2011-04-27

Mountain Pine Beetle Perched to Move Eastward

Now that the mountain pine beetle has chewed through some 70,000 square miles of forest in the western states and Canada, it seems the voracious pest is expanding its palate. Beetles in Canada were recently discovered attacking jack pines (Pinus banksiana) for the first time, a break from their usual diet of lodgepole (Pinus contorta), according to a study published this month in the journal Molecular Ecology. With this switch in taste, the beetle could be setting up to cross the continent via the vast Canadian boreal forest, putting trees on the East Coast at risk.

Up to this point, the mountain pine beetle has munched mainly on lodgepole-dominated forests in the western U.S. and Canada. But at the eastern edge of Canada’s lodgepole range, hybrid lodgepole-jack pines may have helped the critters switch to the eastern species. Scientists from the University of Alberta who authored the new study were able to verify that purebred jack pines as far east as Alberta’s Slave Lake had fallen to beetle attack.

The pine beetle’s leap to jack pine has been anticipated—indeed feared—by biologists for a decade. High Country News contributing editor Michelle Nijhuis reported on that prediction in 2004 in her article, ”Global Warming’s Unlikely Harbingers.”