Community structure and diversity of culturable bacteria in the feces of potato tuber moth（Phthorimaea operculella Zeller）larvae

【Objective】To reveal the community structure and diversity of culturable bacteria in the feces of potato tuber moth（Phthorimaea operculella Zeller）larvae，which provide scientific basis for a deeper understanding of the diversity and function of its gut microbiota.【Method】Fresh and dry feces of potato tuber moth larvae were used as research objects. The bacterial suspension of potato tuber moth larvae feces was isolated，cultured，and purified on LB medium using culture analysis method. Various species were classified and identified based on the results of 16S rDNA bidirectional sequencing，combined with the culture characteristics and morphological features of the strain. Contigexpress software was used for sequence assembly and proofreading of the sequencing results，and the results were submitted to the NCBI（GenBank）database for alignment. A phylogenetic tree was constructed using MEGA7.0 software. The diversity of the culturable bacterial community in fresh and dry feces was comprehensively assessed using Margalef richness index，Simpson dominance index，Shannon Wiener diversity index，and Pielou evenness index.【Result】There were 3 phyla，9 families， 9 genera and 14 species of culturable bacteria in the fresh feces of potato tuber moth，with Enterococcus mundtii being the dominant species，with 71.25% relative abundance. In the dry feces，there were 3 phyla，6 families，7 genera，and 11 species of culturable bacteria，with Staphylococcus succinus and Staphylococcus saprophyticus being the dominant species，relative abundances were 29.45% and 18.70% respectively. The bacterial community species diversity indexes in fresh and dry feces were 1.23 and 2.02 respectively，and the evenness indexes were 0.47 and 0.84 respectively. The results indicated that the diversity of culturable bacteria in dry feces was higher than that in fresh feces，and the bacterial community had a more even species composition，while the culturable bacterial community in fresh feces was relatively concentrated in species composition.【Conclusion】The bacterial species in potato tuber moth feces are abundant， and there are obvious differences in the composition of culturable bacteria，dominant species，richness，and evenness between fresh and dry feces，especially the culturable bacterial community in fresh feces is concentrated and show higher species richness，while the dry feces show a more even bacterial community composition.