THE ERCEPEAE COMPLEX - NEW CASES OF INSULAR SPECIATION WITHIN THE DROSOPHILA-ANANASSAE SPECIES SUBGROUP (MELANOGASTER GROUP) AND DESCRIPTIONS OF 2 NEW SPECIES (DIPTERA, DROSOPHILIDAE)

Two new species of the Drosophila ananassae subgroup are described. D. comorensis Tsacas sp. n. and D. merina Tsacas sp. n. are endemic to t he Indian Ocean islands Comores and Madagascar, respectively. Comparis ons with 2 other species, also endemic to Indian Ocean islands and bel onging to the D. ananassae subgroup, D. earpiece Tsacas & David from L a Reunion and D. vallismaia Tsacas from Seychelles, lead to the defini tion of a 3rd complex, ercepeae, within this subgroup. Relationships a mong the 4 species of the ercepeae complex are based on morphological data (the only data available for D. comorensis), mitotic and polytene chromosome analyses, behavioral interactions, interspecific hybridiza tions, chemical analyses of cuticular hydrocarbons, and amylase polymo rphism. Within this complex, D. ercepeae and D. merina are distinguish ed from D. vallismaia and D. comorensis. AU characters show close affi nities between D. ercepeae and D. merina. The geographic distribution of the species of the 3 complexes of the D. ananassae subgroup is also discussed.