Oligopogon hemistego, Londt, 2014

Londt, Jason G. H., 2014, A revision of Afrotropical Oligopogon Loew, 1847 (Diptera: Asilidae) with the description of eighteen new species, African Invertebrates 55 (2), pp. 269-269 : 289-290

Oligopogon hemistego sp. n.

Figs 2F, 8, 17–19

Etymology: From Greek hemi (half) and stego (cover). In reference to the fact that microtrichia cover about half of the wing surface.

Description:

Head: Dark red-brown to black, dull silver pruinose, black and white setose. Antenna: Dark red-brown. Segmental ratios: 1:1.1: 3.9:2.3 (scape, pedicel, postpedicel, style). Scape and pedicel of similar development, black setose. Postpedicel long, circular in cross-section, tapering distally. Style of similar diameter to distal end of postpedicel, equipped with long black setae projecting from all surfaces. Face, frons and vertex fine dull silver pruinose, mystax black, ocellar macrosetae black. Occiput silver pruinose except for two large subtriangular apruinose areas abutting dorsal eye margin and extending almost to cervical region (see Fig. 2F), pale yellow-white setose. Face to head width ratio in anterior view 1:4.3 (face much narrower than one eye). Proboscis dark red-brown, straight, white setose. Palpi minute, 2-segmented, white setose.

Thorax: Dark red-brown to black, extensively dull silver pruinose, black and white setose. Mesonotum: Pruinose except for the following large apruinose areas: postpronotal lobes, broad medial strip (not extending to anterior or posterior margins), large posterolateral areas that coalesce with median strip. 2 black npl (other macrosetae poorly developed), general setae red-brown. Scutellum dark red-brown, silver pruinose anteriorly, apruinose apically, fine dark red-brown setose (ca. 4 thin poorly differentiated apical macrosetae). Pleura fairly uniformly silver pruinose. Katatergal setae pale yellow-white. Legs: Coxae dark red-brown, silver pruinose, whitish setose. Trochanters dark red-brown, pale yellow-white setose. Femora dark red-brown (note: a few ♀ specimens have orange-brown femora and may be somewhat teneral), predominantly pale yellow-white setose (1 dorsodistal black macroseta). Tibiae and tarsi brown-orange, mixed red-brown and pale yellow setose. Wings: 6.3 × 1.6 mm (holotype). Veins brown (somewhat yellowish proximally). Membrane transparent, unstained, extensively microtrichose distally ( Fig. 8) (lacking microtrichia proximally – discal cell partly microtrichose).

Abdomen: Terga dark red-brown, largely apruinose except for silver pruinose lateral margins, white setose. Sterna dark red-brown, extensively silver pruinose except for lateral margins, white setose. ♂ terminalia ( Figs 17–19) brown-orange, ♀ terminalia red-brown.

Holotype: ANGOLA: 1♂ ‘ Angola (A17) / 15mls. N. Sa / de Bandeira [14°01'S 15°11'E], / c. 6500 ft. / 3.iii.1972 ’, ‘Southern / African Exp. / B.M. 1972-1’ ( BMNH).

Paratypes: ANGOLA: 1♀ ‘ Angola : 20mi. S. / Caconda [13°44'S 15°03'E], 1680m. / 8-xii-1966 / E.S. Ross & / K. Lorenzen’ ( CASC) ; 7♂ 12♀ same data as holotype ( BMNH, NMSA 1♂ 1♀) .

Distribution ( Table 1), phenology (Table 2) and biology: Known only from two localities in Angola. Collected in December and March. Habitat is probably woodland savanna.