We know this particular moth is a male because the females have no wings! Vancouver Loopers are found from northwestern British Columbia south to central California, and eastward to the nearer slopes of the Rocky Mountains. They may have been introduced on Vancouver Island from European nursery stock and may not be different from the European Erannis defoliaria, also known as the Mottled Umber.
Adults emerge in late September and October in our area, with the mated females laying close to 150 eggs in small scattered clusters concealed on the bark and twigs of a host tree. They overwinter there and hatch after leaf buds have opened, usually during May or June. Larvae feed on birch, willow, maple, oak, alder, aspen, and other hardwoods and sometimes severely defoliate them. They also enjoy western hemlock and western white pine. Viral disease and parasitism by tachinid flies contribute to the control of this species.
Size: Wingspan around 40 mm
Photo by: Kristi DuBois on 10/3/21 in Missoula, MT