Multiyear insecticide efficacy for redbanded stink bug control in Louisiana soybean

The redbanded stink bug,Piezodorus guildinii, is the most economically damaging insect pest of soybean in Louisiana. Effective management strategies are crucial for sustainable soybeanproduction. This study investigated the efficacy of various insecticide treatments against P. guildinii over four consecutive growing seasons (2022, 2023, 2024, and 2025). Field trials were conducted at the Dean Lee Research and Extension Center in Alexandria, Louisiana following a randomized block design with four blocks and one replicate per block. Treatments included stand alone and tank-mixed products. Insecticide applications were timed based on established economic thresholds of four P. guildinii nymphs/adults per 25 sweeps. Stink bug numbers were evaluated at 3, 7, and 14 (±3) days after treatment. Across the four-year study, the combination of acephate and bifenthrin consistently provided the most effective control of P. guildinii, reducing insect numbers compared to other treatments. Acephate and bifenthrin applied offered adequate control depending on pest pressure and environmental conditions.Although not yet registered, Plinazolin provided the longest residual activity. This research provides valuable data for developing integrated pest management programs, emphasizing the importance of insecticide rotation and strategic use of effective combinations to mitigate the impact of P. guildinii on soybean yields.