Madachironomus, a new genus of tribe Pseudochironomini (Diptera: Chironomidae, Chironominae) from Madagascar

Madachironomus gen. n. is described based on male and female imagines collected at two watersheds in Madagascar. Two species are included, M. lakazana sp. n. from Lakazana River, Antananarivo province and M. rongaronga sp. n. from Rongaronga River, Toamasina province. The adults have a black comb on the apex of the fore tibia, similar to the combs on mid- and hind tibiae, thus placing the new genus in the tribe Pseudochironomini Saether. The male has a strong, moderately long, nearly parallel-sided anal point with broadly rounded apex, without microtrichia except at base, and a digitiform, apically split median volsella with strong brush-like setae, projecting medially. The female sternite VIII has a very dense posteromedial to posterolateral field of setae, the gonocoxapodeme VIII is nearly straight, the gonapophysis VIII has closely adjacent, indistinctly separable lobes; the ovoid seminal capsules have nearly straight spermathecal ducts and the labia have internal apodemes and spinose chaetulae on dorsomedial surfaces.