The work in this proposal is designed to screen for insecticide resistance in UK populations of codling moth, and to identify the genomic location of insecticide resistances to several insecticides in the wider European population of codling moth. The identification of sources of resistance is crucial in order to understand the process of geneflow in the wider codling moth population and the role of human-aided dispersal in spreading resistance.
Codling moth is a particularly good model in which to study resistance to a wide range of insecticides, due the the long history of chemical control, the development of multiple resistances to older pesticides as well as the whole range of biological controls available (entomopathogens and granulovirus). This wide range of controls means that many research groups focus on codling moth across the world, and the linking up of these research communities through resources that can be shared (such as DNA sequence data, inbred lines etc) will foster global cooperation into research and control of this deleterious global pest.
In this project we will collect moths from multiple sources in the UK and populations in the EU known to carry resistance to important classes of pesticides. These will then be selected on in the laboratory to create lines expressing multiple resistances. We will then use a technique known as linkage mapping to build a map of the genome, which will then allow us to identify the area of the genome that harbour insecticide resistance genes. We will use a new technique that utilises new DNA sequencing technologies to achieve this objective. We can then use genetic markers in these areas to identify the geographic source of resistance.
This work will inform policy makers whether resistance is already present in UK populations, and if it is the genetic basis of that resistance. This will allow future resistance screens to take place. Furthermore, it will provide useful information as to the genetic basis of resistance in codling moth, which through comparisons with other lepidopteran species can then be narrowed to the candidate gene level.
It may also allow resistance in other lepidopteran pests to be identified more quickly, as arthropod genomes appear to be structurally stable over long periods of evolutionary time, allowing genes from one species to be identified in other species relatively quickly.
Project Leader: Dr Richard Harrison
Co-workers: Dr Michelle Fountain
Team members: Judit Linka