The Afrotropical species of the genus Ommatius Wiedemann, 1821 (Diptera: Asilidae): longipennis and sinuatus species-groups

Two new, montane, Afrotropical species-groups of Ommatius are reported, including nine species. The O. longipennis group includes O. acornutus sp. n., O. carbonarius sp. n., O. curtus sp. n., O. cornutus sp. n., O. digitus sp. n., O. marginosus sp. n. and O. longipennis Lindner. Ommatius longipennis is redescribed, and the male is reported for the first time. The O. sinuatus species-group includes O. ornatus sp. n. and O. sinuatus sp. n. With the exception of O. ornatus from Cameroon, members of these groups occur in eastern Africa along the Rift Valley from Ethiopia in the north to eastern Zimbabwe in the south. Most species occupy a narrow range, and a few are known from the type locality only. The species-groups and species are diagnosed, described, and compared with similar species. Keys to the species, illustrations of their terminalia and the wings of longipennis and O. sinuatus, and brief comments on their distribution and biology are included.