Discovered in Canada and now Connecticut, ECB spread would be a major pest problem not seen for decades.

The European Corn Borer (ECB), one of North America’s most destructive crop pests, has been effectively managed for more than 25 years through the widespread adoption of Bt corn. However, the recent discovery of field-evolved resistance to Bt toxins — first in Canada and then in Connecticut — has raised concerns about its potential resurgence as a significant agricultural threat.

Kelsey Fisher, assistant scientist with the Connecticut Agricultural Experiment Station in New Haven, addressed an attentive audience at the 35th annual Iowa State University Integrated Crop Management Conference in Altoona.

Fisher noted that ECB, nearly eradicated through transgenic corn engineered to produce insecticidal toxins, has begun to show signs of resistance. The first case of resistance was detected in Nova Scotia, Canada, in 2018. Subsequent monitoring revealed additional resistant populations in Quebec and...