Colorado Dendroctonus Beetles

bug Symptoms:
  • Reddish to yellowish boring dust on the bark
  • Large entry and exit holes
  • Pitch out, sap being pushed out of the trunk as a natural defense that trees have to try and prevent the beetles from establishing in the cambium layer

There are 12 types of Dendroctonus beetles found in the west.  Dendroctonus means tree killer, these types of bark beetles are the most destructive to trees and include spruce beetle, western bark beetle, mountain pine beetle, and douglas fir beetle.  These beetles are large in size and pose one of the greatest threats to high value trees in Colorado.  If activity is observed in close proximity to private high value trees of the same species we do recommend preventive measures including trunk sprays, soil injections or trunk injections. There is generally one generation per season.