Douglas-fir Beetle

A Technical Report from The Bartlett Tree Research Laboratories

The Douglas fir bark beetle is the most destructive insect pest of Douglas fir, and is the only bark beetle that attacks Douglas fir in western North America. Heavy attack by this beetle can kill trees due to the feeding of larvae in the phloem, eventually girdling the tree and cutting off the water and nutrients from the roots and carbohydrates from the foliage. In addition, the beetle often introduces blue-stain fungi into attacked trees leading to further blockage of the vascular system.