Sibling-broods
Guides
Dendroctonus pseudotsugae
Douglas-fir beetle, Douglas fir beetle
The Douglas-fir beetle (Dendroctonus pseudotsugae) is a bark beetle native to western North America and a major pest of Douglas-fir (Pseudotsuga menziesii). Adults are small (4.4–7 mm), light brown when young, darkening to brown or black with reddish wing covers. Outbreaks typically follow disturbances such as storms, fire, or drought, which provide stressed or dead host trees. The species has one of the most thoroughly studied pheromone systems among bark beetles, with operational use of its antiaggregation pheromone (MCH) to protect high-value trees developed over 40 years of research. The beetle also infests downed western larch (Larix occidentalis), though brood do not survive in live larch due to high 3-carene content.