Mountain pine beetle, Dendroctonus ponderosae, is an insect native to the forests of western North America. Previously called the Black Hills beetle or Rocky Mountain pine beetle, periodic outbreaks of the insect can result in losses of millions of trees. Outbreaks develop irrespective of property lines, being equally evident in wilderness areas, mountain subdivisions, and back yards. Even windbreak or landscape pines many miles from the mountains can succumb to beetles imported in infested firewood.
Mountain pine beetles develop in pines, particularly ponderosa, lodgepole, Scots (Scotch), and limber pine. Bristlecone and pinyon pine are less commonly attached. During early stages of an outbreak, attacks are limited largely to trees under stress from injury, poor site conditions, fire damage, overcrowding, root disease, or old age. However, as beetle populations increase, mountain pine beetle attacks may involve most trees in the outbreak area.
A related insect, the Douglas-fir beetle (Dendroctonus pseudotsugae), occasionally damages Douglas-fir. Most often, outbreaks are associated with previous injury by western spruce budworm. spruce beetle (Dendroctonus rufipennis) is a pest of Engelmann and blue spruce in Colorado. Injured pines also can be attacked by the red turpentine beetle (Dendroctonus valens).
Mountain pine beetles, and other bark beetles in the genus Dendroctonus, can be separated from other bark beetles by the shape of the hind wing cover. In side view, it is gradually curved. The wing cover of Ips or engraver beetles, another common group of bark beetles attacking conifers, is sharply spined. In Scolytus beetles, such as the shothole borers and European elm bark beetle, the area under the wing cover (abdomen) is indented.
When treating pine beetle infested logs, the most common treatment has always involved the use of the insecticide "Lindane." Sometimes the logs are covered with plastic as well. Since the last beetle outbreak on the 1970's, Lindane has been banned in most forms. Because of this, and to be more environmentally friendly, we now use a solar treatment on infested logs as outlined by the U.S. Forest Service.
The best time to check for Pine Beetle attack is in winter. Check for "pitch tubes" on the trunks of your trees. If you see pitch tubes, cut a piece of bark off and see if the wood under the bark is discolored bluish-gray. If so, the tree(s) need to be removed.
LAM Tree Service is available in winter to inspect your property for beetles. We charge an hourly fee for this service.
For more information, click on the following link: Mountain Pine Beetle