Developing genetic control methods for the silverleaf whitefly

烟粉虱（Bemisia tabaci）是一个由多个生物型/隐种组成的物种复合体。它有超过500种寄主植物，成年苍蝇进食会造成损害，但它们也携带一系列植物病毒。粉虱的防治主要是通过喷洒杀虫剂，但由于害虫产生抗药性，喷洒杀虫剂的效果有限，而且化学作用方式或停止使用。该项目将寻求开发遗传工具，以制定防治这种害虫的新管理战略。目前的遗传控制方法涉及开发显示自限性性状的转基因菌株。例如，基因工程性别鉴定允许产生仅雄性的群体，这些群体在田间释放后将与野生对应物交配，不产生雌性成年后代，从而减少害虫种群。这种方法依赖于交配，因此具有高度的物种特异性，对生态的影响很小。一种转基因的自限性登革热蚊子-埃及伊蚊-已被用于成功地控制野生蚊子种群，类似的果蝇和鳞翅目蚊子品系也即将进行实地试验。随着双翅目和鳞翅目的技术发展，我们正在寻求将类似的方法应用于粉虱（半翅目）的管理。与烟粉虱合作，学生将开发转化方法和测试构建组件。该项目将需要通过分子生物学和生物信息学进行调查，以确定、表征和克隆感兴趣的粉虱调节序列，用于设计新的遗传害虫管理性状。在项目结束时，我们建议建立遗传工具包和方法，这将使新的遗传方法的发展控制这种害虫，和其他半翅目。

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spraying, which can be of limited effectiveness as the pest develops resistance, and chemical modes-of-action or withdrawn from use.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.