Numerous characters have been suggested to separate this species from C. projecta, including position of the PM line, sharpness of the ST line, width of the head and eyes, color of the thorax front (Rindge 1972), antennae (McGuffin 1977), subtle wing tint (Forbes 1948), and whiteness of the median area (Covell 1984). In my experience, none of these characters seem to do a very reliable job. C. sublunaria does often seem to have more uniform light coloration in the median area, though projecta can be this way, too.
Note the white tuft of scales where the thorax meets the abdomen. This tuft is distinctive for this genus.
Distribution pattern: Eastern.
Reilly pers obs
McGuffin WC. 1977. Guide to the Geometridae of Canada (Lepidoptera) II. Subfamily Ennominae. 2. Memoirs of the Entomological Society of Canada 101: 1-125.
Rindge FH. 1972. A review of the North American moths of the genus Cleora (Lepidoptera: Geometridae). American Museum Novitates no. 2482. 15 pp.
Forbes WTM. 1948. Lepidoptera of New York and neighboring states: part II. Cornell University Agricultural Experiment Station memoir 274.
Covell CV. 1984. A field guide to the moths of Eastern North America. Houghton Mifflin Company: Boston. 496 pp.