Wing homoeosis in Lepidoptera: A survey

Abstract

I analyzed 161 recorded and 3 unrecorded cases of wing homoeosis in Lepidoptera, using butterflies having gyanadromorphic wing mosaics as controls. The nature and distribution in various wing parts of homoeosis were subject to significant biases usually characteristic of taxon. The homoeotic conversion occurred between the forewing and hindwing or between the dorsal and ventral surfaces of a wing in either direction, the latter type of conversion being much rarer but singularly prevalent in some allied taxa of Lycaenidae. The extent of homoeotic alterations ranged from the whole wing to a few scales only, the commonest type being mosaics on a single wing surface with altered patterns of color scales. In or around intervenous space M 1–M 2 there seems to be a cryptic barrier that delimits the presumably clonal areas of forewing/hindwing homoeoses. I interpret such homoeoses as lepidopteran counterparts of the “bithorax”-group phenocopies in Drosophila, and dorsal/ventral homoeoses as an indication of the existence of dorsal/ventral compartments. I discuss the formation of ocellus pattern in Satyridae in relation to the boundaries of putative compartments in the wing.