Both males and females have fully formed wings and look similar. Wings highly variable in coloration: light or dark gray, brownish, or black.
This is one of the largest geometrids in North America, and has a very stocky body and long wings. The wing shape and position is very distinctive, giving the moth an unmistakable outline. Wings are almost never folded over the body.
Distribution pattern: Northern.
The subspecies B. betularia cognataria is restricted to North America. Europe has subspecies B. betularia betularia.
Biston betularia cognataria
Biston betularia contrasta
Albu & Metzler 2004
Reilly pers obs
These moths emerge in summer.
This moth was made famous by Kettlewell's natural selection experiments (Kettlewell 1955, 1956).
Generalist. Feeds on deciduous trees and shrubs including: Acer, Alnus, Amelanchier, Betula, Larix, Malus, Prunus, Quercus, Rhus, Ribes, Aster, etc (Tietz 1972).
Albu & Metzler 2004
Covell CV. 1984. A field guide to the moths of Eastern North America. Houghton Mifflin Company: Boston. 496 pp.
Kettlewell HBD. 1955. Selection experiments on industrial melanism in the Lepidoptera. Heredity 9: 323-342.
Kettlewell HBD. 1956. Further selection experiments on industrial melanism in the Lepidoptera. Heredity 10: 287-301.
McGuffin WC. 1977. Guide to the Geometridae of Canada (Lepidoptera) II. Subfamily Ennominae. 2. Memoirs of the Entomological Society of Canada 101: 1-125.
Morris RF. 1980. Butterflies and moths of Newfoundland and Labrador: The macrolepidoptera. Agriculture Canada Publication 1691. 407pp.
Reilly JR. Personal observation.
Rindge FH. 1975. A revision of the new world Bistonini (Lepidoptera Geometridae). Bulletin of the American Museum of Natural History 156(2): 71-155.
Skinner H. 1921. Moths collected at Hot Springs, Virginia (Lepid.). Entomological News 32(3): 65-71.
Stein KJ. 1993. Moth records from Burkes Garden, Virginia. Banisteria 2: 14-17.
Tietz HM. 1972. An index to the described life histories, early stages and hosts of the macrolepidoptera of the continental United States and Canada. A.C. Allyn: Sarasota, FL. 1041 pp.