Subgenus Atherigona Rondani, 1856

Orthostylum Macquart, 1851b: 246 (273) (as genus). Type species: Orthostylum rufipes Macquart, 1851a [= Coenosia pulla Wiedemann, 1830], by original designation.

Atherigona Rondani, 1856: 97 (as genus). Type-species: Atherigona varia Meigen, 1826, by original designation. Atherigona (Atherigona) albistyla Deeming, 1971 .

Atherigona albistyla Deeming, 1971: 164, figs 81, 82; Deeming 1979: 40, figs 23–25; Deeming & Overman 1987: 117; Dike 2003: 219 (distribution); Muller & Mostovski 2018: 346, fig. 32.

Material examined: 1♂, Katima Mulilo District, Salambala campsite, 17°50'01''S, 24°36'09''E, 23.xii.2002, A.H. & M.K. Kirk-Spriggs, Malaise trap ; 1♂, West Caprivi Park, Kwando River: Susuwe, 17°45'37''S, 23°20'55''E, 28.ix– 02.x.1998, A . H. Kirk-Spriggs, Malaise trap, dry woodland (both NMNW) .

Remarks: Both specimens examined here agree with A. albistyla in the colour pattern of the stem of the trifoliate process, the apical 1 / 3 of which is white. Rather than having an entirely black antenna (as does the type series from Nigeria), however, the Susuwe specimen (cited above) has the pedicel ferruginous and the postpedicel basally yellow ventrally for 1 / 2 its length on both surfaces, whereas in the Salambala specimen (cited above), the pedicel is ferruginous and the postpedicel black. Examination of material from Burkina Faso, Ethiopia, Kenya, Nigeria and Uganda in NMWC demonstrates considerable variation in the dark markings on the abdominal tergites, those from higher elevations being more extensively dark. In three of seven males from Burkina Faso the pedicel is ferruginous and all possess a pair of very small black tergal maculae. With such variation in colour within the material available for study, one cannot dismiss from inclusion the specimen (from Susuwe), having a difference in one antennal segment from belonging to this species, especially as the male hypopygial prominence and trifoliate process are identical and it was collected far outside the known range. It would be prudent, however, to regard its identification as tentative.

Distribution: (Afrotropical): Burkina Faso, Kenya, Mali, Namibia *, Nigeria and Uganda.

Host-plant: Brachiaria xantholeuca (Hack.) Stapf ( Poaceae).