N.S. government treating Cape Breton forest to stop spread of spruce budworm

The eastern spruce budworm is pictured. (Source: Government of Canada)

The Nova Scotia government is treating 1,200 hectares of forest in northwestern Cape Breton this summer to stop the spread of the spruce budworm, a moth that can increase the risk of wood fires.

The province says it will apply a biological insecticide called Bacillus thuringiensis kurstaki to target the budworm in the larvae stage in the Pleasant Bay area of Inverness County. According to the government, early treatment can stop population growth and reduce the need for repeat treatments.

The treatment will be mainly used on Crown lands, but private landowners in the area can opt in for the insecticide.

“By acting early in a small, focused area, we can help prevent much larger impacts on Nova Scotia’s forests in the years ahead,” said Kyle MacQuarrie, ministerial assistant for Natural Resources, in a news release. “Other parts of the country have recently seen the devastation the spruce budworm can have on their forests, and the risk it poses for forest fires. We want to be proactive in managing the effect of this species on our province.”

According to the Government of Canada, the spruce budworm mainly feeds on balsam fir and white spruce, along with red spruce and black spruce. Trees affected by the insect have dried-out needles held together by silk spun by the larvae.

The budworm has outbreak cycles that occur every 30 to 40 years. During these outbreaks, which can last several years, tens of millions of hectares of trees can be severely defoliated.

The most recent outbreak happened on the north shore of the St. Lawrence River in Quebec in 2006. By 2019, more than 9.6 million hectares of forest had suffered moderate to severe defoliation.

The Nova Scotia government says the province’s most recent outbreak of the budworm happened in the 1970s and 1980s, and it affected more than one million hectares of forest.

The province notes the budworm was previously confined to the Cape Breton Highlands National Park, but claims Parks Canada declined to implement an early intervention strategy.

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