Monitoring the canola flower midge with pheromone-baited traps

Key Result

This project is expected to create an efficient monitoring tool that may be used to scout and forecast canola flower midge populations.

Project Summary

Background

The canola flower midge, Contarinia brassicola, is a recently discovered insect pest of canola on the Prairies. Damage results when larvae feed on developing flower buds which prevents the flowers from opening and forming pods. The population density of canola flower midge is difficult to evaluate as densities are variable across the species range and damage is discreet and can be easily overlooked except under outbreak conditions. Midge control using traditional insecticides is complicated by the cryptic feeding nature of larvae. Larvae feed within developing buds and flowers, which minimizes the time and life stages that are susceptible to control. To develop an integrated pest management program for the canola flower midge, reliable monitoring and forecasting tools are needed to assess midge population densities prior to damage occurring in the field. Synthetic versions of adult produced sex pheromones can be excellent population monitoring tools. This is especially true for species where the adult stages occur before damage in the field, as with canola flower midge. Thus, monitoring adult canola flower midge populations will allow the population density to be determined before damage occurs. Recent work identified the female-produced canola flower midge pheromone and optimized the pheromone blend and dose to create a potent male attractant.

Objectives

The goals of this project are to develop a pheromone-monitoring tool for the canola flower midge and to enhance the knowledge of the factors that contribute to its pest status.
The specific objectives are to:
1) Determine the factors effecting pheromone-baited trap capture of male canola flower midge.
2) Determine the relationship between the number of midges captured on pheromone traps, larval density and damage in the field.
3) Determine the abiotic conditions that effect midge emergence and population densities.
4) Investigate the emergence pattern, longevity and oviposition behavior of the canola flower midge.

Project benefit

Pest monitoring tools are needed across the Prairies to help producers evaluate production risk and increase agricultural and economic sustainability. This project will determine the relationships between the number of canola flower midges captured on pheromone-baited traps and larval population density and damage in the field, creating a tool that producers and agronomists can use to monitor midge populations. This project will also help to determine at what densities midge populations cause economic damage. The project will increase our knowledge of the abiotic factors that affect midge population density. Ultimately, this project will help to determine the pest status of the canola flower midge, assist in promoting plant health and increase and protect the sustainability of the canola industry in Canada.