Developing genetic control methods for the silverleaf whitefly

烟粉虱是一种由多个生物型/隐种组成的物种复合体。它有500多种寄主植物，成年苍蝇取食会对这些植物造成损害，但它们也会传播一系列植物病毒。对烟粉虱的控制主要是通过喷洒杀虫剂，但由于害虫产生抗药性和化学作用模式或停止使用，喷洒杀虫剂的效果可能有限。该项目将寻求为防治该害虫的新管理策略开发基因工具。目前的基因控制方法包括开发具有自我限制特性的转基因菌株。例如，基因工程性别鉴定允许产生仅限雄性的种群，这些种群在野外释放后将与野生种群交配，不产生雌性成虫后代，从而减少害虫数量。这种方法依赖于交配，因此具有高度的物种特异性，对生态的影响较小。一种转基因的登革热蚊子自我限制品系埃及伊蚊已经被成功地控制了这种蚊子的野生种群，类似的果蝇和鳞翅目品系正在接近田间试验测试。随着在双翅目和鳞翅目开发的技术，我们正在寻求将类似的方法应用于烟粉虱(半翅目)的管理。与烟粉虱合作，学生将开发转换方法并测试构造组件。该项目将需要分子生物学和生物信息学的研究，以识别、表征和克隆对设计新的遗传害虫管理特征感兴趣的粉虱调控序列。在项目结束时，我们建议建立遗传工具箱和方法，使开发控制该害虫和其他半翅目昆虫的新遗传方法成为可能。

The silverleaf whitefly, Bemisia tabaci, is a species complex comprising several biotypes/cryptic species. It has over 500 host plants, to which damage is caused by the adult flies feeding, but they also vector a range of plant viruses. Control of the whitefly is principally by insecticide spraying, which can be of limited effectiveness as the pest develops resistance, and chemical modes-of-action or withdrawn from use. This project will seek to develop genetic tools for new management strategies against this pest. Current genetic control approaches involve development of transgenic strains showing a self-limiting trait. For instance, engineered genetic sexing allows the production of male-only cohorts, which after release in the field will mate with wild counterparts, producing no female adult progeny and thereby reducing the pest population. This approach relies on mating, so is therefore highly species-specific with a low ecological impact. A transgenic self-limiting strain of the dengue mosquito, Aedes aegypti, has been used to successfully control wild populations of the mosquito, and similar fruit fly and lepidopteran strains are nearing field trial testing. With the technology developed in Diptera and Lepidoptera, we are seeking to apply a similar approach to management of whitefly (a hemipteran). Working with Bemisia tabaci, the student will develop transformation methods and test construct components. The project will require investigation by molecular biology and bioinformatics to identify, characterize and clone whitefly regulatory sequences of interest for engineering new genetic pest management traits. At project end, we propose to have established the genetic toolkit and methods that will enable the development of new genetic methods of controlling this pest, and other Hemiptera.