Gut Microbiomes of Two Bamboo Locusts Reveal Divergent Metabolic Potentials

The yellow-spined bamboo locust (Ceracris kiangsu) and the green-spined bamboo locust (Ceracris nigricornis) are two common bamboo-feeding forestry pests in China. C. kiangsu has stronger migratory capacity and causes greater damage, yet comparative studies of their gut microbiota are lacking. Here, we profiled the gut microbial communities of female C. kiangsu from six geographic populations using 16S rRNA gene amplicon sequencing (Illumina MiSeq) and compared these data with publicly available gut microbiome datasets of female C. nigricornis from NCBI. At the phylum level, the gut microbiota of both species was dominated by Firmicutes and Proteobacteria. At the genus level, dominant taxa included Klebsiella and Achromobacter. Despite these similarities, the two species differed significantly in microbial diversity. Alpha-diversity indices showed highly significant differences in richness and diversity (p < 0.01), and beta-diversity analyses (PCoA) revealed clear separation of community structure between species (PERMANOVA, p < 0.001). Functional prediction using PICRUSt2 indicated that, at KEGG Level 2, pathways related to carbohydrate and lipid metabolism were significantly enriched in C. kiangsu compared with C. nigricornis. At KEGG Level 3, C. kiangsu also showed higher predicted abundances of starch and sucrose metabolism, glycolysis/gluconeogenesis, the pentose phosphate pathway, and pyruvate metabolism. Collectively, these results reveal distinct gut microbial communities and predicted functional profiles between the two species. The enrichment of predicted carbohydrate- and lipid-related pathways in C. kiangsu generates a testable hypothesis that its gut microbiota may be associated with host energy metabolism, but direct links to flight performance or ecological fitness require further experimental validation.