Intersexes Dependent on a Maternal Effect in Hybrids Between Drosophila Repleta and D. Neorepleta.

Drosophila repleta Wollaston and D. neorepketa Patterson and Wheeler are closely similar species, the former widely distributed and the latter known from Guatemala. It was found by Dr. E. Novitski that these species occasionally cross, and that the F1 females sometimes give a few offspring when mated to repleta males (see Wharton 1942 and Sturtevant 1946). I have found a sex-linked recessive white-eyed mutant type in D. repleta (actually not quite white, but retaining only a slight tinge of color). At least 5000 neorepleta females have been crossed to white repleta males (in a few cases the repleta males carried singed, another sex-linked recessive, rather than white). These matings included at least 500 mass cultures, of which 74 produced hybrid offspring -- a total of 532 females and 635 males, all wild type for the sex -- linked mutant characters used. The males had very narrow testes, and were wholly sterile. The females were variable; most of them had bristles somewhat reduced in size ("minute"), and many of them had three anal plates instead of the usual two -- this last character suggesting intersexuality.