Divergence of sex comb phenotypes in the Drosophila fima species group and radiation on Afrotropical Ficus, including five new species from East Africa and Madagascar (Diptera: Drosophilidae)

The Afrotropical Drosophila fima species group is unique with regard to male terminalia morphology and functioning, tarsal structure, sex comb diversity, and to ecology. Five new species, all belonging to the dyula complex on the basis of male terminalia, are described here. Four of them from East Africa provide the usual, albeit remarkable tarsal pattern of the so-called 'tarsus-modified' species, namely D. longicrinis, D. pilacrinis, D. stenotrichala and D. trichala. But the fifth new species from Madagascar and the Eastern Arc mountains of Tanzania, D. inopinata, provides a new combination of traits unexpected in the fima group, that is male terminalia typical of the dyula complex but lacking both tarsal modification and sex combs which were previously thought to characterize also the complex. The co-occurrence of such contrasted tarsal patterns within a 'clade' of closely related species may help understanding how rapidly the sex comb phenotype of males may change. It is argued that the diversity of sex comb phenotypes is related to the adaptive radiation of the fima group species on Ficus; and that having different sex comb features may be a way for species packing to occur.