Dinera nigrisquama Zhang & Fu, 2012, sp. nov.

Dinera nigrisquama sp. nov.

(Figs. 5–6, 17–21)

Diagnosis. Small yellowish fly, 4 narrow dark brown longitudinal vittae on presutural scutum, 2 katepisternal setae, lower calypter dark brown, abdomen densely covered with yellowish pruinosity, without dark markings on tergites.

Description. Body length 7.0 mm.

Male. Head black in ground color, gena reddish brown, face, lower parafacial, genal dilation and occiput with dense yellowish pruinosity; frontal vitta black; lunula dark brown; antenna and palpus black. Frons narrowest in front of ocellar triangle, about 1/15 head width or less than the distance between inner margin of posterior ocelli; frontal vitta strongly widened anteriorly, linear at narrowest point; parafacial weakly widened below, about 2 times as wide as flagellomere 1 at middle height; genal height about 1/2 eye height; facial carina developed, high and protruding, arched in lateral view; lower margin of face protruding forward. Fronto-orbital plate and parafacial bare. Inner and outer vertical setae slender and hair-like, about 2/5 eye height; ocellar seta rather strong, 0.5–0.6 times eye height; 9–11 inclinate frontal setae, longest seta about as long as ocellar seta; vibrissa inserted slightly above lower margin of face. Antenna falling short of lower margin of face by length of flagellomere 1; flagellomere 1 2–2.5 times as long as pedicel, 1.5–2 times as long as width; pedicel with a long seta that is as long as pedicel and flagellomere 1 combined; arista including plumosity 1.5–2 times as wide as flagellomere 1. Prementum slen- der, 4–5 times as long as wide; palpus about as long as prementum.

Thorax black in ground color, with yellow pruinosity on dorsum and pleura; with 4 narrow black longitudinal vittae on dorsum, outer vitta narrower than distance between inner and outer vittae on presutural area. Postpronotal lobe and scutellum black in ground color. Prosternum about twice as long as wide. Postpronotal lobe with 4–5 setae, 3 strong basal setae nearly in a straight line; 2 presutural and 2 postsutural acrostichal setae; 2 presutural and 3 postsutural dorsocentral setae; 2 postsutural intra-alar setae; 3 supra-alar setae; 2 katepisternal setae; scutellum with a pair of discal setae, apical scutellar setae crossed and slightly longer than scutellum, shorter than subapical scutellar seta. Wings hyaline, pale brown; tegula dark brown; basicosta brownish yellow; lower calypter dark brownish. Costal spine absent; relative length of second, third and fourth costal sections approximately as 1:2:1; vein M from dm-cu crossvein to its bend about 2.5 times as long as distance between the bend and wing margin. Legs black, claws black, pulvilli pale yellowish. Claws and pulvilli equal in length to or slightly shorter than tarsomere 5. Fore tarsi distinctly longer than head height. Fore tibia with a row of short anterodorsal and 2 posterior setae; mid tibia with 1 anterodorsal, 2 posterodorsal and 1 posterior seta, without ventral seta; hind tibia with 3–5 anterodorsal, 3 posterodorsal and 2–3 ventral setae, and 2 preapical dorsal and 2 preapical ventral setae.

Abdomen long ovate, black in ground color, with dense yellow pruinosity on whole tergites. Syntergite 1+2 excavated 1/2 way to posterior margin, with 1 long hair-like lateral marginal seta, without median marginal setae; abdominal tergites with erect long hairs, without median discal setae; tergite 3 with 1 pair of strong median marginal and 2–3 pairs of long hair-like lateral marginal setae; tergites 4 and 5 each with a row of marginal setae. Sternite 5 nearly square, lateral lobe bluntly round; V-shaped median cleft deep and narrow. Male terminalia. Cerci wide at base and strongly narrowed on apical 1/ 2 in caudal view, slightly and evenly curved ventrally; surstylus bluntly rounded in lateral view; postgonite about as long as basiphallus; distiphallus long, apical membranous part 2–2.5 times as long as basal sclerotized part.

Type material. Holotype 3, CHINA, Yunnan: Baimaxueshan Mountain (28°41ʹN 99°00ʹE), 4250m, Deqin, 27.vii.2008, S.-C. Bai (SYNU). Paratype. CHINA, Yunnan: 1 male, Yakou, 4000 m, Daxueshan, Shangri-la (= Zhongdian), 21.viii.1981, X.-Z. Zhang (IZCAS).

Etymology. Specific epithet is taken from a diagnostic character of this species, the dark brown calypter.

Distribution. China (Yunnan).

Remarks. This species is very similar to D. maculosa Zhang & Shima (which has 3 wide dark longitudinal vittae on presutural scutum, syntergite 1+2 excavated 2/3–4/5 of the way to posterior margin, 3 katepisternal setae, and tergites 3 and 4 with a triangular black marking in male), but differs from it in having 4 narrow dark longitudinal vittae on presutural scutum, syntergite 1+2 excavated 1/2 way to posterior margin, 2 katepisternal setae, tergites 3 and 4 without a triangular black marking, and cerci narrowed apically in caudal view.