This is a minor pest in most regions, though it has severely defoliated sugarbushes in Quebec on occasion. Significant tree mortality or crown dieback has not been associated with outbreaks.

Adults have a wingspan of 1.2 to 1.6 inches (30 to 40 mm). The front wings are ash-gray to brownish-gray with a while band along the leading edge. They often have a narrow dark brown, wavy stripe near the tips. The hind wings are whitish to light brown. When resting on tree bark, the moth resembles a bird dropping. The caterpillar is 1.4 to 1.8 inches (35 to 45 mm) long and is marked with a bright orange head and orange hump on top of a rear segment (Fig. 35). The basic body color is yellow-orange with nine longitudinal black stripes. The stripes occur in groups of three (two lateral groups and one along the back) and the body between the stripes in each group is gray. Eggs are deposited in clusters and young caterpillars are gregarious until nearly full grown when they become solitary. Newly emerged caterpillars have shiny black heads (Fig. 36).