Mitigating Resistance in European Corn Borer to Protect Bt Corn in Canada
The European corn borer (ECB) has long been a significant pest for corn production in North America, causing yield losses and harvest challenges. Genetically modified Bacillus thuringiensis (Bt) corn, introduced in 1996, revolutionized pest management by expressing insecticidal proteins from Bt, reducing ECB damage and mitigating losses. Today, 85% of Canadian corn acres are planted with Bt corn. However, the sustainability of Bt corn is under threat due to resistance development in ECB populations.
In 2018, the first confirmed case of practical field-evolved resistance to Bt corn in North America was discovered in Nova Scotia. This resistance to the Cry1F protein poses a significant challenge to maintaining Bt corn’s effectiveness. To address this, a multidisciplinary research team, led by Drs. Jocelyn Smith and Rebecca Hallett from the University of Guelph, is collaborating with a diverse network of industry and government partners through an NSERC Alliance grant, including:
This diversity of partners across Canada ensures that research outcomes address region-specific challenges while creating a unified national approach to sustainable pest management. The project focuses on understanding Cry1F resistance in ECB, mapping its distribution, assessing susceptibility to other Bt proteins, and evaluating strategies to enhance insect resistance monitoring (IRM) using molecular tools. This collaboration is essential to protect Canadian agriculture, maintain Bt corn’s viability, and support farmers across the country.
The partnerships established through this project have facilitated expanded collecting and testing of ECB populations across eastern Canada using sentinel plots with seed provided by industry partners. A major breakthrough of this project has been the identification of molecular markers linked to Cry1F resistance in ECB, published in Scientific Reports in 2023. These markers are now being used internationally to enhance insect resistance monitoring of Cry1F. This has led to additional collaborations including U.S. researchers screening ECB populations under a USDA grant and applying a novel targeted sequencing technique developed by the University of Tennessee. The collaborations fostered by this project have strengthened knowledge transfer nationally and internationally, ensuring that corn producers across Canada, as well as U.S. researchers, growers, and regulatory bodies in both countries receive the latest research findings and extension information.
Photo: European corn borer feeding on Cry1F corn Hybrid (left below - courtesy of Jocelyn Smith). European corn borer larva (right below - courtesy of Jocelyn Smith).
*This research took place, in part, at the Ontario Crops Research Centre sites in Ridgetown and Winchester, which are owned by Agricultural Research and Innovation Ontario and managed by U of G through the Ontario Agri-Food Innovation Alliance.
