Sublethal effect of emamectin benzoate on the development of fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith)

Spodoptera frugiperda (J.E. Smith) is a serious, polyphagous pest threatening maize cultivation worldwide due to its wide host range and strong migratory capacity. It is important to study the sublethal effects of commonly recommended pesticides like Emamectin benzoate (EMB), for effective management and to prevent pesticide resistance development. This study evaluated the effects of sublethal doses (LC₁₀ and LC₃₀) of EMB on the developmental parameters of S. frugiperda. Larval development was prolonged by 3 and 4.66 days at LC₁₀ and LC₃₀, respectively, with a significant increase in prepupal duration. Sublethal EMB doses reduced pupation by 29.3% (LC₁₀) and 50% (LC₃₀) and prolonged pupal duration in both sexes. A significant reduction in pupal weight of both male and female were observed upon treatment. These findings support in the careful use of pesticides, within IPM strategies to control S. frugiperda and delay resistance development.