Relationships within the melanogaster species subgroup of the genus Drosophila (Sophophora)

The polytene chromosomes of two new species of Drosophila, D. sechellia and D. orena, both members of the melanogaster species subgroup, are described. The chromosomes of D. sechellia, a species endemic to certain islands in the Seychelles, are homosequential with those of D. simulans and D. mauritiana. The chromosomes of D. orena, a species from the mountains of west Africa, are very similar to those of D. erecta. We discuss the interrelationships of the eight known species of the melanogaster species subgroup, based upon an analysis of their chromosome banding patterns.