【目的】研究并比较冬虫夏草Ophiocordyceps sinensis (Berk.) Sung et al.寄主白马蝠蛾Hepialus baimaensis Liang和云南蝠蛾Hepialus yunnanensis Yang, Li et Shen体内微生物群落组成及其功能差异，初步分析蝠蛾体内微生物群落对冬虫夏草菌侵染蝠蛾的影响。【方法】 对白马蝠蛾（Hb）和云南蝠蛾（Hy）4-5龄期幼虫内微生物进行Ion S5^TMXL高通量测序，并利用生物信息学软件对细菌和真菌群落分别进行群落组成、LefSe（LDA Effect Size）、功能预测分析和比较分析。【结果】 Hb组细菌共鉴定17门145属；Hy组细菌共鉴定23门202属。Hb组细菌中肉杆菌属Carnobacterium相对丰度占比最高，为95.55%；Hy组细菌中沃尔巴克氏体Wolbachia占主要比例（85.28%）。Hb组真菌共鉴定4门114属；Hy组真菌共鉴定5门113属。Hb组真菌中假裸囊菌属Pseudogymnoascus为最优势属（46.23%），Hy组真菌中菌刺孢属Mycocentrospora为最优势属（37.87%）。LefSe分析Hb组中有5个细菌分类单元和12个真菌分类单元与Hy组具有显著差异，而Hy组中有7个细菌分类单元和9个真菌分类单元与Hb组具有显著差异。两组样本细菌群落进行COG功能预测，Hb组更偏向氨基酸转运与代谢功能，而Hy组更偏向翻译、线粒体的结构与发生功能。两组样本细菌群落进行KEGG功能预测，Hb组中DNA解旋酶、ATP结合区和ABC转运蛋白丰度较高，Hy组中辅酶Q还原酶、推定转座酶和核糖体丰度较高。真菌群落FUNGuild分析，Hb组中46.26%的真菌属于动物病原菌-土壤腐生真菌类别；而Hy组占比最高真菌类别为植物病原菌（38.31%）。两组真菌样本进行KEGG和MetaCyc pathway功能预测，两组样本中真菌功能丰度较高的类别均与基础代谢或生理功能相关。【结论】 白马蝠蛾和云南蝠蛾4-5龄期幼虫体内细菌和真菌组成及其功能存在一定差异，而与其它寄主蝠蛾相比，白马蝠蛾4-5龄期幼虫内细菌和真菌组成存在相同的类群。本研究发现，白马蝠蛾4-5龄期幼虫内优势菌属肉杆菌属和假裸囊菌属很可能在冬虫夏草寄主蝠蛾生长发育、冬虫夏草侵染等过程中发挥重要作用。

[Objectives]  To compare the microbial community composition and function of Hepialus baimaensis Liang and H. yunnanensis Yang, Li et Shen, and to investigate the influence of the microbial community on the infection of H. baimaensis by Ophiocordyceps sinensis (Berk.) Sung et al.. [Methods]  The microbial 16S rRNA and internal transcribed space (ITS) of 4th and 5th instar larvae of H. baimaensis and H. yunnanensis were sequencing using the Ion S5^TMXL high-throughput sequencing method. The community composition of these species, LefSe (LDA effect size), predicted community function and comparative analysis of bacteria and fungi, were carried out using bioinformatics analysis software. [Results]  Seventeen phyla and 145 genera of bacteria were identified in H. baimaensis, and 23 phyla and 202 genera in H. yunnanensis. In H. baimaensis, 95.55% of bacteria species belonged to the dominant genera Carnobacterium, whereas Wolbachia was the dominant genera (85.28%) in H. yunnanensis. Four phyla and 114 fungal genera were identified in H. baimaensis, and 5 phyla and 113 genera in H. yunnanensis. Pseudogymnoascus was dominant fungal genera (46.23%) in H. baimaensis, whereas Mycocentrospora was the dominant genera (37.87%) in H. yunnanensis. LefSe analysis indicates that the 5 bacterial taxa and 12 fungal taxa found in H. baimaensis were significantly different to those found in H. yunnanensis. The 7 bacterial taxa and 9 fungal taxa in H. yunnanensis were also significantly different to those in H. baimaensis . COG analysis of the bacterial communities indicates that most bacteria are involved in amino acid transport and metabolism in H. baimaensis, whereas most are involved in translation, ribosomal structure and biogenesis in H. yunnanensis. Bacterial KEGG function predicted that the most common microbial functions were associated with DNA helicase, the ATP-binding cassette and ABC transporters in H. baimaensis, and with NADH: Ubiquinone reductase (H (+)-translocating), putative transposase and ribosome in H. yunnanensis. A FUNGuild analysis of fungal community indicates that 46.26% of all fungi originated from animal pathogen-soil saprotrophs in H. baimaensis. However, in H. yunnanensis, 38.31% of fungi originated from plant pathogens. KEGG and MetaCyc pathway function prediction indicates that the majority of fungi are related to basic metabolic, or physiological, functions. [Conclusion] The bacterial and fungal communities of 4th and 5th instar H. baimaensis and H. yunnanensis larvae were entirely different and there were also some differences in the functions of these communities between species. The bacterial and fungal communities of H. baimaensis larvae were the same as those of other hosts of O. sinensis, whereas the corresponding communities in H. yunnanensis were not. Carnobacterium and Pseudogymnoascus were, respectively, the dominant bacterial and fungal genera in H. baimaensis, and could play important roles in both larval growth and development, and in infection by O. sinensis.