Spruce budworm contributes to surge in Northern Ontario wildfires

Northern Ontario has experienced a surge in wildfires in 2026, with 687 reported fires compared to 442 in 2025 and a 10-year average of 481. While dry weather is a primary driver, the spruce budworm has emerged as a significant contributing factor.

The spruce budworm, a destructive pest in North American spruce and fir forests, causes extensive tree damage through defoliation. Jean-Noel Candau, a research scientist with the Great Lakes Forestry Centre, noted that the current cycle began around 2015. This defoliation can turn large swaths of the canopy reddish-brown and increase wildfire risk significantly between three to nine years after the initial damage. The infestation is currently more advanced in the northeastern portion of the province.