Atherigona (Atherigona) robertsi Deeming 1971

Atherigona (Atherigona) robertsi Deeming, 1971, okavango, ssp. nov. Figs 17–20 Etymology: The subspecific epithet okavango is a noun in apposition, named after the Okavango River in northern Namibia, adjacent to the type locality. Description: Male. Body length: ca 3.0 mm; wing length: 3.0 mm. All setae and setulae black with exception of yellow setae bordering truncate apex of palpus. Head: Colouration yellow, with heavily whitish pruinescence on parafacial, less heavily so on face and gena; parafacial immediately above gena at narrowest point, no wider than arista; fronto-orbital plate black, shiny throughout; frontal vitta infuscate, weakly suffused with yellow anteriorly; ocellar triangle and occiput black and weakly shiny, occiput with heavy grey pruinescence between postocular setal row and eye margin; palpus black in basal 1 / 2; antenna with scape black, pedicel ferruginous and postpedicel ferruginous with apical 1 / 2 infuscate; basal two articles of arista ferruginous, remaining articles brown; sclerites of proboscis dark brown. Thorax:Colouration black on scutum, scutellum, metanotum,katatergite, anepimeron,anatergite and prosternum; scutum bearing weak grey pruinescence, with faint brown fasciae along dorsocentral lines and medially; ventral 1 / 2 of metanotum shiny; postpronotal lobe and pleura immediately beneath it yellow, with yellow pruinescence; proepisternum with 1 long seta and short setula; proepimeron with minute setula only; ventral katepisternal seta inserted much closer to more posterior of 2 dorsal setae. Legs: Yellow; fore tibia with apical 1 / 2 and tarsomeres 1–4 black; fore femur with row of 4 strong anterodorsal setae in apical 1 / 2, preapical anteroventral seta strong, tarsus with middle segments bearing some longer anterodorsal setae; mid femur with strong posterodorsal seta; mid tibia with short posterior seta at mid length; hind femur with distinct row of anterodorsal setae, becoming longer towards apex; hind tibia with anterodorsal at 0.50, anteroventral at 0.66, posterodorsal at 0.68 and dorsal preapical at 0.90 of length; [tarsi of both hind legs missing]. Wing: Membrane yellowish hyaline, veins yellow, pale microtrichia absent from basal costal cell (bc) and basal medial cell (bm); calypters similar, with yellow rims and fringes; haltere yellow. Abdomen: Colouration yellow; tergites 3–5 with pair of small black roundly triangular maculae; tergites 2–4 with some conspicuously large lateral setae; hypopygial prominence (Figs 19, 20), knob-like, with dorsal surface pilose; trifoliate process (Figs 17, 18), black, with stem 3 × as long as lobes. Female: Unknown. Affinities. This new subspecies is very similar to the nominate subspecies A. robertsi Deeming, which has a very distinctive trifoliate process (Deeming 1971:149, fig. 21), known from East and West Africa. The above cited specimen from Katara was compared to material of the nominate subspecies from both subregions and was found to be morphologically identical, except the median lobe of the trifoliate process, which is markedly different, both in ventral and lateral views, thus warranting subspecific status. Type material examined: Holotype ♂, “ Namibia: RUNDU DIST. / Katara: Okavango R. / 17°48'56''S 18°53'38''E / 20–23.i.1998 / [A.H.] Kirk-Spriggs & [E.] Marais / malaise trap [printed] // Namibian National / Insect Collection / National Museum / P.O. Box 1203 / Windhoek, Namibia [printed; blue card] // HOLOTYPE ♂ / Atherigona (s. str.) / robertsi / okavango ssp. nov. / J.C. Deeming 2024 [printed; white card with red border]” (NMNW; type series #664). In good condition, micro-pinned and staged; dissected, male terminalia in micro-vial pinned beneath specimen.