Efficacy of an indigenous entomopathogenic fungus, Aschersonia aleyrodis, in controlling Bemisia tabaci on soybean

Abstract Bemisia tabaci (Gennadius) is a major pest in soybean, causing both direct feeding damage and acting as a vector for several plant viruses. The emergence of resistant B. tabaci biotypes to synthetic insecticides underscores the need for effective and sustainable alternatives. This study evaluated the efficacy of an indigenous isolate of the entomopathogenic fungus (EPF) Aschersonia aleyrodis (TMP-Dc3) for managing B. tabaci populations under laboratory and field conditions between February and October 2024. Treatments included varying conidial concentrations of A. aleyrodis (10 5 , 10 6 , 10 7 , and 10 8 conidia ml −1 ) and a synthetic insecticide (thiamethoxam) as a chemical control. The 10 7 conidia ml −1 treatment significantly suppressed B. tabaci populations in the field compared to other fungal densities and thiamethoxam. Notably, B. tabaci densities were higher in the thiamethoxam treatment, likely due to reduction in natural enemy abundance. Although thiamethoxam-treated plants produced slightly higher seed yields (14.26 g plant −1 ), plants treated with 10 7 conidia ml −1 of A. aleyrodis achieved a comparable yield (14.03 g plant −1 ). A significant negative correlation was observed between the number of empty pods and total seed weight (r = –0.697), while a positive correlation existed between whitefly populations at 56 days after planting and empty pods (r = 0.476). The TMP-Dc3 isolate exhibited strong chitinase and protease activities, highlighting its potential as a promising biopesticide and sustainable alternative to chemical insecticides for managing B. tabaci in soybeans crops.