A small, dark, cylindrical bark beetle that attacks and kills standing, living, pine trees including lodgepole, ponderosa, and western white pine. Although normally limited to highly stressed trees within pine forest ecosystems throughout western North America, certain circumstances (e.g., unusual hot, dry summers and mild winters in forests filled with mature lodgepole pine) can lead to destructive epidemic outbreaks. The current outbreak of mountain pine beetle in British Columbia, the largest in Canada's history, has destroyed millions of lodgepole pine-the province's most commercially harvested tree