Adelges Piceae (exotic pest from Europe)

Photo by Robert L. Anderson, USDA Forest Service,

Signs & Symptoms

Photo by Arthur Antonelli, Washington State University.

  • Yellow needles and premature needle loss
  • Flat top or crooked terminal
  • Gouting (swelling) around buds and internodes
  • Stiff, inflexible trunk and swollen lateral branches
  • White, cottony masses on trunk and large branches
  • Dead shoots or branches

Where to Look

Photo by Robert L. Anderson, USDA Forest Service,

  • Localized areas in the field

Similar Symptoms As

Photo by Chal Landgren, OSU.

  • Root problems
  • Severe aphid damage


  • Scout at waist height for swollen areas (white, cottony masses) in branches and main trunk.
  • Check flexibility of the upper stem.
  • Look for poor growth of trees or affected trees that have lost flexibility in the upper stem.
  • Examine stumps for reddish discoloration.

Management Options

  • Spray insecticides at high volume and pressure during the first generation crawler stage.
  • If the adelgid is found, treat the field prior to bud break of the following season.
  • Clear-cut infested blocks. Do not leave infested trees in the field, and avoid cutting during crawler activity.

Host Susceptibility

host susceptibility graph

  • High susceptibility: Fraser fir, Balsam fir
  • Medium susceptibility: Noble fir, Shasta fir
  • Low susceptibility: Grand fir, Nordmann fir, Turkish fir

Management Calendar

  • Look for swollen branch nodes and terminals: All year round
  • Check for eggs and cottony tufts: April through Mid-May
  • Check for crawlers, using a hand lens: Mid-MAy through October
  • Spray insecticide (if needed) at/near bud break: May through July