Northern Ontario defoliation likely the work of budworm, researcher says

Even when he's on vacation, Taylor Scarr can't help but notice the trees.

Spruce and pine budworm infestations can spread quickly, killing off trees

Scarr says the red colour in the defoliated jack pine trees near Espanola comes from the partly-chewed needles from budworms. (Submitted by Taylor Scarr)

Even when he's on vacation, Taylor Scarr can't help but notice the trees.

Scarr, the director of Integrated Pest Management Research at the Great Lakes Forestry Centre in Sault Ste. Marie, said that on a recent drive home from Manitoulin Island, he noticed that some of the pine and spruce trees didn't look right.

The culprit, he said, are the jackpine budworm and the spruce budworms. As they eat away, the fallen needles collect in the worm's webbing. The needles then oxidize, giving the whole tree a reddish hue.

"The trees look like they've been salt damaged, but normally would disappear by this time of year," Scarr said. "But the trees are still red or they're getting redder now as the needles collect in the webbing and dry."

The defoliation Scarr saw was so severe, he said, that he has concerns of the infestation crossing into the outbreak stage.

"Within one or two years of that damage you can cause some significant mortality of those trees," Scarr said. "The top of the trees can die because the damage is severest in the top one to two metres. And those trees where the tops die they often eventually drop out of the stands as well."

After treetops disappear, it's almost certain the infestation would spread, Scarr said. Researchers are already noticing signs of it in Espanola, Sudbury, Parry Sound and up to Gogama.

In the past, the Ministry of Natural Resources and Forestry consulted with timber companies to gauge the severity of the outbreak, and to see if the forestry industry can harvest wood while it's still viable.

"The Minister of Natural Resources has the option of carrying out an aerial spray program with a bacterial insecticide," Scarr said. "They also have the option of salvage logging, of cutting down trees have been severely damaged.  Or they can redirect the harvesting of trees into the areas where the damage is already occurring."

Scarr said he has recently been in contact with the ministry, and he said they're aware of the problem.

"They have forest health technicians that do aerial mapping of the infestation so they would go up when they're able to," he said. "Because right now, both of us, the Canadian Forest Service where I am and the provincial Ministry are all working remotely and our fieldwork is constrained under the COVID-19 situation."

Scarr said when teams do return to regular work, he's confident they'll be looking at doing more aerial surveys and ground checks to see how severe the infestation is. 


To encourage thoughtful and respectful conversations, first and last names will appear with each submission to CBC/Radio-Canada's online communities (except in children and youth-oriented communities). Pseudonyms will no longer be permitted.

By submitting a comment, you accept that CBC has the right to reproduce and publish that comment in whole or in part, in any manner CBC chooses. Please note that CBC does not endorse the opinions expressed in comments. Comments on this story are moderated according to our Submission Guidelines. Comments are welcome while open. We reserve the right to close comments at any time.

Become a CBC Member

Join the conversation  Create account

Already have an account?