Browsing by Author "Joseph, Shimat V."

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    Characterizing spring emergence of adult Halyomorpha halys using experimental overwintering shelters and commercial pheromone traps
    Bergh, J. Christopher; Morrison, William R. III; Joseph, Shimat V.; Leskey, Tracy C. (2017-03)
    To improve our understanding of adult Halyomorpha halys (Stal) (Hemiptera: Pentatomidae) overwintering biology and to better inform models of its population dynamics, its temporal pattern of spring emergence was investigated using experimental overwintering shelters in screened cages within protective structures. In 2012, plastic shelters containing 100 adults were deployed in unheated, unlighted buildings, and adjacent woodlots in Virginia, USA. In 2013 and 2014, wooden shelters containing 300 paint-marked adults were deployed in pairs in six woodlots across Virginia, West Virginia, and Maryland, USA; one in a closed cage and one in a cage with the top removed, enabling emerged adults to be counted or to disperse, respectively. In 2013 and 2014, pheromone-baited and non-baited pyramid traps encircled the shelters at each site. Regular counts of adults that emerged into the closed cage and of marked and wild' (unmarked) adults captured in traps were conducted from February or March through early July. In 2012, emergence patterns from shelters in buildings and woodlots were very similar and matched those recorded from woodlots in 2013 and 2014. In all years, a small peak of emergence occurred in about mid-April, a larger and more prolonged peak was observed between mid-May and early June, and emergence ended by early July. Of the 449 H.halys adults captured in traps between 2013 and 2014, only three were marked individuals from shelters in the open cage, suggesting that adults emerging from overwintering sites may require a dispersal flight before responding to pheromone-baited traps. In 2013 and 2014, respectively, 98 and 93% of captures were in pheromone-baited traps, but there was no correlation between the weekly number of adults that emerged from shelters in the closed cages and captures in traps.
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    Effect of pre-harvest exposures to adult Halyomorpha halys (Hemiptera: Pentatomidae) on feeding injury to apple cultivars at harvest and during post-harvest cold storage
    Bergh, J. Christopher; Joseph, Shimat V.; Short, Brent D.; Nita, Mizuho; Leskey, Tracy C. (2019-10)
    The effect of exposing apples to brown marmorated stink bug, Halyomorpha halys, for discrete intervals before harvest and of post-harvest cold storage on feeding injury expression was evaluated in 2011 and 2012. Individual apples from four cultivars in experimental orchards in Virginia and West Virginia, USA were caged soon after fruit set to protect them from insect injury. During each of the four weeks preceding harvest of each cultivar, five adult H. halys were placed in a subset of cages for 7-days, then removed. Control fruit were not exposed. The proportion of injured fruit and the number of external injuries was evaluated at harvest, after which the fruit were held in cold storage for about 5 weeks, followed by assessments of the proportion of fruit injured and the number of external and internal injuries. Most exposure timings resulted in external injury at harvest, but fruit exposed closer to harvest tended to show less injury than those exposed earlier. Fruit from all cultivars showed external injury at harvest, with variation in the proportion of injured fruit among them. The proportion of injured fruit and the number of external injuries tended to increase during post-harvest cold storage in some, but not all cultivars. The number of external injuries at harvest and after cold storage underrepresented the number of internal injuries. Results are discussed in the relation to the length of pre-harvest protection required to mitigate fruit injury from H. halys.
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    Evaluating invasion risk and population dynamics of the brown marmorated stink bug across the contiguous United States
    Illán, Javier Gutierrez; Zhu, Gengping; Walgenbach, James F.; Acebes-Doria, Angel; Agnello, Arthur M.; Alston, Diane G.; Andrews, Heather; Beers, Elisabeth H.; Bergh, J. Christopher; Bessin, Ricardo T.; Blaauw, Brett R.; Buntin, G. David; Burkness, Erik C.; Cullum, John P.; Daane, Kent M.; Fann, Lauren E.; Fisher, Joanna; Girod, Pierre; Gut, Larry J.; Hamilton, George C.; Hepler, James R.; Hilton, Richard; Hoelmer, Kim A.; Hutchison, William D.; Jentsch, Peter J.; Joseph, Shimat V.; Kennedy, George G.; Krawczyk, Grzegorz; Kuhar, Thomas P.; Lee, Jana C.; Leskey, Tracy C.; Marshal, Adrian T.; Milnes, Joshua M.; Nielsen, Anne L.; Patel, Dilani K.; Peterson, Hillary D.; Reisig, Dominic D.; Rijal, Jhalendra P.; Sial, Ashfaq A.; Spears, Lori R.; Stahl, Judith M.; Tatman, Kathy M.; Taylor, Sally V.; Tillman, Glynn; Toews, Michael D.; Villanueva, Raul T.; Welty, Celeste; Wiman, Nik G.; Wilson, Julianna K.; Zalom, Frank G.; Crowder, David W. (Wiley, 2022-11-01)
    BACKGROUND: Invasive species threaten the productivity and stability of natural and managed ecosystems. Predicting the spread of invaders, which can aid in early mitigation efforts, is a major challenge, especially in the face of climate change. While ecological niche models are effective tools to assess habitat suitability for invaders, such models have rarely been created for invasive pest species with rapidly expanding ranges. Here, we leveraged a national monitoring effort from 543 sites over 3 years to assess factors mediating the occurrence and abundance of brown marmorated stink bug (BMSB, Halyomorpha halys), an invasive insect pest that has readily established throughout much of the United States. RESULTS: We used maximum entropy models to estimate the suitable habitat of BMSB under several climate scenarios, and generalized boosted models to assess environmental factors that regulated BMSB abundance. Our models captured BMSB distribution and abundance with high accuracy, and predicted a 70% increase in suitable habitat under future climate scenarios. However, environmental factors that mediated the geographical distribution of BMSB were different from those driving abundance. While BMSB occurrence was most affected by winter precipitation and proximity to populated areas, BMSB abundance was influenced most strongly by evapotranspiration and solar photoperiod. CONCLUSION: Our results suggest that linking models of establishment (occurrence) and population dynamics (abundance) offers a more effective way to forecast the spread and impact of BMSB and other invasive species than simply occurrence-based models, allowing for targeted mitigation efforts. Implications of distribution shifts under climate change are discussed.