Organic brassica industry invited to take part in a national AAFC survey of the Cabbage Maggot

Potato Research Centre scientist Josée Owen is looking for volunteers in the organic community to collect flies and pupae in vegetable brassica crops this year as part of a national survey that is intended to give researchers a better handle on two aspects of the destructive Cabbage maggot - the species involved in creating the damage, and how pesticide resistance is spreading.

The study is focussing on broccoli, cauliflower, rutabaga, cabbage, Chinese cabbage, radishes and other vegetable brassicas.

Although one fly, Delia radicum, has always been thought to be responsible for the crop damage, it’s possible that different species of the Delia fly are at work in the different crops.  The survey will collect samples from conventional and organic vegetable brassica fields.

The study will also look at pesticide resistance in the fly populations. Currently just one insecticide is registered in Canada for the Cabbage Maggot, chlorpyrifos (LorsbanTM), and the insect is showing growing resistance to the product.  The results of the study will lead to more efficient use of the pesticide, and support research on alternative control practices, some of which may take several years to become widely accepted.

“We’re hoping to team up with the people who are already coming to the farm, like scouters and IPM advisors, who will be able to set up the sticky traps and preserve and send us the samples,” says Owen.  “But we are also very open to growers who want to participate and feel comfortable doing it themselves.”

Funding is available to cover the cost of traps and postage and, in some cases, student labour and the cost of travelling to field sites.

“The goal is to survey as many fields as possible for as little cost as possible to maximize our reach,” says Owen.  “Where we can, we want to piggyback on existing IPM scouting or partner with crop advisors who are routinely visiting growers fields.”

Owen says the involvement of the organic industry in the survey is crucial, even though organic growers do not use insecticide.

“Including growers with a range of production practices, such as organic, helps us understand the pest not just at the field scale but at a regional scale,” says Owen. “Data from British Columbia suggests that the presence of organic farms and farms with a good Integrated Pest Management practice, in a local region can delay pesticide resistance in that region and we want to get more data on that.

“It underlines the value of diversity in our cropping systems, and the value of organic production to conventional growers.”

To find out how to participate in the survey, call or write a quick email to Josée Owen.  She will give you more information about how to be involved, and guide you to a more local contact.

Josée Owen
Researcher/Cabbage Maggot Fly Project Lead
Agriculture and Agri-Food Canada

(506) 460-4469