.
Effect of Pesticide Mixtures on the Survival of the Predatory Mite Neoseiulus cucumeris (Acarina: Phytoseiidae)
Authors: Lash Heather E. , Warnock Daniel F. , Cloyd Raymond A.
Published: September 2017

This study was conducted to determine the effect of 2 insecticides/miticides, spinosad and abamectin, and 2 fungicides, thiophanate-methyl and fenhexamid, when applied alone or mixed in all combinations, on the survival of Neoseiulus cucumeris (Oudemans). Neoseiulus cucumeris is a predatory mite utilized in greenhouses for managing western flower thrips, Frankliniella occidentalis Pergande. The deutonymph and adult stages of N. cucumeris were directly exposed to the pesticide treatments or a water control. Overall, the deutonymphs were more susceptible to the pesticide treatments, based on percent survival 24 h after treatment, than the adults. Five of the 7 pesticide mixtures containing spinosad and 4 of the 7 mixtures containing abamectin resulted in deutonymph mortality values between 50 and 69%. Thiophanate-methyl alone and in combination with either spinosad or abamectin resulted in >35% mortality of the deutonymphs. Based on the results of this study, spinosad and abamectin, when used alone or in mixture with thiophanate-methyl will reduce N. cucumeris populations by killing the deutonymphs. This information is important to greenhouse managers who want to use pesticide mixtures to manage arthropod pests and fungal pathogens without disrupting biological control programs for western flower thrips.