Pine: Mountain pine beetle

categories: Conifers Ornamentals Pine Pine Insects

revision date: 2024-06-05 02:07

Bark beetle larval galleries.
Bark beetle larval galleries
Photo by: A.L. Antonelli


The mountain pine beetle attacks pine trees (trunks and branches) 4″-5″ in diameter or larger. The adults and larvae mine the bark, weakening and girdling trees. Heavily infested trees may decline or die. Red sawdust on the bark and ground and pitching on the trunk or large branches may indicate the presence of these bark beetles. Adults are black and about 1⁄4″ long. Larvae are white and found under the bark in straight galleries. Bark beetles typically attack weakened trees. Lodgepole pine is the preferred host, but other pines are also attacked.

Management Options

Use Integrated Pest Management (IPM) for successful plant problem management.

Non-chemical Management

Select non-chemical management options as your first choice!

  • Provide proper culture for trees. Healthy, vigorous trees are much more resistant to beetle attacks.
  • Remove severely infested trees to prevent possible infestation of nearby trees.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

  • Make applications in early June or prior to beetle flight.
  • Apply from ground level to limbs 5 inches or more in diameter.
  • This is a preventive treatment spray and will not control or kill beetles once they have entered the tree.
  • Sevin (carbaryl) is particularly dangerous to honeybees since it does not immediately kill them. They return to the hive with the poison and distribute it within. Therefore avoid carbaryl if any possibility of spray drifting onto nearby blooming plants.
  • Homeowners should not make foliar applications to trees over 10 ft tall.
  • Consult a commercial pesticide applicator for treatment of trees and shrubs over 10 ft. tall.

Approved Pesticides

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.

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