One of the most damaging insects in North America is apparently no match for a forest fire.

The mountain pine beetle has attacked more than 19 million hectares of forest in western Canada since the early 2000s.

Two years ago, ecologists discovered the beetles in a handful of pines on the border between the Northwest Territories and Alberta.

In July, ecologist with the N.W.T. government returned to find the pine trees gone.

“This year we didn't see any activity of that particular beetle,” says Jacob Olesinski, who monitors threats from forest pests. “Because those stands that it was noticed in two years ago were burned in the recent last year's fire.”

Olesinski says the survey lasted more than a week and covered much of the southern parts of the territory, as well as other pine stands along significant waterways.

He says they found no signs of pine needle discolouration — an indicator of stress caused by the beetles.

He also says the northern climate is too severe for the beetle to survive over the winter, and that last winter's temperatures were especially harsh.

"We are monitoring for it because of the indications of climate change and warming; the winters are becoming warmer, but obviously this is not a factor that can contribute to the spread of the insects in the north, as of yet," says Olesinski.

Janice Cooke, a researcher with the University of Alberta, says the territory still needs to be on the alert for mountain pine beetles.

She says there are active populations in northern Alberta and BC, and as they've reached the territory in the past, they may do so again.

“Northern forests are living on the edge in terms of their climate and what they have to contend with in their harsh environment,” she says. “When you bring in a disturbance like this that hasn't been present in previous millennia, the question is what kind of impact will it have on the entire ecosystem? These forests are pretty fragile environments, just due to the nature that it takes a while to regenerate a forest in the Northwest Territories.”

Cooke says while a survey done in July will detect pine beetle activity from the year before, the ideal time to survey for pine beetles is in September, as that's when the pine needles start to fade after a tree has been colonized by the beetles.

The next survey will be done in the territory next July.