Sublethal Effects of the Microbial-Derived Insecticide Spinetoram on the Growth and Fecundity of the Fall Armyworm (Lepidoptera: Noctuidae)

The fall armyworm, Spodoptera frugiperda (J. E. Smith), is one of the most important pests in tropical and subtropical regions of American. S. frugiperda was first detected in Southern China in January 2019, and then subsequently invaded in 26 provinces. Spinetoram widely used for pest management is recommended for S. frugiperda control. The sublethal effects of spinetoram on S. frugiperda were investigated in the present study. The toxicity of spinetoram against S. frugiperda larvae was determined after one oral dose of spinetoram at sublethal concentration. The results showed that spinetoram LC10 and LC30 were 0.011 and 0.044 mg/liter for the larvae, respectively. Spinetoram at sublethal concentration significantly increased developmental time but reduced larval body weight. In addition, spinetoram had a post-exposure effect on pupal weight, but not on pupal duration, pupation rate, emergence rate, eggs number, or adults longevity. In conclusion, the sublethal effects of spinetoram could negatively affect the growth and development of S. frugiperda that have important implications for pest management.