The mountain pine beetle that has decimated large swaths of lodgepole and ponderosa pine forests across western North America in recent years is migrating eastward, according to report by Canadian researchers. 
Scientists at the University of Alberta say they have found evidence that the insect has infested jack pines as far east as Slave Lake in Alberta, about 120 miles north of Edmonton. The jack pine is the dominant pine species of Canada’s boreal forest, which stretches east from Alberta to the Maritime provinces. Since the late-1990s, oubreaks of the mountain pine beetles — linked to warmer winters — have devastated more than 70,000 square miles of forest in western Canada and the U.S. According to the new report, published in the journal Molecular Ecology, the beetle — which can fly — was able to cross a wide swath of forest where lodgepoles and jack pines interbreed to create hybrid trees. While it can be difficult to distinguish between the hybrid trees and jack pines, the scientists used molecular markers to conclude that the infested trees are indeed jack pines. The pine beetles have flourished recently as milder winters have failed to kill the beetle larvae.
iStock
A mountain pine beetle