After beetles attack a tree, they mate, and baby beetles are soon hatched. Growing through the fall and winter beneath the bark, the larvae are susceptible to extreme cold weather. They feed on the tree’s phloem to help build up their reserves of glycol, an antifreeze, the key that keeps the beetles alive until spring and their eventual search for new pine. The beetles, by the coldest months of winter, are hardy enough that it takes severe, sustained temperatures toward -40 to kill them.
On his knees in the forest, carefully chiseling away the bark of a felled pine, Mr. Jones points to two black specks, barely the size of a pen tip. “There’s ma and pa,” he says. There are burrows away from the parents. This tree hasn’t been particularly savaged. “It can be a busy place under the bark of a tree that’s in bad shape,” he says. “And once they’re tucked in, they’re really resistant.”
“Sharp shocks” can score early kills. In the autumn, when the larvae are building their glycol reserves, if the temperature spikes suddenly lower to levels such as -25 from above zero, death can be widespread, as happened in December, 2008 and October, 2009. Another similar shock happened in March, 2010, just as the beetles were shaking off their winter defences.
In fact, bad outbreaks of pine beetle have occurred several times in the past century in British Columbia and Alberta, but severe cold eventually stopped the spread.
Complacency is what led to the B.C. disaster. By the early 2000s it was too late. “It took us a while to actually realize that it was different than a normal cycle,” said Bob Clark, a retired B.C. government forests official, who subsequently consulted to Alberta.
The strategy in British Columbia for several years now has been to harvest as much viable dead pine – before it’s completely decayed – to turn it into something useful, some of it lumber, some pulp, some wood waste for bioenergy.
At West Fraser Timber Co. in Quesnel, a small city at the heart of the plague in the B.C. Interior, the largest sawmill of North America’s largest lumber maker was completed three years ago for $120-million. It was specifically tailored for deadwood, replacing a less efficient mill. New technology intensively scans the flawed logs that hurtle through the mill, so the minimum of wood is trimmed and maximum value can be cut from the pine. “We’re in a full-scale salvage operation,” said Dave Lehane, a West Fraser vice-president.
North of Quesnel in Prince George, at the University of Northern British Columbia, scientist Dezene Huber is working on beetle DNA, in a coordinated multi-university effort to understand the insect and better attack it in the future. Analysis of genes reveals details of what’s clearly a formidable opponent. The genes involved in producing glycol to insulate beetle larvae through winter are similar to those that allow human marathon runners to endure long distances in a starvation-like state.
Prof. Huber, looking at the “economic tragedy” that’s waylaid small cities in the province’s Interior, calls the beetle in British Columbia a “slow-burning forest fire.”
“When you see a wildfire, a lot of times the gut reaction is: ‘What a phenomenal thing to see,’” Prof. Huber said. “But is it just burning harmlessly away from people – or is it on the edge of a town? Then it’s amazing, in a horrible way.”
Looking at Alberta, Allan Carroll is encouraged but ever-wary. Mr. Carroll, then a senior scientist for the federal government, watched for more than a decade as the beetle destroyed B.C.’s pine-heavy forests. Now, after counselling the Alberta government, and as a researcher at the University of British Columbia, he warns that the most dangerous misstep is an eased effort.
He likens it to department-store credits cards, whose usurious interest rates loom even if the balance owing is halved. The beetle could easily “blow up again in everyone’s face,” he said. “In Alberta, in the areas where we’ve watched it, it’s had the capacity to double, or triple, every year,” Mr. Carroll said. “That’s one heck of a big interest rate.”
Beetle biologyReport Typo/Error