US-IALE 2018

AUTHORS: Dawn Olson, Crop Protection and Research Management Unit, USDA-ARS; Kristina Prescott, Department of Ecology, Evolution and Behavior, University of Minnesota; Adam Zeilinger, Department of Environmental Science, Policy and Management, University of California, Berkeley; Suqin Hou, Department of Biostatistics, Harvard T. H. Chan School of Public Health; Alisa Coffin*, Southeast Watershed Research Laboratory, USDA-ARS; Coby Smith, Southeast Watershed Research Laboratory, USDA-ARS; John Ruberson, Department of Entomology, Kansas State University; David Andow, Department of Entomology and Center for Community Genetics, University of Minnesota

ABSTRACT: Landscape factors can significantly influence arthropod natural enemy and herbivore pest populations. The economically important brown stink bug, Euschistus servus, is a native mobile, polyphagous and multivoltine pest of many crops in southeastern USA and understanding the relative influence of local and landscape factors on their reproduction may facilitate population management. We determined the influence of the percentage area of non-crop and major crops in the landscape, the connectivity of major crops, the identity of major crops and stink bug egg predator density on E. servus reproduction. Finite rate of population increase (?) was estimated in four major crop hosts—maize, peanut, cotton and soybean—over three years in 16 landscapes of southern Georgia. A geographic information system (GIS) was used to characterize the surrounding landscape structure. LASSO regression was used to identify the subset of local and landscape characteristics and predator densities that account for variation in ?. The percentage area of maize, peanut and woodland and pasture in the landscape and the connectivity of cropland had no influence on E. servus ?. The best model for explaining variation in ? included only four predictor variables: whether or not the sampled field was a soybean field, mean natural enemy density in the field, percentage area of cotton in the landscape and the percentage area of soybean in the landscape. Soybean was the single most important variable for determining E. servus ?, with much greater reproduction in soybean fields than in other crop species.