Population densities, field colonization behavior, and site-specific insecticide applications for redbanded stink bug control

Prior to 2000, the redbanded stink bug, Piezodorus guildinii (Westwood), had not been an economic threat to soybean production in the U.S. Now, redbanded stink bug has spread throughout Louisiana and is the dominant stink bug species, comprising 59 to 72% of total species found in soybean. In response, production inputs have significantly risen due to increased insecticide applications for this pest. Field colonization behavior of many stink bugs is known to be aggregated. However, for the redbanded stink bug, specific field distributions and densities are unknown. If this pest demonstrates aggregated distributions and/or is concentrated within field margins, site-specific targeting of insecticide applications is possible. This could reduce pesticide applications, saving growers money while conserving natural enemies. Research efforts focused on mapping and analyzing redbanded stink bug population densities and distributions within fields and the adjacent landscape. Redbanded stink bug numbers were assessed during early vegetative stages through R7 in commercial soybean fields (10 acre) and small research plots (0.5 acre) using a sweep net and a grid-based sampling design. Preliminary results indicate that stink bugs are aggregated along field edges early (R1) in the season. Applications along field edges reduced field colonization by two weeks and reduced overall stink bug populations when soybeans had reached R6; 14 per 25 sweeps on field edges compared to 0 per 25 sweeps in field interior. Site-specific insecticide applications for stink bug control reduced total insecticide applications by 50% and yielded equal to whole fields treated for these pests.