Centorisoma shaanxiensis Liu & Yang, 2012, sp. n.

Centorisoma shaanxiensis sp. n.

Figs 5, 10, 15, 35–41

Diagnosis. Gena broad, about 0.5 times as wide as postpedicel. Postpedicel about 2.5 times as long as its basal breadth. Legs yellow except fore tibia and tarsus brown, basal portion of fore tibia yellow. Cercus rather large, nearly square. Postgonite without minute serrations on inner margin and far produced beyond basiphallus.

Description. Male. Body length 2.8–3.1 mm, wing length 2.2–2.3 mm.

Head brown with grayish microtomentum, about 0.9 times as long as high, 1.1 times as wide as thorax; face yellow except middle 3/4 with a large trapezoidal spot, somewhat concave in lateral view, facial carina indistinct; frons brownish yellow, anterior 1/3 yellow, slightly longer than wide, projecting only slightly in front of eye; gena broad, about 0.5 times as wide as postpedicel, anterior part yellow with lower margin brown; parafacial narrowed. Ocellar triangle blackish brown, smooth, shiny, reaching to anterior 0.9 of frons, with pointed apex; ocellar tubercle light brown. Cephalic setae and setulae black; oc and pvt hair-like, oc as long as pvt; vte and vti developed, vte slightly longer than vti. Antenna (Figs. 15) yellowish brown with thick microtomentum, but basal portion of pedicel brown, distal 2/3 of postpedicel black; postpedicel about 2.5 times as long as its basal breadth, basal 1/3 weakly concave; arista white except basal segment yellow, with short pale yellow setulae. Proboscis yellow with yellow setulae; palpus brown with brown setulae.

Thorax black with microtomentum, evenly covered with short setulae. Scutum with granulated microsculpture, about 1.1 times as long as wide. Thoracic pleuron shiny brown without microtomentum except for anteroventral portion of anepisternum and anepimeron, ventral 2/3 of katepisternum and ventral 1/2 of katepimeron black. Scutellum about 0.6 times as long as wide; ap sc short, distinctly shorter than scutellum. Setae and setulae on thorax black; npl 1+2, a npl hair-like, p npl developed, a npl subequal to p npl; a pa developed, p pa hair-like, a pa about 1.2 times as long as p pa; 1 dc, hair-like, as long as a pa. Legs yellow except fore tibia and tarsus brown, basal portion of fore tibia yellow. Setulae on legs brown. Mid tibia with a distinct black subapical spur longer than diameter of tibia. Tibial organ oblong. Wing (Fig. 10) about 2.7 times as long as wide, hyaline; veins brown. Relative lengths of 2nd: 3rd: 4th costal sections = 10: 7: 4; crossveins r-m and m-m not approximate, r-m at basal 0.55 of discal cell. Halter pale yellow.

Abdomen shiny brown except for basal portion of tergite 1 yellow; venter yellow. Setulae on abdomen brown.

Male genitalia (Figs. 35–38): Epandrium brown with many setulae; surstylus horizontally articulated with epandrium, strongly narrowed at apex. Cercus rather large, nearly square, articulated with distinct inner surstylar plate. Gonites arranged in a row, with a distinct demarcation at middle; postgonite simple, and gradually narrowed distally, far produced beyond basiphallus; basiphallus short; phallapodeme long, extended to base of basiphallus, with basal stalk broad in lateral view. Hypandrium broad.

Female. Body length 3.0 mm, wing length 2.3 mm.

Female genitalia (Figs. 39–41): Tergite 9 semicircular, distinctly wider than long, with 2 long setae; sternite 9 long, apically round with long stout setae. Cercus short and stout with some long setae.

Type material. Holotype 3, CHINA: Shaanxi: Zhouzhi, 16. VII. 2010, Tingting Zhang. Paratypes 1 3, 3 Ƥ, same data as holotype. All type specimens were stored in 75% ethanol.

Distribution. China: Shaanxi.

Remarks. The new species is somewhat similar to C. arsenjevi Nartshuk in the following aspects: gena yellow except posterior 1/2 black; postpedicel elongate, about 2.5 times as long as its basal wide; cercus well developed, apical margin nearly flat. But it can be separated from the latter by the legs yellow except the fore tibia and tarsus brown, the gonites with a distinct demarcation at middle, and the postgonite without minute serrations on inner margin near the basiphallus. In C. arsenjevi, the legs are entirely yellow; the gonites are indistinctly divided into two parts, the postgonite bearing the minute serrations on the inner margin near the basiphallus (Nartshuk 1965, 2005).

Etymology. The species is named after the type locality Shaanxi.