Abstract: 【Aim】 To reveal the gut microbial community structure and diversity in adults of the brown planthopper (BPH), Nilaparvata lugens. 【Methods】 The total gut DNA was extracted from the adult BPH. The V3-V4 region of the bacterial 16S rRNA gene and the fungal ITS2 fragments were sequenced by Illumina MiSeq (PE300), and then the number of operational taxonomic units (OTUs), species composition, abundance and alpha diversity of gut microbes were analyzed. The high-throughput sequencing data of four randomly selected gut microbes annotated were verified by qPCR. 【Results】 A total of 32 395 valid tags and 235 OTUs were obtained for gut bacteria of adult BPH, while the numbers of valid tags and OTUs for gut fungi were 24 986 and 128, respectively. The total OTUs of gut bacteria were annotated into 7 phyla, 15 classes, 26 orders, 45 families and 73 genera, while the fungal OTUs were annotated into 3 phyla, 9 classes, 12 orders, 15 families and 18 genera. At the phylum levels, the dominant gut bacteria were Proteobacteria, Bacteroidetes and Firmicutes, while the dominant gut fungi with the highest abundance belonged to Ascomycota. Acinetobacter, one indeterminate genus in Porphyromonadaceae and one indeterminate genus in Lachnospiraceae were dominated at the genus level in the bacterial communities, with the abundance of 36.37%, 17.22% and 15.01%, respectively. Fungi belonging to an indeterminate genus in Sordariomycetes were the most dominant, accounting for 95.77%. The alpha diversity analysis revealed that the number of observed species, Chao1 index, Shannon index and Simpson index were 235, 262.64, 3.90 and 0.62 for gut bacteria, and 128, 165.40, 0.91 and 0.75 for gut fungi, respectively. The qPCR results of four gut microbes confirmed that the highthroughput sequencing data had a high validity. 【Conclusion】 The results indicate that the bacteria and fungi are diverse in the gut of adult BPH. The results of this study not only lay the foundation for the further studies on the environmental adaption mechanisms of BPH from a microbial standpoint, but also facilitate the studies on the development of new technology for the biocontrol of BPH.

Key words: Nilaparvata lugens, gut microbiota, 16S rRNA, ITS2, high-throughput sequencing, bacteria, fungi, species diversity