Population dynamics and monitoring programs for midges attacking canola
Term: 3 years, beginning 2024
Status: Ongoing
Researcher(s): Meghan Vankosky, AAFC
SaskCanola Investment: $27,610
Total Project Cost: $110,4400
Funding Partners: WGRF, ACPC
Objective
1. Use a network of pheromone traps to monitor for swede midge in western Canada, to ensure early detection of a possible invasion.
2. Use a network of pheromone traps to monitor for canola flower midge, to detect changes in its population density and geographic range in western Canada.
3. Determine the seasonal population dynamics and potential for canola flower midge to impact canola yields.
Project Description
Two species of midge pose a threat to canola production in western Canada. Swede midge is invasive to eastern Canada where it has caused significant economic yield losses. Thus far, swede midge has not established in western Canada, but its geographic range is expanding westward from the northeastern United States. Swede midge could have a devastating impact on the canola and horticultural industries in western Canada. If swede midge continues to disperse westward, early detection will be key to attempting its eradication and preventing it from becoming an established pest in western Canada that requires management using insecticides or other inputs.
Canola flower midge was recently discovered and described in western Canada. It is widely distributed in western Canada and has been detected in Ontario and parts of the Northern Great Plains in the United States. Populations of canola flower midge have only been monitored on a small scale since 2019; a more comprehensive monitoring program is needed to identify regions where canola flower midge densities might result in risk to canola yields. More information is also required to understand and estimate the potential risk that canola flower midge poses to the canola industry. Canola flower midge does not appear to cause significant economic damage at its current population densities. However, due to its patchy distribution and our inability to rear the canola flower midge in the laboratory, conducting experiments to estimate its affect on canola yield has proven to be challenging.
The project also aims to build on our current knowledge to better understand the potential for canola flower midge to impact canola yields. We know from previous CARP projects (co-led by Drs. Mori and Vankosky) that larval feeding by canola flower midge could directly affect yield because galled flowers do not produce seed, however, the economic impact of canola flower midge has been difficult to estimate. Attempts to evaluate the relationship between midge density and canola yield in the field using naturally occurring infestations failed and studies in the laboratory have not been possible because canola flower midge has proven to be nearly impossible to rear in laboratory colonies. For this project, we have leveraged our experience from past research projects to design a field cage study that will be conducted in semi-natural conditions. Further, we will use methodologies recently optimized by K. Van Camp in Dr. Mori’s lab to collect canola flower midge cocoons from the field to reduce the time that canola flower midge will be held in the laboratory. The result of the project will be expanded knowledge of the population dynamics and overwintering survival of canola flower midge as well as improved knowledge to help estimate and understand the potential for canola flower midge to be a pest of the canola industry.