[Interspecific hybridization in the Drosophila takahashii subspecies complex]

To elucidate the relationship between 6 species involved in the Drosophila takahashii complex, we analyzed the existence of interspecific hybridization, hybrids number with sex ratio, and the reproductive status of the hybrids of these species. We found that each of the 6 species formed hybrids with at least one other species. The most closed relationship among these species was confirmed to be between D. lutescens and D. trilutea, and D. prostipennis was rather isolated from the other 5 species. In ascending order D. takahashii showed a closed relation to D. lutescens, D. trilutea, and D. paralutea. It was shown that D. prostipennis and D. nepalensis form hybrids with D. paralutea and D. lutescens, respectively.