Mountain pine beetles (MPB) are the most important insect pest of Colorado's pine forests. MPB often kill large numbers of trees annually during outbreaks. Trees that are not growing vigorously due to old age, crowding, poor growing conditions, drought, fire or mechanical damage, root disease and other causes are most likely to be attacked. For a long-term remedy, thin susceptible stands. Leave wellspaced, healthy trees. For short-term controls, spray, cover, burn or peel attacked trees to kill the beetles. Preventive sprays can protect green, unattacked trees.  For more information, please read Trees & Shrubs (Issue No. 5.528) by D.A. Leatherman, I. Aguayo, and T.M. Mehall.  Additional information can be found on the Colorado State Forest Service website and at Mountain Pine Beetle Life Cycle.

Ips beetles, sometimes known as “engraver beetles,” are bark beetles that damage pine and spruce trees. They develop under the bark and produce girdling tunnels that can cause dieback and kill trees.  Ips beetles rarely attack healthy trees.  Most problems with ips occur to newly transplanted pines or when plants are under stress.  Several generations of ips can occur in a season.  There are 11 species of ips beetles found in Colorado.  For more information, please read Trees & Shrubs (Issue No. 5.558) by W. Cranshaw and D.A. Leatherman.  Additional information can be found on the Colorado State Forest Service website.

The red turpentine beetle (Dendroctonus valens LeConte) is the largest and most widely distributed bark beetle in North America. It belongs to a group of beetles that characteristically mine between the bark and the wood of trees. The red turpentine beetle is a common pest of forest, shade, and park trees of pole size or larger. For more information, please read Red Turpentine Beetle by Richard H. Smith.