马铃薯甲虫是国际公认的马铃薯毁灭性害虫，入侵我国新疆地区后，对我国马铃薯产业构成了严重的威胁，且其进一步扩散的风险正在加剧。肠道微生物是昆虫重要的组成部分，与宿主昆虫相互合作、协同进化。课题组前期研究表明，肠道微生物参与调控了植物的抗虫性，但目前还不知道其是否介导马铃薯甲虫的生物入侵。本项目拟以入侵我国的马铃薯甲虫为主要研究对象，利用16S rRNA扩增子测序、宏基因组测序以及传统培养法对其肠道微生物进行分离鉴定，分析比较美国原产地与入侵地新疆马铃薯甲虫肠道微生物种类和丰度的差异，测定肠道差异菌株对马铃薯植株抗虫能力和防御反应的影响，再利用荧光原位杂交技术和荧光定量PCR技术验证肠道差异菌株存在的部位和含量，从而揭示肠道微生物可能协助马铃薯甲虫在新的入侵地适应寄主植物抗性加剧生物入侵的机制，进一步阐明昆虫生物入侵机制和昆虫肠道微生物的生态学功能，为入侵生物马铃薯甲虫的综合防控提供新的策略。

Colorado potato beetle (CPB, Leptinotarsa decemlineata) is a very important destructive pest worldwide. After its invasion to Xinjiang Autonomous Region this pest has caused huge losses of potato yield together with the increasing risk of further dispersal and spreading to inland. Gut-associated microbes are treated as significant organs of insects, and interact and co-evolve with their host-insects. Our previous work showed that gut microbes played a key role in regulating plant induced defenses, but there is little information about the role of gut-associated microbes in the manipulation of invasive process of CPB. This study will investigate the gut microbes of invasive CPB using the methods of 16S rRNA sequencing, metagenome analysis and traditional bacterial isolation and identification. We will compare the differences in the diversity and abundance of gut microbes of CPB colonies between the native region United States and introduced region Xinjiang, and figure out the distinct bacterial isolates. Then the function of these different bacterial isolates in mediating the resistance and induced defenses of potato plants to insects will be determined. Fluorescence in situ hybridization will be used to observe the location of target bacterial strains, and the relative quantities of these bacteria on leaves or in insect inner organ will be examined by quantitative real time PCR. This study will test the hypothesis whether or not the gut-associated microbes play a key role in assisting CPB to adapt to the host-plant defense system to facilitate its invasion to new regions. The results will highlight the novel mechanism of CPB invasion and important ecological role of gut microbes, thus will provide a new guideline for invasive pest management.