Natural Hybridization between a Sympatric Pair of Hawaiian Drosophila

Abstract

Natural interspecific hybrids between 2 closely related spp. of Hawaiian [USA] Drosophila, i.e., D. heteroneura and D. silvestris, were collected from the Kahuku Ranch area on the island of Hawaii. Despite full fertility of both sexes of these hybrid specimens, hybridization is apparently not extensive. Investigations are continuing of the degree of introgression between these 2 spp. and of environmental factors which might contribute to the breakdown of isolating mechanisms.