Have you ever noticed tiny blue spruce tree cones? Often these are not cones but are a growth known as Cooley Spruce Galls caused by the insect known as the “spruce gall adelgid” Which is a type of wooly aphid. When spruce buds swell in spring, adelgids hatch eggs and thus young insects that feed on new needles. This causes a cone-like gall growth to form. While they can be concerning to homeowners, they are not harmful except for cosmetic disfiguring. The galls can be easily pruned off.