Thorax polished black in both sexes; female abdomen partly yellow. Scutellum with three pairs of marginal setae. Legs mostly blackish, except coxae and trochanters yellow, and femora brownish yellow except apical portions of fore and mid femora brown and apical portion of hind femur brownish. Sense-organ of fore tibia with narrow hair brush pointed apically. Hypandrium distinctly longer than wide, with obtuse apex.

Male (Fig. 1). Body length 3.1–3.2 mm, wing length 2.8–2.9 mm.

Head black with gray pollinosity. Eyes contiguous on frons, brownish, with upper facets slightly enlarged; face linear. Setulae and setae on head black, posteroventral setulae dark yellow. Ocellar tubercle distinct with 2 long oc and 2 very short posterior setulae. Antenna black; pedicel with circlet of black subapical setulae; first flagellomere elliptical, 2.0 times longer than wide, minutely pubescent; arista long (2.7–2.8 times as long as first flagellomere), supra-apical, bare, one-segmented and black. Proboscis short, mostly brownish yellow, with black setulae; palpus black with black setulae and 2 thin black setae.

Thorax mostly polished black except postalar callus dark brownish yellow; mesonotum with narrow mid-lateral area and scutellum with gray pollinosity. Setulae on thorax blackish, setae weak and black; setulae on mesonotum sparse; humerus with 3–4 setulae, without h; 2 npl; acr and dc uniseriate and hair-like; 1 sa; 1 psa; 1 prsc; scutellum with short dense pubescence and 3 pairs of sc (apical pair distinctly longer than lateral pairs). Legs mostly blackish, except coxae and trochanters yellow, and femora brownish yellow except apical portions of fore and mid femora brown and apical portion of hind femur brownish. Setulae and setae on legs blackish, setae weak; coxae with yellow setulae and setae, hind femur with hair-like av slightly longer than femur thickness. Sense-organ of fore tibia with narrow hair brush pointed apically (Fig. 4). Hind tibia distinctly thickened apically; hind tarsomere 1 slightly thickened, slightly shorter than tarsomeres 2–5. Wing (Fig. 3) hyaline, tinged gray; stigma dark brown, about 1/4 as long as cell r₁; veins dark brown. Squama dark brown with dark brown setulae. Halter dark brown.

Abdomen slightly curved downward and polished blackish; venter with gray pollinosity. Setulae and setae on abdomen blackish; tergites 1–2 with dark yellow lateral setulae, sternites 1–2 with dark yellow setulae.

Male genitalia (Figs 5–9). Left and right epandrial lamellae fused basally by narrow band. Left epandrial lamella narrow in dorsal view; left surstylus finger-like, strongly curved inwards. Right epandrial lamella wide basally in dorsal view; right surstylus weakly curved inwards with acute apex; left and right cerci subequal in length and obtuse apically. Hypandrium distinctly longer than wide, with obtuse apex. Two branches of bifid appendage at tip of phallus equally long but unequally stout.

Female (Fig. 2). Body length 3.1–3.4 mm, wing length 3.6–3.7 mm. Similar to male, but abdomen distinctly swollen, tergites 2–5 yellow laterally and tergite 6 sometime yellow at antero-lateral portion. Legs dark yellow except coxae and trochanters yellow, fore tibia and tarsus blackish; mid and hind tibiae dark brownish yellow, tarsi dark brown except tarsomere 1 dark yellow and tarsomere 2 brownish.

Holotype: male, China: Shanxi Province, Yicheng, Yishan, Dahe, 2012.VII.24, Zhenghua Zhang (in 75% alcohol, deposited in CAU). Paratypes: 3 males, 4 females, same data as holotype (in 75% alcohol, deposited in CAU); 1 male, 1 female, China: Shanxi Province, Yicheng, Yishan, Dahe, 2012.VII.23, Chen Wang (in 75% alcohol, deposited in CAU).

China (Shanxi).

The new species is similar to the European species Ocydromia melanopleura, but may be distinguished from the latter by the scutellum with three pairs of distinct marginal setae (apical pair longest), right surstylus weakly curved inwards, and hypandrium obtuse apically. In Ocydromia melanopleura, the scutellum has only one pair of distinct marginal setae, the right surstylus is strongly curved inwards, and the hypandrium is truncated apically (Chvála, 1983).

The species is named after the type locality Shanxi.