clipped from: news.bbc.co.uk   
Beetles tunnel under the tree bark
A plague of tree-killing beetles which swept across British Columbia is threatening to spread east, to the US.

The mountain pine beetle has killed more than half of all lodge pole pine in the province and is now active in neighbouring Alberta.

Cold winters usually kill off the beetle larvae, but the region has been warmer than usual in recent years.

Scientists say the beetle could attack and kill jack pines, which are found throughout North America.
the Beetles do not totally kill the forest
A clearcut
betle kill wood is of little value
The question is, are they going to be able to exploit jack pine to the same degree that they exploited lodge pole pine?

"In places in Alberta there were stories of what they call beetle rain, where under a perfectly blue sky farmers would start hearing what sounded like rain on their tin roofs," said professor Lindgren.

"It turned out it was beetles coming out and falling on the roofs, literally billions and billions of beetles."

Mountain pine beetles occur naturally in British Columbia
numbers have reached plague proportions.