Transgenerational Sublethal Effects of Chlorantraniliprole and Emamectin Benzoate on the Development and Reproduction of Spodoptera frugiperda

SIMPLE SUMMARY: This study documents the sublethal effects of emamectin benzoate and chlorantraniliprole on the growth, development, and reproduction of the fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae). FAW is an invasive agricultural pest that poses a significant threat to grain production worldwide. We analyzed the age-stage, two-sex life table to understand the impact of sublethal doses (LC(10) and LC(25)) of emamectin benzoate and chlorantraniliprole on FAW. Our findings indicate that both emamectin benzoate and chlorantraniliprole prolong the development of the FAW F(0) generation, and fecundity was reduced at increasing concentrations of the insecticide. In the F(1) generation, emamectin benzoate significantly reduced fecundity, and the LC(10) dosage shortened the preadult period without affecting the adult stage. Furthermore, chlorantraniliprole lengthened the preadult and adult stages of FAW at LC(10) and LC(25), respectively, which significantly improved fecundity. Overall, our results indicate that emamectin benzoate effectively inhibits FAW population growth at low concentrations. In contrast, chlorantraniliprole may stimulate population growth and cause a resurgence of the FAW population. ABSTRACT: Spodoptera frugiperda (J. E. Smith), commonly known as the fall armyworm (FAW), causes significant damage to many different crop species. In this study, age-stage, two-sex life table analysis was used to investigate the effects of sublethal concentrations of emamectin benzoate and chlorantraniliprole on FAW development and reproduction. In the F(0) generation, exposure to emamectin benzoate and chlorantraniliprole significantly impacted the duration of FAW, thus prolonging the development duration of each instar, but not the prepupal stage. Furthermore, the weight of FAW pupae was significantly reduced by emamectin benzoate at LC(25) and chlorantraniliprole at LC(25) in the F(0) generation. With respect to fecundity, emamectin benzoate and chlorantraniliprole significantly reduced fecundity in the F(0) generation. In the F(1) generation, emamectin benzoate at LC(10) had no significant effect on the preadult or adult stages, whereas LC(25) significantly shortened the preadult period. The preadult and adult stages of FAW exposed to chlorantraniliprole at LC(10) and LC(25) were significantly prolonged. Furthermore, emamectin benzoate had no significant effect on the pupal weight of the F(1) generation. Chlorantraniliprole had no significant effect at LC(10), but significant reduced pupal weight occurred at LC(25) in the F(1) generation. With respect to fecundity, emamectin benzoate significantly reduced fecundity in the F(1) generation. Interestingly, chlorantraniliprole significantly increased fecundity in the F(1) generation, which could promote population growth and pest resurgence. These findings have important implications for the integrated pest management of FAW and provide a reference for the more effective control of FAW.