Beetle-killed pine with USGS marker

This dead pine has been marked by USGS scientists studying the effects of mountain pine beetles on forest ecology.

Mountain pine beetle outbreaks can result in the loss of millions of pine trees throughout western North America. The beetles lay eggs and develop in the bark of mountain trees, especially lodgepole, ponderosa, Scotch, and limber pines. The beetles carry bluestain fungus spores, which infect the trees and turn the sapwood a bluish color. Both the beetles and the fungi eventually kill their host trees.