The tiny and determined pine beetle wants to get into southern Alberta's Rocky Mountain forests badly, and the province is preparing to torch valleys to stop it.

A full-scale epidemic raging in neighbouring British Columbia is threatening to destroy 80 per cent of mature pines, and Alberta is frantically trying to slow the insect's voracious march eastward.

One of the first key steps is one of the largest planned forest fires ever in the region. In all, 1,300 hectares are targeted near Mount Nestor, south of Canmore, Alta., an area that straddles Banff National Park and the provincial Spray Valley park.

If weather conditions are dry, the fire will be ignited later this fall, killing some beetles in its path, but more importantly taking out a good stretch of  "host trees" and creating a natural barrier, much like the way forest fires are controlled.

"This is the battle line, the border, right now," says Rob Harris with Alberta's Sustainable Resource Development, pointing westward from a mountaintop to the British Columbia boundary.

"You skip right over those mountains there and, pow, you're in beetle country."

Patches of red in the green blanket of forest in one of Alberta's most popular mountain recreation areas are telltale signs that the beetles are on the move — catching wind currents that carry them hundreds of kilometres over mountain ranges and funnel them down the valleys.

It's easy to see where they've come from. The view from a helicopter flying west shows the green soon turning to red. Next come the areas that have been clearcut.

Instead of trying to contain the insect and halt its advance, crews are resorting to 'salvage logging' and are extracting whatever economic value is left in dead trees before they're too dry and cracked to go through the mills.

"British Columbia is measuring mountain pine beetle impacts by the millions of hectares and Alberta is still counting single trees," says Dr. Allan Carroll, one of Canada's top mountain beetle researchers with the Canadian Forest Service.

Put another way, Alberta figures it has upwards of three million to four million trees afflicted, while B.C. has 14 million hectares of pine forest in some level of infestation — about four times the size of Vancouver Island.

"We have the potential to do something in Alberta, whereas in B.C., it's all been directed toward salvaging the dead trees."

Carroll says a "huge concern" is trying to slow the beetle's advance into the boreal forest, which touches the corners of northern B.C. and Alberta, and stretches eastward across Canada.

While pine beetles have always been present in forests and regional infestations have occurred from time to time, the absence of sustained cold-weather snaps in recent winters has been a key factor to the current crisis.

Dave Dalman, a land-use manager with Parks Canada, says while the national parks prefer to allow nature run its course, it will engage in prescribed burns to control insects and regenerate the land.

"We are sort of the meat in the sandwich — having an epidemic on one side of us and healthy, productive forests on the other side," he says. "And some of the key valleys that run through the national parks in Banff, and Jasper, and Yoho and Kootenay could well be a conduit. So we need to manage the situation." 

Most of Alberta's pine beetle damage has been in the northwest corner around Grande Prairie. In the south, the Rockies have helped slow the beetles from sweeping eastward.

B.C. beetles headed for collapse: expert

Carroll and other pine beetle experts predict that the B.C. epidemic will likely be over in another five to six years as the insect literally eats itself to death by killing all the older host trees. The population there is likely to collapse within itself and, with fewer beetles taking to the winds, the pressure on Alberta should wane.

"The bad news in B.C. is they're eating themselves out of house and home," says Rod DeBoice, that province's top pine beetle co-ordinator. "But that's good news for Alberta."

DeBoice says Alberta also benefits from having "a more restricted geography" with the Rockies, as opposed to the interior of British Columbia, which is generally flat and homogenous.

He says Alberta stands a better chance of avoiding the whole-scale devastation of its neighbour, but he adds a caveat — "unless they're in this unprecedented epidemic steamroller."