Browsing by Author "Dively, G. P."

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    Comparison of Two Sampling Methods for Assessing Halyomorpha halys (Hemiptera: Pentatomidae) Numbers in Soybean Fields
    Aigner, Benjamin L.; Herbert, D. A.; Dively, G. P.; Venugopal, D.; Whalen, J.; Cissel, B.; Kuhar, Thomas P.; Brewster, C. C.; Hogue, J. W.; Seymore, E. (Oxford University Press, 2016-12-01)
    Sampling soybean fields for the brown marmorated stink bug, Halyomorpha halys Sta° l (Hemiptera: Pentatomidae), can be challenging. Both adults and nymphs have a "startle response" and drop to the ground with even the slightest disturbance. This behavior could reduce the effectiveness of the traditional sweep net and ground cloth sampling methods. In 2013 and 2014, in Virginia, Delaware, and Maryland, we evaluated a visual plant inspection method that consisted of counting the number of brown marmorated stink bug nymphs and adults seen on soybean plants in a 2-min inspection period while walking carefully between two rows. After a 30-min interval, which allowed the stink bugs to reposition in the canopy, the area was resampled using 15 sweeps with a 38-cm-diameter sweep net. In total, 76 soybean fields and 2,042 paired comparisons were used to determine a strong linear relationship between sampling methods (y = 0.984x + 0.4359, R2 = 0.6934, where y = brown marmorated stink bugs/2-min visual count and x = brown marmorated stink bugs/15 sweeps). An average visual count of 5.4 brown marmorated stink bugs in 2 min was estimated as being equivalent to the current economic threshold of 5 stink bugs per 15 sweeps. Visual inspection appears to be an effective method for assessing brown marmorated stink bug populations in soybeans.
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    Halyomorpha halys (brown marmorated stink bug)
    Leskey, Tracy C.; Hamilton, G. C.; Biddinger, D. J.; Buffington, M. L.; Dieckhoff, C.; Dively, G. P.; Fraser, H.; Gariepy. T.; Hedstrom, C.; Herbert, D. Ames Jr.; Hoelmer, K. A.; Hooks, C. R. R.; Inkley, D.; Krawczyk, G.; Kuhar, Thomas P.; Lee, D.-H.; Nielsen, Anne L.; Pfeiffer, Douglas G.; Rodriguez-Saona, C.; Shearer, Peter W.; Talamas, E.; Tomasino, E.; Tooker, J.; Venugopal, P. D.; Whalen, J.; Walton, V.; Makkouk, K.; Wiman, M. (2014-09-19)
    Following the accidental introduction and initial discovery of H. halys in Allentown, Pennsylvania, USA, this species has been detected in 41 states and the District of Columbia in the USA. Isolated populations also exist in Switzerland, France, Italy and Canada. Recent detections also have been reported in Germany and Liechtenstein. BMSB has become a major nuisance pest in the mid-Atlantic region and Pacific Northwest, USA, due to its overwintering behaviour of entering human-made structures in large numbers. BMSB also feeds on numerous tree fruits, vegetables, field crops, ornamental plants, and native vegetation in its native and invaded ranges. In the mid-Atlantic region, serious crop losses have been reported for apples, peaches, sweetcorn, peppers, tomatoes and row crops such as field maize and soyabeans since 2010. Crop damage has also been detected in other states recently including Oregon, Ohio, New York, North Carolina and Tennessee.
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    Natural History, Ecology and Management of the Mexican Bean Beetle (Coleoptera: Coccinellidae) in the United States
    Schultz, P. B.; Herbert, D. Ames Jr.; Kuhar, Thomas P.; Nottingham, Louis B.; Dively, G. P. (2016-01-01)
    Mexican bean beetle, Epilachna varivestis Mulsant, is an invasive, phytophagous ladybeetle that has occurred in the United States since the late 1800s. In the 1970s, it was a major defoliating pest of soybeans in the eastern United States, before populations mysteriously crashed. Today, the insect remains a devastating pest of Phaseolus species, such as common bean, P. vulgaris, and lima bean, P. lunatus, in geographic locations with moderate summer temperatures and regular rainfall, such as the Mid-Atlantic and southern Appalachian Mountain regions of the United States. Larvae and adults injure plants by consuming leaf tissue, which promotes desiccation and decreases photosynthetic activity. Beetle damage can be successfully mitigated with various insecticides (both conventional and organic), or via augmentative releases of the biological control agent, Pediobius foveolatus (Crawford). Various cultural and mechanical management tactics also exhibit management potential; however, more research is necessary to determine specific criteria for effective implementation of these strategies. This paper will review the general biology of Mexican bean beetle, management options to mitigate crop damage, and its historical timeline as a pest in the United States.
