Differential stink bug pyrethroid sensitivity associated with landscape composition in North Carolina soybean

The arrangement of crop hosts in the landscape plays a role in polyphagous pest exposure to multiple chemical applications that can affect resistance selection. Stink bugs are a group of polyphagous pest species that utilize both crop and noncrop hosts throughout the growing season, leading to insecticide exposure in different crops. The spatiotemporal arrangement of common crop hosts creates a mosaic of host patches that are infested by stink bugs during the growing season in eastern North Carolina. This study explored the relationship between stink bug insecticide susceptibility and landscape composition in that region. Stink bug populations were collected from 35 locations from 2022 to 2024 in eastern North Carolina. A glass-vial bioassay procedure was used to evaluate bifenthrin susceptibility of Euschistus servus Say (brown stink bug), Chinavia hilaris Say (green stink bug), and Nezara viridula L. (southern green stink bug). We then used a geospatial approach to explore the relationship between insecticide susceptibility of stink bug species and landscape-level availability of host crops where bifenthrin is commonly used. Our results showed that in bifenthrin susceptibility differed among stink bug populations. Species level susceptibility was not consistently related to the abundance and frequency of their host crops. Stink bug susceptibility to bifenthrin reported here will provide the baseline data in future resistance monitoring programs.