Key Features
- Pineapple shaped galls at shoot base
- Galls 1/2 inch in diameter
- Green or brown colored galls
Symptoms
A pineapple-shaped gall (1/2 to 1 inch long) is produced at the base of the new shoot growth. Galls can't be removed without cutting twig. Heavy infestations can distort shoot appearance.
Biology
Like Cooley spruce galls, these also open in mid-summer to release the adelgids inside. However, the adelgids remain on the spruce. Greenish, immature females overwinter in cracks and crevices at the base of the buds. In the spring, the eastern spruce gall adelgids mature and deposit eggs under a mass of cottony threads. These eggs hatch about when the buds open and the new needles are exposed. When the immature stage (nymph) hatch from eggs and begin feeding, plants produce bulbous galls containing many cells filled with the nymphs.
Management Recommendations
Usually, damage does not threaten plant heath, and can just be pruned off. Insecticides are rarely needed. To prevent new infestations, inspect plants for last year's galls in the dormant season to target plants that need treatment in the spring. Apply foliar insecticides to plants just after bud-break to kill nymphs that hatch from cottony egg masses at the base of needles. Soil applications of imidacloprid applied and dinotefuran in the fall are effective in preventing galls during the spring.
Effective Pesticides
Active Ingredients include: Acetamiprid, Bifenthrin, Carbaryl, Cyfluthrin, Dinotefuran, Imidacloprid, Insecticidal soap (Potassium salt of fatty acid), Neem oil
