Cryptic moths: effects on background selections of painting the circumocular scales.

A dark moth (Catocala antinympha) and a light moth (Campaea perlata) rested on appropriate backgrounds in an experimental apparatus allowing a choice between black and white backgrounds. The selections remained unchanged when the circumocular scales of the moths were painted either black or white. These results suggest that selections of background by cryptic moths, with respect to background reflectance, are genetically fixed. Background selections by melanic forms in various species are interpreted in the light of this conclusion.