Factors affecting spatial patterns of brown marmorated stink bug, Halyomorpha halys, in peach orchard

Brown marmorated stink bug, Halyomorpha halys (Stål), an invasive pest of multiple crops in the mid-Atlantic region, has caused significant reductions in crop yield. Its ability to overwinter in forested areas and structures coupled with its wide host range have allowed it to rapidly establish populations on New Jersey farms since its introduction in 1996. Knowledge of its spatial pattern within orchards and the factors that may influence its distribution will allow for focused control efforts. By understanding how H. halys moves within orchards, locations susceptible to establishment by this pest can be determined and targeted. The distribution and movement of H. halys in peach orchards was investigated during the summers of 2012 and 2013. Orchards containing between 100 and 300 trees were surveyed weekly for H. halys at a fine scale, with every tree being surveyed. These data were mapped using GIS (Geospatial Information Systems) software. Ripley’s K statistics were calculated to determine if clustering of populations exists within each orchard, and a semivariogram was drawn to display the degree of spatial autocorrelation. Spatial autoregressive models were used to determine if factors such as variety or distance from the edge have an effect on the level and location of the populations. Preliminary results indicate clustering of populations and some spatial autocorrelation between sample points at small inter-tree distances. These findings are a step towards developing a strategy that can be used to more effectively manage H. halys on farms.