Cooley Spruce Gall Adelgid
Attacks:
Colorado spruce, white spruce, Norway spruce, Douglas fir
What you will see:
- Large brown pineapple–like structures at end of twigs
- Large green pineapple-like structures at end of twigs
- Small cotton ball-like egg masses
Life cycle:
- Overwinters as females attached to the current year’s twigs at the bases of buds
- Females mature and lay 150 to 200 olive-green eggs Eggs hatch into yellow nymphs
- Nymphs move to needle bases to feed and form galls
- Nymphs molt three times in the gall and emerge in August and September
- Mature nymphs crawl to needles and molt into winged females
- Nymphs lay a second generation of eggs (up to 60) then die
- These eggs hatch into the overwintering females
Cultural practices:
- Remove and destroy green galls
- This technique is only effective where the trees have few galls
- Plant less susceptible trees (true firs)
- Effective chemical treatments include systemic and foliar insecticides. Follow your Consulting Arborist’s recommendations.
- An integrated approach
- When caring for urban trees it is important to make a complete evaluation of all environmental conditions to accurately diagnose all stress factors and prescribe care based on specific circumstances. This prescriptive care will help your tree meet its full potential.