【目的】 肠道微生物在害虫抗性发展中发挥着重要作用，斜纹夜蛾Spodoptera litura是全球范围内的广食性害虫，其抗性问题已成为世界性难题。本研究旨在探究对溴虫氟苯双酰胺敏感和抗性斜纹夜蛾种群的肠道微生物的多样性差异，分析肠道微生物与宿主抗药性的关系。【方法】 选取中等抗性水平与敏感水平的斜纹夜蛾提肠道微生物DNA样本，利用高通量测序技术进行16S V3-V4区域的扩增子测序，基于97%相似度优化OTUs（Operational taxonomic units），开展物种丰度、肠道微生物组成结构、α多样性和β多样性分析等。【结果】 微生物组测序共获得1 208 279条序列，经优化聚类为529个OTUs，共22个门44个纲84个目138个科207个属。从属水平上看，敏感种群有62个特有菌属，抗性种群有50个特有菌属，两品系共同拥有菌属95个。在肠道菌群组成方面两品系有显著差异（P<0.05），抗性种群主要以丹毒丝菌属Erysipelatoclostridium为主，敏感种群以肠球菌属Enterococcus为主，相对丰度分别为57.24%和47.71%。多样性分析表明，抗性种群斜纹夜蛾的肠道微生物群落物种丰度最多，敏感种群斜纹夜蛾的物种丰富度和均匀度则要更高。【结论】 田间大量施药影响斜纹夜蛾肠道菌群，使得肠道菌群复杂多样。两品系的微生物群落构成明显不同，抗性种群斜纹夜蛾的菌群组成更为复杂，敏感种群斜纹夜蛾的菌群组成更稳定。本研究为开发新型农药提供了新思路，并为进一步揭示斜纹夜蛾抗性机理奠定了基础。

 [Aim]  Gut microbes play an important role in the development of pest resistance. Spodoptera litura is a widespread polyphagous pest species that is becoming increasingly resistant to pesticides. To determine the relationship between gut microbes and host resistance, we compared gut microbial diversity between bromoflumizamide-susceptible and bromoflumizamide-resistant populations of S. litura. [Methods]  DNA samples of gut microorganisms were taken from S. litura with intermediate levels of bromoflumizamide resistance and susceptibility. Amplicon sequencing of the 16S V3-V4 region was carried out using high-throughput sequencing technology to optimize the OTUs based on 97% similarity and determine microbe species abundance, gut microorganism composition and structure, α diversity, and β diversity. [Results]  Total microbiome sequencing yielded 1 208 279 sequences which were optimally clustered into 529 OTUs containing 22 phyla, 44 classes, 84 orders, 138 families, and 207 genera. At the genus level, there were 62 endemic genera in the bromoflumizamide-susceptible population and 50 endemic genera in the bromoflumizamide-resistant population. The two populations shared 95 genera. There were significant differences in the composition of the intestinal flora between the two strains (P<0.05). Erysipelatoclostridium dominated the microbiome of the bromoflumizamide-resistant population, whereas Enterococcus was the dominant microbiome in the bromoflumizamide-susceptible population, with relative abundances of 57.24% and 47.71%, respectively. Diversity analysis showed that the intestinal microbial community of the bromoflumizamide-resistant population of S. litura had the highest species abundance. In contrast, the bromoflumizamide- susceptible S. litura population had a higher species richness and consistency. [Conclusion]  There was a significant difference in the microbial community composition between the bromoflumizamide-susceptible and bromoflumizamide-resistant populations. The bromoflumizamide-resistent population of S. litura exhibited a more complex gut microbome composition, while the bromoflumizamide-susceptible S. litura population exhibited a more stable flora composition. In this paper, we explored the relationship between insect resistance and gut microorganism diversity. Our findings provide a new perspective for the development of novel pesticides and lay a foundation for further research into the mechanisms of resistance in S. litura.