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    Pest status of the brown marmorated stink bug, Halyomorpha halys in the USA
    Leskey, Tracy C.; Hamilton, G. C.; Nielsen, Anne L.; Polk, D. F.; Rodriguez-Saona, C.; Bergh, J. Christopher; Herbert, D. Ames Jr.; Kuhar, Thomas P.; Pfeiffer, Douglas G.; Dively, G. P.; Hooks, C. R. R.; Raupp, M. J.; Shrewsbury, Paula M.; Krawczyk, G.; Shearer, Peter W.; Whalen, J.; Koplinka-Loehr, C.; Myers, Elizabeth; Inkley, D.; Hoelmer, K. A.; Lee, D.-H.; Wright, S. E. (2012-10-01)
    Since its initial discovery in Allentown, PA, USA, the brown marmorated stink bug (BMSB), Halyomorpha halys (Heteroptera: Pentatomidae) has now officially has been detected in 38 states and the District of Columbia in the USA. Isolated populations also exist in Switzerland and Canada. This Asian species quickly became a major nuisance pest in the mid-Atlantic USA region due to its overwintering behavior of entering structures. BMSB has an extremely wide host range in both its native home and invaded countries where it feeds on numerous tree fruits, vegetables, field crops, ornamental plants, and native vegetation. In 2010, populations exploded causing severe crop losses to apples, peaches, sweet corn, peppers, tomatoes and row crops such as field corn and soybeans in several mid-Atlantic states. Damaging populations were detected in vineyards, small fruit and ornamentals. Researchers are collaborating to develop management solutions that will complement current integrated pest management programs. This article summarizes the current pest status and strategies being developed to manage BMSB in the USA.
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    Sweet Corn Sentinel Monitoring for Lepidopteran Field-Evolved Resistance to Bt Toxins
    Dively, G. P.; Kuhar, Thomas P.; Taylor, Sally V.; Doughty, H. B.; Holmstrom, K.; Gilrein, D.; Nault, B. A.; Ingerson-Mahar, J.; Whalen, J.; Reisig, D.; Frank, Daniel L.; Fleischer, S. J.; Owens, David; Welty, C.; Reay-Jones, F. P. F.; Porter, P.; Smith, J. L.; Saguez, J.; Murray, S.; Wallingford, A.; Byker, H.; Jensen, B.; Burkness, E.; Hutchison, W. D.; Hamby, K. A. (Oxford University Press, 2021-02-01)
    As part of an insect resistance management plan to preserve Bt transgenic technology, annual monitoring of target pests is mandated to detect susceptibility changes to Bt toxins. Currently Helicoverpa zea (Boddie) monitoring involves investigating unexpected injury in Bt crop fields and collecting larvae from non-Bt host plants for laboratory diet bioassays to determine mortality responses to diagnostic concentrations of Bt toxins. To date, this monitoring approach has not detected any significant change from the known range of baseline susceptibility to Bt toxins, yet practical field-evolved resistance in H. zea populations and numerous occurrences of unexpected injury occur in Bt crops. In this study, we implemented a network of 73 sentinel sweet corn trials, spanning 16 U.S. states and 4 Canadian provinces, for monitoring changes in H. zea susceptibility to Cry and Vip3A toxins by measuring differences in ear damage and larval infestations between isogenic pairs of non-Bt and Bt hybrids over three years. This approach can monitor susceptibility changes and regional differences in other ear-feeding lepidopteran pests. Temporal changes in the field efficacy of each toxin were evidenced by comparing our current results with earlier published studies, including baseline data for each Bt trait when first commercialized. Changes in amount of ear damage showed significant increases in H. zea resistance to Cry toxins and possibly lower susceptibility to Vip3a. Our findings demonstrate that the sentinel plot approach as an in-field screen can effectively monitor phenotypic resistance and document field-evolved resistance in target pest populations, improving resistance monitoring for Bt crops.