The fall cankerworm, Alsophila pometaria (Harr.), and the winter moth, Operophtera brumata (Linn.), both feed to a great extent on the same tree species and prefer apple, Malus spp., red oak, Quercus rubra L., basswood, Tilia spp., white elm, Ulmus americana L., and Norway maple, Acer platanoides L. They also have similar life-histories and habits (Smith 1950 and 1953). Both lay their eggs on the trees in the fall and overwinter in this stage. The eggs hatch about the same time and the larvae of (both species mature about the third week in June. They drop to the ground and form cocoons at a depth of about an inch. The adults emerge about the same time, commencing usually during the last week in October and continuing until early December or until the ground freezes.