Adult mountain pine beetles prefer large diameter trees, according to the Canadian Forest Service.

The mountain pine beetle has been spotted in Grande Prairie, further north in Alberta than experts had expected.

The discovery of the efficient tree killer has the Alberta government asking residents of the small city northwest of Edmonton to call a hotline to report infested trees.

"It's always been thought the mountain pine beetle could never go that far north because it is too cold, so it's outside of their range," said Michel Proulx, a spokesman with Alberta Sustainable Resource Development.

Devouring British Columbia's forest

Each mountain pine beetle is the size of a grain of rice, but the voracious insects have already devoured an area of B.C.'s forest the size of Iceland.

The beetle has been spreading east across the Rocky Mountains since 2002, mostly in Willmore Wilderness Park and areas around Canmore.

Grande Prairie is now the farthest north and east the beetles have travelled.

Provincial officials will work with the City of Grande Prairie to cut and burn infested trees this winter, before the bugs attack other trees.

Bug threatens jack pine

Northern Alberta is home to jack pine forests, prompting concern, said Proulx.

"Scientists believed that the mountain pine beetle could only survive and thrive in lodge pole pine. But now they think, and have seen evidence, that mountain pine beetle can survive and thrive in jack pine," he said.

If the beetles make the jump, an infestation could wipe out billions of trees in the boreal forest all the way to the East Coast.

Alberta'sbeetlehotline number is 1-877-927-BUGS (2847). Signs of a pine beetle problem include a brown crystallized substance on the trunk of the tree, as well as sawdust around the base.

Grande Prairie is 455 kilometres northwest of Edmonton.