【目的】冬虫夏草是由冬虫夏草菌Ophiocordyceps sinensis侵染蝙蝠蛾幼虫形成的一种独特而有价值的虫菌复合体。人工栽培冬虫夏草时，将蝙蝠蛾幼虫血淋巴中的冬虫夏草菌芽生孢子诱导成为菌丝，是被感染幼虫僵化的先决条件。为探讨冬虫夏草菌和昆虫激素对小金蝠蛾Thitarodes xiaojinensis幼虫僵化、血淋巴和肠道微生物以及血淋巴化学物质的影响。【方法】 将冬虫夏草菌芽生孢子（KD菌株）、芽生孢子和蜕皮激素（KD+20E）、芽生孢子和保幼激素（甲氧普林）（KD+M）、20E和M分别注射小金蝠蛾6龄幼虫，以注射无菌PBS、35% DMSO以及未注射任何物质的幼虫作为对照，测定幼虫的僵化率、血淋巴和肠道可培养微生物，以及血淋巴的关键物质（法尼醇、酪醇、麦角甾醇、蜕皮激素、保幼激素、葡萄糖、一氧化氮、海藻糖、N-乙酰葡糖胺）的含量。【结果】 注射KD+M 120 d后小金蝠蛾幼虫的僵虫率显著提高。注射KD+20E的幼虫血淋巴中分离到更多细菌种类，而注射KD+M幼虫血淋巴中分离得到更多真菌种类。Pseudomonas mucidolens、Serratia proteamaculans和Tsukammurella standjordii细菌出现于所有处理和注射PBS的幼虫血淋巴中（除了T. standjordii未出现于注射甲氧普林的幼虫血淋巴中）；高频率出现的真菌种类为Cladosporium sp.、Isaria farinosa和Talaromyces sp.，这些菌株均未出现在未注射幼虫的血淋巴中。7种细菌（Carnobacterium maltaromaticum、Flavobacterium frigidimaris、Microbacterium oxydans、P. mucidolens、Rahnella aquatilis、S. proteamaculans、T. strandjordii）和1种真菌（Apiotrichum porosum）出现于所有幼虫肠道中；C. maltaromaticum是幼虫肠道优势种；注射KD+M增加幼虫肠道真菌的可培养种类；高频率出现的真菌种类为I. farinosa和Penicillium sp.；从幼虫肠道组织中未分离到Ophiocordyceps sinensis。未注射芽生孢子、注射KD+20E的小金蝠蛾幼虫血淋巴中均未检测到N-乙酰葡萄糖胺。与对照组相比，注射芽生孢子和昆虫激素未显著改变血淋巴中法尼醇、蜕皮激素、海藻糖、一氧化氮的含量，但注射KD、KD+20E、KD+M、20E和M 45 d时可提升幼虫血淋巴的保幼激素含量。无论携菌与否，幼虫血淋巴中未检测到酪醇。【结论】 注射冬虫夏草菌芽生孢子和昆虫激素，可影响小金蝠蛾幼虫的僵化率、血淋巴和肠道微生物种类以及血淋巴内相关化学物质的含量。研究结果为有效提高冬虫夏草人工培育过程中的幼虫僵化率，理解昆虫、真菌与昆虫激素的交互作用提供参考。

[Objectives]  To investigate the effect of the fungus Ophiocordyceps sinensis (a unique and valuable parasitic complex formed by the infection and subsequent mummification of Thitarodes larvae by O. sinensis) and insect hormones on the blastospore-hypha conversion in Thitarodes larvae (the formation of hyphae from the blastospores of O. sinensis in the hemolymph of Thitarodes larvae is a prerequisite for the mummification of infected larvae). [Methods]  One of five treatments; blastospores of O. sinensis (KD strain), a mixture of blastospores and 20-hydroxyecdysone (KD+20E), a mixture of blastospores and methoprene (KD+M), 20-hydroxyecdysone (20E) or Methoprene, were injected into sixth instar T. xiaojinensis larvae and the subsequent larval mummification rate, hemolymph and intestinal microorganisms and amounts of related substances (farnesol, ergosterol, ecdysterone, juvenile hormone III, N-acetylglucosamine, glucose, trehalose, nitric oxide) in larval hemolymph were compared. [Results]  The mixture of blastospores and methoprene significantly increased the mummification rate of larvae after 120 days. More bacterial species were isolated from larval hemolymph injected with KD+20E, whereas more fungi were isolated from larvae injected with KD+M. Three bacterial species including Pseudomonas mucidolens, Serratia proteamaculans and Tsukammurella standjordii, were detected in all treatments, except for the absence of T. standjordii in the hemolymph of larvae injected with Methoprene. Cladosporium sp., Isaria farinosa and Talaromyces sp. were the most frequently observed fungal species, none of which were found in the hemolymph of larvae that had not been injected. Seven bacterial species, including Carnobacterium maltaromaticum, Flavobacterium frigidimaris, Microbacterium oxydans, P. mucidolens, Rahnella aquatilis, S. proteamaculans and T. strandjordii, as well as one fungal species, Apiotrichum porosum were detected in the guts of all treated larvae. C. maltaromaticum was the dominant bacterial species found in larval guts. The injection of KD+M increased the culturable fungal species in larval guts. The most common fungal species were I. farinosa and Penicillium sp., whereas O. sinensis was not isolated from larval guts. Compared to the control (PBS) group, the injection of blastospores of O. sinensis and insect hormones did not significantly change the levels of farnesol, 20E, trehalose and nitric oxide, but injection of the KD, KD+20E, KD+M, 20E and M increased the amount of juvenile hormone in larval hemolymph after 45 days. N-acetylglucosamine was absent in the hemolymph of larvae that were not injected or that had been injected with KD+20E. Tyrosol was not detected in the hemolymph of larvae irrespective of the presence or absence of O. sinensis blastospores. [Conclusion]  The mummification rate, hemolymph, intestinal microorganisms and levels of related substances in the hemolymph, of T. xiaojinensis larvae were all affected by injecting them with blastospores of O. sinensis, 20-hydroxyecdysone or Methoprene. These results provide useful insights for improving the larval mummification rate during artificial cultivation of O. sinensis, and improve understanding of the interactions between insects and fungal pathogens.