Thressa daiyunshana, Liu, Xiao-Yan, Yang, Ding & Nartshuk, Emilia P., 2011

Liu, Xiao-Yan, Yang, Ding & Nartshuk, Emilia P., 2011, Species of the genus Thressa Walker, 1860 from China (Diptera, Chloropidae), ZooKeys 129, pp. 29-48 : 33-35

Thressa daiyunshana sp. n. Figs 1219

Diagnosis.

Thoracic pleuron blackish brown except for posterodorsal portion of katepisternum with a triangular yellowish brown spot; anterodorsal portion of katepimeron with a triangular yellow spot. Cercus triangular in ventral view. Pregonite about as long as postgonite.

Description.

Male. Body length2.9 mm, wing length2.2 mm.

Head (Fig. 12) black without microtomentum, about 0.8 times as long as high, wider than thorax; face sometimes concave in lateral view, bright brown with a yellow medial stripe more or less on dorsal 1/2; epistoma yellow; frons black, about as long as wide, projecting only slightly in front of eye, almost entirely occupied by broad ocellar triangle; gena narrowed, about 1/10 times as high as postpedicel; vibrissal angle obtuse; parafacial black, linear; postgena black; clypeus light black. Ocellar triangle very large and broad, smooth, black, shiny metallic blue, reaching to anterior margin of frons with broad apex; ocellar tubercle black. Occiput black. Cephalic setae and setulae black, weakly developed; if extremely short, in 1 row on the surface of the triangle; orb very minute, upright; oc subequal to orb; pvt small hair-like, upright, convergent; vte shorter than pvt and vti indistinct. Antenna darkish brown with thick grayish microtomentum, but pedicel with yellow ventral surface, postpedicel yellow at basoventral portion; postpedicel 2 times as long as wide, parallel-sided; arista pectinate, with 5 branches dorsally and 4 ventrally, apically with some short setulae, black except for basal segment yellow. Proboscis yellow with yellowish setulae and palpus black with black setulae.

Thorax (Figs 13, 14) shiny black without microtomentum, with granulated microsculpture, evenly covered with short setulae. Scutum strongly convex, almost as long as wide. Thoracic pleuron blackish brown except for posterodorsal portion of katepisternum with a triangular yellowish brown spot; anterodorsal portion of katepimeron with a triangular yellow spot. Scutellum about 0.5 times as long as wide; ap sc short, distinctly shorter than scutellum. Setae and setulae on thorax black. Legs yellow except for basal fore coxae, mid coxae, tarsomeres 4-5 black. Setulae on legs yellow, but apical portion of tarsi with some brown setulae. Tibial organ distinct, oblong. Wing (Fig. 15) about 2.9 times as long as wide, hyaline with a brown spot near wing apex, costal cell somewhat tinged with brown; veins brown. Relative lengths of 2nd: 3rd: 4th costal sections = 5: 2.5: 1; discal cell narrow and long; crossveins r-m and m-m not approximate, r-m at basal 1/3 of discal cell. Halter pale yellow on knob, brown on stem.

Abdomen shiny black except for distal 1/3 of tergite 3 and tergite 4 medially yellow, tergite 5 entirely yellow; venter yellow. Setulae on abdomen brown. Male genitalia (Figs 16-19): Epandrium short tubular, weakly sclerotized, yellow with long yellow setulae; surstylus basally broad with short spinous setulae, distally narrowed, attached to epandrium anteroventrally. Cercus triangular in ventral view. Gonites arranged in a row; postgonite slightly incurved distally with pointed apex, basally gradually narrowed, with some sensory setulae; pregonite about as long as postgonite, basally broad and round, distally narrowed; basiphallus longer than wide, cylindrical; distiphallus cylindrical, longer than basiphallus, beyond lower margin of hypandrium, largely membranous but weakly sclerotized on apex; phallapodeme long, extended near base of basiphallus, with basal stalk broad in lateral view. Hypandrium narrow.

Female. Unknown.

Type material.

Holotype ♂, Fujian: Dehua, Daiyunshan (25°47'N, 118°15'E, 720m), 11. VII. 2010, Xiaoyan Liu. Male type specimen was stored in 75% ethanol.

Distribution.

China: Fujian.

Remarks.

The new species is somewhat similar to Thressa apicalis (de Meijere) in the wing with a brown spot near the wing apex and the abdomen largely yellow. But it can be separated from the latter by the posterodorsal portion of the katepisternum with a triangular yellowish brown spot; the anterodorsal portion of the katepimeron with a triangular yellow spot; the legs yellow except for the basal fore coxae, mid coxae black. In Thressa apicalis , the dorsal portion of the katepisternum has one elongated yellow spot; the legs are yellow except the basal fore coxae black ( de Meijere 1910; Nartshuk 1993).

Etymology.

The species isnamed after the type locality Daiyunshan.