Adelges cooleyi (Hemiptera: Adelgidae)
Cooley Spruce Gall Adelgid
Deming, Whatcom County, Washington
September 10, 2012

Douglas fir needle with two dead adelgid females. One young nymph is visible to the rear of the second female. Females shelter eggs under their wings and abdomens and die on the spot where they laid their eggs. These adelgids will feed on the Douglas fir needles. Some of this generation on Douglas fir will develop wings and fly to a spruce, where they will overwinter in preparation for laying eggs in the spring. The generation that lives on the spruce will cause galls, but no galls are induced by the adelgids on Douglas firs.