The budworm, especially the Spruce Budworm, is very disruptive to ornamental trees, including spruce, fir, Douglas fir, pine, larch, and hemlock. The budworm attacks the tree by chewing the ends of new tender needles. If infested by mid-July, the ends of the branches look reddish brown and the needles look clustered or webbed together. Repeated infestations can cause branches to die and, over several years, the tree may also die.
The budworms appear as green or reddish brown caterpillars about 1 and ¼ inch in length. Budworm infestations normally occur in cycles that last a few years. During outbreaks, it is important to take steps to control budworms, to limit their degree of damage.