Optimizing unprecedented systemic insecticide soil-drenching doses for controlling Bemisia tabaci (Gennadius): Balancing efficacy and soil health in Cucurbita pepo L. cropping

Abstract The study aimed to explore a reliable soil-drench application of acetamiprid 70% WG and cyantraniliprole 20% SC for controlling Bemisia tabaci (Gennadius, 1889) on squash plants. The safest field dosages, amongst presumptive dosages, on the vascular bundle and chlorophyll of treated plants were evaluated. Total reductions in whitefly adults by acetamiprid 70% WG (85.8 and 92.8%) surpassed cyantraniliprole 20% SC (67.1 and 74.1%) during two seasons. Equal reductions in nymphs occurred, except in the first season, where acetamiprid 70% WG (97.40%) transcended cyantraniliprole 20% SC (94.6%). In both seasons, the mortalities of earthworm, Eisenia fetida (Savigny, 1826) expressed moderately harmful effect by acetamiprid 70% WG in the top (66.88 and 61.25%) and deep (53.13 and 52.50%) soil-layers. Cyantraniliprole 20% SC was slightly harmful in the top (30.00 and 29.38%) and harmless in the deep (18.13 and 15.00%) layers. Persistency of acetamiprid 70% WG long-lasted in deep layers, unlike cyantraniliprole 20% SC receded in top layers. Levels of soil-respiration in the control were unusually high, and almost unusually high for acetamiprid 70% WG, whereas cyantraniliprole 20% SC was almost ideal. Therefore, soil-drenching of these insecticides could be successfully employed for controlling B. tabaci and affording safety to the agricultural environment.