叶螨（亦称红蜘蛛）是属于节肢动物门蛛形纲的极微小动物，是当今世界农林作物上的关键性害虫。因其体长微小（在1毫米以下），利用RNAi技术防治农业害螨的研究甚少。解毒代谢基因家族是昆虫体内参与代谢植物次生物质和各类杀虫剂的主要解毒酶系。本项目将叶螨解毒代谢基因家族作为害螨控制的靶标，应用叶螨全基因组序列数据库，克隆及鉴定叶螨的三大解毒代谢酶系（P450s、GSTs和CCEs）基因；建立大规模筛选RNAi 靶标基因研究平台，获取叶螨三大解毒酶系中具高效致死效应的dsRNA 分子。通过从生理、分子及细胞等不同层次水平研究，以明确dsRNA 控制害螨的效果；通过不同类型杀螨剂敏感性测定实验，基于RNAi探讨解毒代谢基因与杀虫剂代谢的关系。研究结果将对发展新的害螨防治策略，深入理解叶螨的环境适应性及三大解毒酶系与其抗性相关机制具重要意义。也为其它农业领域的害虫防治提供有益的借鉴。

Spider mites， also known as red spiders, are key insect pests of agricultural and forest crops worldwide. They are very small organisms which are members of the Phylum Arthropoda and Group Arachnida. The study on RNAi-based pest control of agricultural mites is very few，because of their tiny body length below 1mm. The gene families of detoxification metabolism are major detoxication enzyme systems that are involving in metabolizing plant secondary substances and diverse insecticides in insect body. In the study, metabolic detoxification gene families of Tetranychus urticae are firstly used as the target for controlling spider mites. The target genes of three detoxifcation enzyme systems （P450s、GSTs and CCEs）will be cloned and characterized, based on analyzing complete genome sequence database of T. urticae. The research platform for large-scale screening of RNAi target genes will be constructed to select highly lethal dsRNA molecules suppressing target genes of three detoxifcation enzyme systems. RNA interference bioassays will be carried out from physiological, molecular and cellular levels, in order to confirm the damage effects of dsRNA molecules on spider mites. RNAi to silence each of detoxification gene followed by different types of acaricide bioassays will be performed to explore the relationship between expression response and roles of detoxification genes of T. urticae to insecticide exposures. The results will play an important role in further understanding spider mites’ environmental adaptability and pesticide resistant related mechanism of three detoxification enzymatic systems. The study will be useful for developing new pest control strategy and also provide a good example for management of other agricultural insects.