Compatibility of the insect pathogenic fungus <i>Beauveria bassiana</i> with neem against sweetpotato whitefly, <i>Bemisia tabaci</i>, on eggplant

Abstract

Abstract A study on the compatibility of the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuillemin (Ascomycota: Hypocreales) with neem was conducted against sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), on eggplant. Initially, three concentrations of B. bassiana (10 6 , 10 7 , and 10 8 conidia ml −1 ) and three concentrations of neem (0.25, 0.5, and 1.0%) were used as individual treatments against B. tabaci . The highest concentration of B. bassiana yielded the highest B. tabaci egg (25.2%) and nymph mortalities (73.0%), but this was not significantly different from the mortalities caused by the 10 7 conidia ml −1 suspension. Similarly, the highest concentration of neem yielded the highest egg (27.3%) and nymph mortalities (75.5%), which was also not significantly different from the 0.5% suspension. Therefore, 0.5% neem was used along with 10 7 B. bassiana conidia ml −1 suspension as an integrated pest management program against B. tabaci . The combination of B. bassiana and neem yielded the highest B. tabaci egg (29.5%) and nymph mortalities (97.2%), and the lowest LT 50 (2.08 day) value. Moreover, an integrated combination of B. bassiana with neem caused 27.6 and 20.5% more nymphal mortality than individual treatments of B. bassiana and neem, respectively, 7 days post‐application. Thus, a combined application of an entomopathogenic fungus and a botanical insecticide may benefit from both, and it has proven effective for the control of B. tabaci on eggplant.