Christmas tree (Douglas-fir)-Cooley spruce gall adelgid

Adelges cooleyi

Pest description and crop damage Adelgids appear as small cottony tufts on underside of needles. May cause yellowing, distortion, and premature needle drop. Aphids may distort stems.

See table:

Management-chemical control

Apply to control crawler stage, usually when new growth is expanding in spring.

  • bifenthrin (Brigade, OnyxPro, Sniper and others)-Restricted use pesticide. (Group 3)
  • carbaryl (Sevin and others)-(Group 1)
  • chlorpyrifos (Lorsban Advanced, Warhawk and others)-Restricted use pesticide. (Group 1)
  • cyclaniliprole (Sarisa)-(Group 28)
  • cyclaniliprole (Group 28) + flonicamid (Group 29)-Pradia
  • dinotefuran (Safari 20 SG)-Check registration status at time of application. (Group 4)
  • imidacloprid (Admire Pro, Prey 1.6 and others)-(Group 4)
  • insecticidal soap (M-Pede and others)-Some formulations are OMRI-listed for organic production.
  • spirotetramet (Ultor, Movento)-(Group 23)
  • sucrose octanoate (SucraShield and others)-Some formulations are OMRI-listed for organic production.
  • thiamethoxam (Flagship 25 WG)-(Group 4)