About Drepana arcuata Walker, 1855
Drepana arcuata, commonly known as the arched hooktip or masked birch caterpillar, is a moth species belonging to the family Drepanidae. This species was first formally described by Francis Walker in 1855. Its range extends from Newfoundland to Vancouver Island in Canada, and extends south to at least North Carolina, South Carolina, and California in the United States. The wingspan of adult Drepana arcuata measures between 24 and 40 millimetres, which equals 0.94 to 1.57 inches. Adult moths are active in flight from mid-May to late-July each year. In the northern part of its range, this species produces one generation per year. The caterpillar larvae of this species feed on Betula papyrifera and species from the genus Alnus, and they may use their host plant surfaces to communicate with other larvae. Larvae produce sound by shaking their bodies, drumming, scraping their mouthparts, or dragging specialized anal structures called "oars" against the surface of a leaf. Drepana arcuata larvae build shared communal silk shelters, and the sounds they produce may attract other larvae to join the shelter.
