Impact of camptothecin exposures on the development and larval midgut metabolomic profiles of Spodoptera frugiperda

Spodoptera frugiperda is an economic agricultural pest that has invaded many countries around the world and caused huge losses in grain production. Camptothecin (CPT) is one of the botanical compounds with insecticidal activity and has the potential for pest control. However, the effects of CPT on development and metabolism of S. frugiperda remain unknown. In this study, we have investigated the adverse effects of 1.0 and 5.0 mg/kg CPT exposures on the growth and development of S. frugiperda. Our results found that 1.0 and 5.0 mg/kg CPT treatments altered the parameters of the life cycle, including inducing larval mortality, altering the weight of larvae, pupae, and adults, the larval duration, and decreasing the pupation rate and emergence rate. In addition, comparative metabolomics analysis was performed in the larval midgut of S. frugiperda to explore the toxicity mechanism of CPT. A total of 261 and 348 differential metabolites were identified in the groups with 1.0 and 5.0 mg/kg CPT treatments, respectively. Further analysis found that pantothenate and CoA biosynthesis, sulfur relay system, selenocompound metabolism, and fatty acid biosynthesis pathways were significantly altered by 5.0 mg/kg CPT exposure. Our results provided new insight into the toxicological mechanisms of CPT against S. frugiperda and laid the foundation for the field application of CPT in pest control.