European corn borer resistance to Bt (Bacillus thuringiensis) corn

European corn borers that have developed resistance to corn hybrids expressing the Bt insect control trait known as Cry1F have been found in Nova Scotia in both King's County and Colchester County. These insects are the first case in Canada of European corn borers developing resistance to an insect control trait.

What is the European corn borer?

European corn borer is a pest of corn, peppers, snap beans, potatoes, tomatoes, apples and other horticultural crops. European corn borer larvae can damage all above-ground plant parts of many crop kinds, including causing damage when they feed on the ears of corn.

More information on the biology of the European corn borer can be found in the Ontario Ministry of Agriculture, Food and Rural Affairs factsheet on European corn borer in sweet corn and other horticultural crops.

What are Bt traits?

Bacillus thuringiensis (Bt) is a naturally occurring bacterium that produces a protein that is effective for the control of several insects, such as flies, mosquitoes, Colorado potato beetles and corn borers.

Farmers have been using Bt since the 1920s, and it has been commercially available since the 1950s. Plants genetically modified to express Bt protein(s) are capable of controlling targeted insect pests (as opposed to farmers broadly spraying this insecticide on their crops to protect them). A list of the plants containing insect control traits currently approved for environmental release in Canada is available in CFIA's database of approved plants with novel traits (PNTs).

More information on Bt corn can be found on the Canadian Corn Pest Coalition website.

What is CFIA's role in the oversight of plants expressing insect control traits?

CFIA assesses the environmental safety of plants with novel traits in Canada, including plants that express insect control traits as a defence against insect pests. CFIA requires developers of such plants to implement insect resistance management (IRM) stewardship plans.

An IRM plan is designed to delay targeted insects from becoming resistant to insect control traits. An IRM plan details the strategies that allow these PNTs to be used safely and sustainably.

What actions should farmers take if they are growing crops with European corn borer insect control traits?

The following resources outline options to help farmers manage European corn borer:

• CCPC mitigation recommendations for European corn borer resistance to Bt corn
• Ontario CropIPM - European corn borer