The Drepanid family of moths are distinguished from all others due to their sense of hearing (which is why the family includes some groups that are dissimilar in appearance to the classic “hook-tipped” moth but related by this feature). The abdominal ears of drepanids are structurally unique compared to those of other Lepidoptera and other insects, by having an internal tympanal membrane, and auditory sensilla embedded within the membrane.
Also known as the Masked Birch Caterpillar in its larval stage, the arched hooktip is a species of Hooktip moth (Drepanidae) that is native to North America, where it occurs from Newfoundland to Vancouver Island, south to South Carolina to the east and California to the west. Adults are often on wing from mid-may through late-July. Juveniles are known to associate with and feed on Betula, Papyrifera, and Alnus spp.