Composition and Diversity Characteristics of Gut Microbiota during the Development of Telchinia issoria (Lepidoptera: Nymphalidae).

Ramie (Boehmeria nivea) was a traditional economic crop of high commercial value, whose cultivation was threatened by the leaf-feeding pest Telchinia issoria. This study investigated how the gut microbiota of T. issoria shifted across its larval, pupal, and adult stages using 16S rRNA amplicon sequencing. We found that Pseudomonadota and Bacillota dominated across all stages, with stage-specific enrichments of key genera: Burkholderia-Caballeronia-Paraburkholderia in early larvae, Acinetobacter and Culicoidibacter in mid-instars, Serratia in late larvae, Enterococcus in pupae, and Pseudomonas in adults. Alpha diversity exhibited a U-shaped pattern during larval development, decreasing initially before rising again, with the lowest overall diversity observed in the pupal stage. Beta diversity confirmed distinct community structures in pupae and adults. Functionally, as predicted by PICRUSt2 based on 16S rRNA gene sequencing data, carbohydrate metabolism was enriched in pupae, whereas pathways associated with amino acid, cofactor, and vitamin metabolism were significantly decreased relative to other developmental stages. Correlation analysis suggested that elevated temperature may contribute to the decreased diversity observed in this study, which warranted further verification under controlled temperature gradients. This work establishes a foundational understanding of stage-specific microbial symbiosis in T. issoria and offers insights for future research into lepidopteran gut microbial ecology and potential biocontrol applications.