Facts About Mountain Pine Beetles

The mountain pine beetle is a small black beetle that feeds on the bark of pine trees throughout North America. The beetle typically feeds on older trees through the introduction of fungus and the growth of larvae in bark. In recent years, mountain pine beetles have also been feeding on mature trees.

  1. Habitats

    • The small mountain pine beetle, which measures about one-fifth of an inch long, has an expansive habitat. The beetle lives in the pine forests of western North America, from Mexico through the United States into western Canada. Among the trees that the mountain pine beetles live in are the Scots, ponderosa and limber pine trees. Areas of British Columbia have become particularly infested by outbreaks of mountain pine beetles.

    Diet

    • The mountain pine beetle feeds on the bark of pine trees. It does so by introducing a two-pronged attack on the trees. First, the beetle lays its eggs under the pine tree bark. To protect its larvae, the beetle infects the trees with a fungus that prevents the tree from protecting itself with sap. The fungus blocks water flow in the tree as well, drying it out and making it easier for the beetle to eat.

    Life Cycles

    • Mountain pine beetles have a life cycle that lasts for a year. Beetles live in four stages, from eggs to larvae to pupae and then adult. Females can lay 75 eggs at a time. Mountain pine beetles spend their lives in the trees they feed on, from the eggs that are laid beneath the bark to the adults that feed on the bark. Larvae spend winters under the bark, keeping themselves warm by naturally produced glycerol.

    Infestations

    • Mountain pine beetle infestations have caused action throughout the American West and Canada. The beetle was called "the most important insect pest of Colorado's pine forests," by Colorado State University's extension service. More than 40 million acres of forest have been attacked by the beetle in Canada. Officials in both countries have spent millions of dollars and different management techniques to control the reach of the beetle. Cold weather can also help keep the range of the beetle in check.