【目的】 Asaia属醋酸菌已被证明与双翅目、膜翅目、半翅目和鳞翅目的多种昆虫存在着重要的共生关系。本研究检测斜纹夜蛾Prodenia litura (Fabricius)、粘虫Mythimna separata Walker、小地老虎Agrotis ypsilon Rottemberg和甘蓝夜蛾 Mamestra brassicae Linnaeus 体内Asaia的感染情况，并研究了Asaia的传递效率。【方法】 基于16 s rDNA特异序列检测，分析Asaia在4种鳞翅目害虫中的感染情况。通过建立感染Asaia的斜纹夜蛾品系，检测其垂直传递效率。【结果】 Asaia在斜纹夜蛾、粘虫、小地老虎和甘蓝夜蛾田间种群中均有感染，其感染率分别为45.8%、66.7%、47.2%和31.0%。系统发育分析表明，Asaia 16S rDNA序列可分为3种序列型ST1、ST2和ST3，其中4种昆虫中均含有ST1序列型。父母亲本均感染Asaia的斜纹夜蛾后代，Asaia感染率达到91.7%。【结论】 Asaia在鳞翅目害虫中存在较高的感染率，在昆虫物种间可能存在水平传递并且在种内可进行垂直传递。

[Objectives]  Bacteria of the genus Asaia can symbiotically colonize insects of phylogenetically distant genera and orders, e.g. Diptera, Hymenoptera, Hemiptera and Lepidoptera. Our aim in this study was to investigate the prevalence of Asaia infection in four Lepidopteran species; Prodenia litura (Fabricius), Mythimna separata Walker, Agrotis ypsilon Rottemberg and Mamestra brassicae Linnaeus, and to analyze its mode of transmission within and between species. [Methods]  Asaia infection rates were investigated using the polymerase chain reaction (PCR) with primers targeting the Asaia 16S rDNA sequence. An Asaia-infected P. litura strain was established to study the vertical transmission of Asaia. [Results]  We found that P. litura, M. separata, A. ypsilon and M. brassicae, were all infected with Asaia bacteria with infection rates of 45.8%, 66.7%, 47.2% and 31.0%, respectively. Phylogenetic analysis based on the Asaia 16S rDNA sequences revealed three sequence types: ST1, ST2 and ST3. All four species were infected with the ST1 type indicating a high possibility of horizontal transmission of Asaia among species. Our results also demonstrate the vertical transmission of Asaia from infected P. litura to their offspring. [Conclusion]  Asaia has a high prevalence in the four Lepidopteran species examined and can be both horizontally, and vertically, transmitted.