Gypsy Moth (Lymantria dispar) females are flightless moths which lay eggs on the bark of trees. The egg masses are protected from winter weather by wooly matts that are easily spotted during winter inspections. Larval emergence generally occurs in early May.
The furry caterpillars start out very small, but grow to 1-2 inches in length before pupation. They are distinguished by rows of blue and red dots.
Large populations of Gypsy Moth larvae can defoliate even large established trees. Many tree species can become infested, but evergreen trees such as spruce are severely impacted and can be killed in a single season.
Monitor trees for their telltale matts and the presence of live larvae that may be seen travelling up and down tree trunks or chewing holes in the foliage. If the infestation is significant, an application of a registered pesticide can be made by injection or spray.