That is why the spruce bark beetle got spread far and wide on the Kenai,  The Division of Forestry in their wisdom opened up firewood cutting for free and every one flocked to get it and stacked it nice an neat underneath their healthy live trees.  The beetle larvae can live up to three years in the "dead" firewood.  When they flew at 50 degrees next summer... they flew into the nice healthy trees and radiated out from there.  voila infestation