Male. Head black in ground color, gena reddish brown below eye, with grayish white pruinosity; frontal vitta black, lunule pale brown; antenna black; arista brown, paler on aristomere 3; palpus dark brown to black, rarely dark yellowish. Vertex 1/9-1/11 head width; frontal vitta widened anteriorly, about twice as wide as fronto-orbital plate at middle; parafacial weakly widened below, 2.5-3 times as wide as flagellomere 1 at middle height; gena about 2/5 eye height; facial carina high and arched in lateral view, rather narrow and rounded on anterior surface; lower margin of face distinctly protruding forward. Inner vertical seta fine and short, about 2/5 eye height; outer vertical seta indistinct; ocellar seta strong, about 1.5 times as long as inner vertical seta; fronto-orbital plate bare outside row of frontal setae; 9-11 inclinate frontal setae; parafacial bare; vibrissa inserted slightly above level of lower margin of face; occiput with 2-3 rows of black hairs behind postocular setae. Antenna falling short of lower margin of face by about length of pedicel; base of antenna at the level of lower 1/4 of eye height; pedicel with a long seta that is slightly shorter than flagellomere 1; flagellomere 1 3.5-4 times as long as wide; total width of arista including plumosity about twice as wide as flagellomere 1.Palpus subequal in length to antenna; prementum 0.7-0.8 times as long as eye height. Thorax black in ground color, with grayish white pruinosity; dorsum with 3 black longitudinal vittae, median vitta broad, about 1.5 times as wide as outer vitta, extending to posterior 1/3 of postsutural scutum, outer vitta extending to posterior 1/4; scutellum with grayish pruinosity, darkened at base. Postpronotal lobe with 4-5 setae; 1-2+2 ac; 3+3-4 dc, if 4 postsutural setae present, then 2nd seta fine; 0+2 ia; 3 sa; scutellum with basal seta about 2.5 times as long as scutellum and subequal in length to subapical seta, apical scutellar seta rather fine, slightly shorter than twice as long as scutellum; discal seta suberect, slightly longer than scutellum. Wing hyaline, evenly and weakly tinged with pale brown; tegula black; basicosta reddish yellow; lower calypter dull yellowish white. Costal spine absent; relative length of second, third and fourth sections of costa approximately as 1:2:1; vein M from dm-cu crossvein to its bend about 3 times as long as distance between the bend and wing margin. Legs black; pulvilli yellowish. Fore tibia with a row of 4-5 fine ad on basal 3/5 and 2 submedian p; mid tibia with 1-2 ad (usually 1), 3-4 pd and 1 v; hind tibia with a row of 4-8 irregular ad, 2-3 pd and 2 v, apical pv about 1/ 2 of av length. Abdomen long ovate in shape, black in ground color, with grayish white pruinosity, the pruinosity with tessellated appearance and brownish on median portion of each tergite. Syntergite 1+2 excavated only on basal 1/2. Hairs on abdominal dorsum long and rather sparse, erect and strong on lateral portion of tergites 3 and 4, syntergite 1+2 with 2 strong erect median marginal and 1 long and strong lateral marginal setae, 2-3 additional long decumbent setae present on each side; tergite 3 with 2 median marginal, 2 median discal and 1-2 lateral marginal setae, or with a complete row of marginal and fine and weak decumbent discal setae; tergite 4 with 2 or irregular discal setae and a row of marginal setae; discal setae on tergites 3 and 4 arranged on posterior portion of each tergite and sometimes decumbent, rarely absent; tergite 5 with rows of strong marginal and discal setae. Male terminalia. Distal half of cerci distinctly narrowed, pointed apically; surstylus wide and extending beyond cerci, and narrowed apically in dorsal view and bluntly rounded at apex in lateral view; pregonite long and bent posteriorly; postgonite slightly shorter than basiphallus; distiphallus slender, membranous apical part about 2.5 times as long as sclerotized basal part; aedeagal apodeme slender, pointed apically. Female. Vertex 1/3-2/5 head width; frontal vitta about twice as wide as fronto-orbital plate at middle; gena 0.56-0.64 eye height; inner vertical seta strong, about 1/2 eye height; outer vertical seta short but strong, about 1/2 as long as inner vertical seta; 1 outwardly directed prevertical seta, subequal in length to outer vertical seta; 2 strong and subequally long proclinate orbital setae, almost as long as ocellar seta; 6-8 inclinate frontal setae; ocellar seta 3/4 as long as inner vertical seta. Mid tibia always with 1 ad; hind tibia with 3-4 pd; claw and pulvillus shorter than fifth tarsomere. Abdomen ovate, with rather thin grayish white pruinosity, posterolateral portion of tergites 3 and 4 black; hairs shorter than in male and recumbent except on lateral portion; syntergite 1+2 rarely lacking median marginal seta; median discal seta absent on tergites 3 and 4.