Developing genetic control methods for the silverleaf whitefly

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spraying, which can be of limited effectiveness as the pest develops resistance, and chemical modes-of-action or withdrawn from use.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