Spruce Gall Control
SPRUCE GALL (EASTERN AND COOLEY)
What you’ll see …Eastern Spruce Galls are galls that form at the base of the new shoots in the spring. Galls will be about ¾ of an inch in length, and pineapple-shaped. By autumn the galls are brown and the shoot growth beyond them is dead. If infestation is severe the host tree will have the appearance of dying from the perimeter inward. Cooley Spruce Galls are galls that form at the tip of the plant, they can be green or purple sausage-shaped and typically about 21/2 inches long; and the entire shoot of any spruce species becomes a gall, they’re usually brown and turn downward. By late fall both the Eastern and Cooley’ Galls will dry, turn brown or grey, and crack open; immature Adelgids will emerge and mature into winged, egg laying females.
The reason for the problem… Eastern Spruce Gall: in spring, over-wintering immature female Adgelids (adelges) can be found at the base of the buds of the host plant. In the spring they resume development and lay eggs at the time of bud break; eggs hatch immature Adelgids and begin to feed on new needles; this feeding activity stimulates gall formation. Cooley Spruce Gall: in spring, newly hatched nymph Adelgids feed at the base of the needles near the branch tips, causing the entire new shoot of the spruce species to form a gall. The Adelgids then complete their maturation within the gall during the summer.
You Should… in extreme cases prune off the Cooley Spruces Galls to help minimize the overall appearance and insect population. This won’t be practical in all situations.
We can help by…deep root feeding your landscape in the fall using systemic insecticides. Oil sprays will cause your Colorado Blue Spruces to turn green and have on occasion caused plant damage in the early spring when temperatures fluctuate drastically.
Related Plant Types
Posted on: August 4, 2015
What you’ll see…is wilting leaves and dieback of branches, often one at a time or on one side of the tree. This can occur over a number of years, with remiss...