The Cooley Spruce Gall Adelgid is an aphid-like pest. 

What are the Risks?

Adelgid's feed on spruce and Douglas fir. The adelgid injects saliva into its host when feeding, which is toxic to the tree, and as a result prohibits bud formation thus causing long-term tree decline. 

What to Look For

The adelgid is aphid-like and inconspicuous.  It's life cycle consists of six different forms.Spruce Gall Adelgid

  • first form - formation of galls on branch tips;
  • galls later turn reddish brown and dry out; and
  • remaining forms - feed openly on needles.


  • Pick off new galls and burn them; and
  • Insecticides used for aphid control may help decrease population levels in early spring.

Related Links

Cooley Spruce Gall Adelgid