Tamarack trees in northwestern Ontario are slowly falling under threat from the eastern larch beetle — a bug native to the region.

A professor of forest entomology at the University of Minnesota said the beetles — which feast on tamaracks throughout northern Minnesota and Ontario — usually eat trees from the inside out, after other bugs have munched their way through a forest.

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Brian Aukema, assistant professor of entomology at the University of Minnesota, says eastern larch beetle infestations can happen very quickly. (umn.edu)

"The Eastern Larch Beetle likes weakened trees, and it usually comes in after those outbreaks," Brian Aukema said.

"That's been a little bit unusual and it's also been unusual for how long the outbreak has been happening — the better part of 10 years now."

'You can't get them out'

Aukema says most infestations of the beetle last only a couple years, and not a decade. He said climate change may be to blame.

The damaged caused by the scavenging bug is often fatal for the tree, as the beetle gets into the middle of the tree and deprives it of water, killing the tree.

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Eastern Larch Beetle (gov.mb.ca)

When under attack from pests a deciduous conifer can often drop its needles and grow a new set, which is "a great way to get rid of pests," Aukema said.

"But, for a bark beetle like Eastern Larch Beetle, they tunnel through the bark and, once they're in, you can't get them out."

Wood from an infected tamarack may or may not be salvageable, depending on the location of the tree and the severity of the infestation.