While many citizens of the GTA had to endure last week’s deep freeze, Toronto’s invasive insect species were snug as bug in … well, not rugs exactly.

But they were cozy enough that those hoping the cold would have the pests buzz off are simply barking up the wrong trees — Toronto’s 860,000 ash trees to be specific. Or whatever is left of them after the ravages of the emerald ash borer, whose presence here was first confirmed in 2007.

Toronto’s urban forestry division alerted the Star to research directed by Brent Sinclair at Western University, which notes “the insect’s supercooling point is about –30C.”

“That’s the point at which half the larvae die,” the research says. “The temperatures have not reached that point. And even if they did, half the larvae would still survive.”

Wind chill apparently has little impact on the little pests, who are nestled under tree bark, insulated from the winds.

“It just hasn’t been nearly cold enough to kill them,” explains Beth McEwen, Toronto’s manager of urban forest renewal.

As for the Asian long-horned beetle, another killer of our tree canopy, its population is probably also intact.

“The Asian long-horned beetle, which is also a concern in Toronto and Mississauga, is well established in parts of Russia that are much colder than here,” says McEwen.

She points out that the daily mean temperature in Moscow for January is 2C lower than it is in Toronto, yet the Russian capital is infested with these beetles.