Male. Body length 5.0–5.5 mm. Head: Eye bare, lower posterior margin not concave; frons about one-third of head width; frontal vitta with grayish brown pruinosity, about three times as wide as fronto-orbital plate, frontal triangle gray, reaching front of frons; 3 pairs of frontal setae, the middle one minute, 1 pair of orbital setae; ocellar setae long, about as long as frontal width; fronto-orbital plate with grayish brown pruinosity, parafacial and gena with gray pruinosity, parafacial equal to or narrower than antennal width; antenna black, flagellomere 1 about 2.5 times as long as broad, the tip rounded, falling short of epistomal margin by half of its length; arista short haired, the longest hairs about 1.5 times as long as its basal diameter; genal height about one-fourth of eye height; dorsal part of occiput with hairs, both genal and postgenal hairs entirely black; proboscis light black, labella with two teeth on each side, and a large and blade-shaped tooth behind them; prementum about 3.5 times as long as broad; palpus yellow on basal part and brown on distal part, subequal in length to haustellum. Thorax. Ground colour black with gray pruinosity; scutum with five grayish brown vittae, the middle one reaching scutoscutellar suture and the most lateral pair indistinct, scutellum mostly with brown pruinosity, both apical and basal scutellar setae well developed, an irregular row of prst ac, two rows of hair-like post acr, dc 1+3, ial 0+1, notopleuron, anepimeron, meron and katepimeron all bare, 2 proepisternal setae, 2 proepimeral setae, 3 katepisternal setae which form a triangle, lower one nearer to anterior one and with 1–2 fine hairs between them, both anterior and posterior spiracles brown. Wing. Hyaline, veins brownish, basicosta brownish, costal spine absent, costa reaching the tip of M, R4+5 and M nearly parallel; calypters yellowish, upper one about 3 times as long as lower one; the former subequal in length to its fringes; halter yellow. Legs. Black except for trochanters and apex of femora; fore tibia with a median p; mid femur with row of av, only the median one long and strong, a row of long and strong pv on basal three-fifths, 1 ad and 2 pd preapicals, mid tibia with 1 ad, 1 pd; basal part of hind femur with 2–3 characteristic av, 1 median av, complete row of pv and middle ones strong, slender hair-like, hind tibia with 1 av, 1 ad, 1 d, 2 pd; tarsi shorter than tibiae, claws and pulvilli long and large. Abdomen. Long-oval, ground colour black with dark gray pruinescence, without distinct spots and vittae, discal and lateral setae strong and long; sternite 1 with fine hairs, sternite 5 in the middle part of the ventral surface and protruding, its lateral lobes with dense long setae; cerci and surstylus slender; cerci becoming thin toward distal part and apex slightly enlarged in posterior view. Female. Hind femur with 2 (1) strong av on basal one-third, 1 av on distal one-third, other characters as in the male.