Ontogenetic Analysis of Chelonus formosanus and Diversity of Its Internal Microbiota

Chelonus formosanus is a parasitic wasp capable of parasitizing various Noctuidae pests, including the highly invasive Spodoptera frugiperda, and it demonstrates strong pest control potential. Both egg and larval stages primarily occur within the host organism, and the total developmental time from egg to adult is approximately 19.62 days. To investigate the microbial communities at different stages, we performed 16S rDNA sequencing (V1–V9 region) using PacBio sequencing and identified 404 bacterial species belonging to 61 classes, 116 orders, 182 families, and 308 genera across larval, pupal, female, and male adult stages. Bacterial diversity and richness varied across the stages, with Enterobacter and Enterococcus dominating in larvae and pupae and Pseudomonas emerging as dominant in female adults. In contrast, male adults predominantly resided with Ralstonia and Achromobacter. The predicted functions of bacteria within C. formosanus at different developmental stages are predominantly marked by the high abundance of metabolic pathways. This study provides a comprehensive understanding of the morphology of C. formosanus and contributes to the practical control of host pests. Additionally, our findings preliminarily characterized the microbial community of various developmental stages, laying the groundwork for its functional study.