Afrotropical Culicoides (Diptera: Ceratopogonidae) : description of the hitherto unknown male of C. walkeri Boorman, 1979 from South Africa

Abstract

The genus Culicoides Latreille is represented by 160 described species in the Afrotropical Region; of these, approximately 10 % are plain-wing species, the wing lacking a distinctive pattern of pale and dark spots. This plain-wing sector includes C. walkeri Boorman which, till now, has been known only in the female, based on nine specimens fromKenya. The hitherto unknown male of C. walkeri is described here (and the female redescribed) based on material collected in South Africa since 1970. Culicoides walkeri can be distinguished from other plain-wing species in its pale ochreous colour, the robust shape of the male genitalia, and the sensilla coeloconica distribution which, uniquely, is the same in both sexes (occurring on flagellomeres 1–12). Though the feeding habits of C. walkeri are not known, its greatly inflated third palpal segment and the copious number of sensilla found on the flagellum, indicate it to be ornithophilic. Culicoides walkeri would appear to be confined to the frost-free savannas of the eastern length of Africa, from the equator southwards; its limited distribution in South Africa is mapped and shows that this uncommon species is confined to the Central Bushveld, the Lowveld and the Mopane bioregions. We propose that C. walkeri remain unplaced to subgenus.