Dispersal pattern and dispersion of adult and nymph stink bugs (Hemiptera: Pentatomidae) in wheat and corn.

Euschistus servus (Say) can develop a generation on wheat, Triticum aestivum L., before moving to corn, Zea mays L., where it can be a pest. Because effective management methods are unknown, this study sought to describe the spatial distribution and dispersal of E. servus in the wheat and corn interface. In addition, Oebalus pugnax (F.) densities were documented in both crops. Wheat fields adjacent to the corn were sampled before harvest and stink bugs were marked using a product containing egg whites. Dispersal into the adjacent corn was measured using grid sampling, and dispersion was measured over time using an immunoassay targeting egg albumin on E. servus collected in corn. Dispersion was measured using Anselin Local Moran's I for unmarked stink bugs only. O. pugnax was prominent in wheat but was rarely recovered from corn. In contrast, E. servus was common in wheat during both years and dispersed into the adjacent corn. E. servus nymph and adult densities increased quadratically over time in corn in 2011. In contrast, E. servus nymph densities decreased over time in corn in 2012, while adult densities remained static. Most aggregations of E. servus nymphs and adults were located on the edge of the corn, directly adjacent to the harvested wheat. This is likely the first study to directly document the movement of E. servus nymphs to the adjacent crop. Movement from wheat to corn was not consistent between the years and may have been influenced by factors such as variations in weather, timing of wheat harvest, or other available alternative hosts.