D3457: Determining the population genetic structure and reconstructing invasion routes of wheat midge (Sitodiplosis mosellana) on the Canadian prairies

Population genomics can be an important tool to help identify patterns of movement and potential routes of invasion of agricultural pests. Identifying potential corridors of movement and population interconnections can help develop strategies to prevent further invasions or movement of these pests. In recent years, significant damage by wheat midge, Sitodiplosis mosellana (Diptera:Cecidomyiidae), a pest of wheat (Triticum aestivum), has been reported across the Northern Great Plains. Long-range dispersal events through wind or anthropogenic activities may have contributed to the current wheat midge distribution on the Prairies. However, understanding the movement of the wheat midge is difficult as several different processes may dictate their movement (e.g., short-range, stepwise, wind-mediated). In this study, we will reconstruct the route(s) of invasion of wheat midge on the Prairies and determine the origin of wheat midge in North America by assessing genome-wide population structure using a restriction site-associated DNA sequencing (RADSeq) approach. In addition, we will compare wheat midge populations to identify possible signatures of selection between invaded (North America) and native (Europe) regions, and areas of recently introduced (the Peace Region of Alberta) and established (Central Alberta) populations. Understanding how diverse wheat midge populations are in North America and their interconnectedness may contribute to the management of this pest species using midge tolerant wheat and insecticides as both can create high levels of selection pressure on midge populations.