In Alberta's drawn-out fight against mountain pine beetles, slowing the invasion is as close to winning as the province will get, researchers say.

mountain pine beetle

Mountain pine beetles burrow into the bark of their hosts. (Supplied/Nadir Erbilgin)

"They're pushing eastward and they certainly are knocking on the door of Saskatchewan," research scientist Allan Carroll said about the destructive bark beetle.

"We can win the battle if it means simply slowing the spread, because if we slow the spread we have all kinds of options to deal with it when it finally does get to Saskatchewan."

Carroll, a forestry professor at the University of British Columbia, is one of four scientists studying Alberta's management of mountain pine beetles.

"The effort and money spent by the province of Alberta is really staggering," Carroll said.

"They've been going for 10 years now without letting up. It's certainly very impressive and indeed the results that we found in our research in terms of the successes are only possible with this level of commitment."

Almost $500 million invested

Battling the beetle cost $484 million from 2004 to 2016, according to Alberta's senior forest entomologist, Mike Undershultz. Both Saskatchewan and the federal government contributed to the funding.

But it's not enough money to end the beetle's creeping march across the province, Undershultz said.

"There's a ton more beetles to control than there is money in a year," he said. "We need to get pretty strategic with where we put our resources."

Alberta Agriculture and Forestry is working to prevent damage in specific locations and to protect valuable resources, such as watersheds.

Undershultz estimated the province has saved more than half a billion trees from deadly infestations.

There's no way of knowing what would have happened if Alberta hadn't launched a management strategy 10 years ago, Undershultz said.

"It's kind of some 'napkin science,' " he added.

The province has since used methods such as prescribed burns and targetted logging to slow the beetle's progress.

"All of the scientists told us, 'If you want to have success, you need to be aggressive and you need to be sustained,' " Underschultz said. 

"So that's the one thing we've taken to the bank."

Research findings released by Carroll and his team in 2017 suggest the province has reduced the beetle's spread by 30 per cent.

"They're very aggressive in the way that they're managing the beetle and they're very consistent," Carroll said. 

"If we can continually be aggressive against this outbreak population, to the extent that we can cause it to collapse, then the eastward spread might not happen in our lifetime," he added.

"However, if we back off and abandon the effort, if we allow outbreak population to persist, then the likelihood of beetles moving east in the short term is much, much higher." 

Six million hectares at risk

Mountain pine beetles are chewing into the forestry industry, though Undershultz was unable to put a figure on the loss.

Alberta's forest sector employs 19,600 people and contributes up to $6 billion annually to the provincial economy.

Approximately six million hectares of pine are at risk of attack by the beetle, he said. More could fall victim if conditions are favourable.

Afflicted trees can sometimes still be used for lumber, Undershultz added.

Pyramid Mountain pine beetle

Dead trees, killed by mountain pine beetles, glow orange near Pyramid Mountain in Jasper National Park, Alberta. (Wallis Snowdon/CBC)

Despite aggressive attempts to hem in mountain pine beetles, the insect has been recorded within 50 kilometres of the Saskatchewan border.

Two mass migrations, one in 2006 and another in 2009, brought the beetle into central and eastern Alberta.

"Billions and billions of beetles rained down hundreds of kilometres from where beetles had ever been before," Undershultz said.

The species usually travels about one kilometre per year, he added.

Fire and ice

Nadir Erbilgin, a forest entomologist at the University of Alberta, said the beetles now face an expanse of fresh territory without natural barriers.

Pine trees east of B.C. have not adapted to the beetle, making them vulnerable to attack and destruction.

Since creeping through the Rocky Mountains more than a decade ago, Erbilgin said the beetle's eastward march has been slow but inevitable. 

"The mountain pine beetle is here to stay," he said. "I don't think they're going to disappear from the landscape."

Fire can destroy the beetle and its preferred habitat of pine trees.

"Fire creates a very different age class of forest, increases the species diversity, which mountain pine beetle don't like," Erbilgin said.

Extremely cold winters can also wipe out the beetle, Erbilgin said. Temperatures need to drop below – 40 degrees for at least a week to kill about 99 per cent of an infestation, he added.

'You're not wasting resources. If you don't do it, the beetle will come and punish you.' -  Nadir Erbilgin, University of Alberta entomologist 

The early winter months of 2017 are predicted to be warmer than usual, according to forecasts by Environment Canada.

"Climate seems more suitable now in Alberta for mountain pine beetles than ever before," Erbilgin said.

Without fire and ice to knock back the beetle, he said humans are its greatest threat in Alberta.

To protect native pine species and to shelter the forest industry, Erbilgin said the province needs to continue a war that likely won't end.

"You're not wasting resources," he said. "If you don't do it, the beetle will come and punish you."