Centorisoma helanshanensis, Liu, Xiaoyan & Yang, Ding, 2012

Liu, Xiaoyan & Yang, Ding, 2012, The genus Centorisoma Becker in China, with a key to world species (Diptera, Chloropidae), Zootaxa 3361, pp. 18-32 : 22-24

Centorisoma helanshanensis sp. n.

Figs 3 , 8 , 13 , 27–30

Diagnosis. Body yellow. Postpedicel about 1.5 times as long as its basal breadth. Scutum with 5 reddish brown longitudinal stripes. Cercus large, apically margin with a small concavity. Postgonite with minute serrations on inner margin and slightly produced beyond basiphallus.

Description. Male. Body length 2.8 mm, wing length 2.5 mm.

Head yellow without microtomentum, about 0.8 times as long as high, 1.1 times as wide as thorax; face somewhat concave in lateral view, facial carina indistinct; frons about 0.8 times as long as wide, projecting only slightly in front of eye; gena broad, about 0.5 times as wide as postpedicel; parafacial narrowed; clypeus light brown. Ocellar triangle yellowish brown except for two margins and distal portion darkish brown, smooth, shiny, reaching to anterior 3/4 of frons, with pointed apex; ocellar tubercle light brown. Occiput 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. 13 ) yellowish brown with thick grayish microtomentum, but ventral 1/3 of postpedicel yellow; postpedicel about 1.5 times as long as its basal breadth, nearly parallel; arista white except basal segment pale yellow, with short pale yellow setulae. Proboscis and palpus yellow with yellow setulae.

Thorax yellow with microtomentum, evenly covered with short setulae. Postpronotum with a small brown spot. Scutum about 1.1 times as long as wide, basal 3/4 brownish, with 5 reddish brown longitudinal stripes, the medial stripe slightly broad and extending to posterior 3/4 of scutum, basal 1/3 of inner lateral stripes narrow, outer lateral stripes short and narrow. Thoracic pleuron shiny without microtomentum except for paratergite, anteroventral margin of anepisternum, anteroventral portion of anepimeron, ventral 2/3 of katepisternum and ventral 1/2 of katepimeron brown. Postnotum black. Scutellum yellow except two sides brown, 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 about 0.7 times as long as p npl; a pa and p pa developed, a pa about as long as p pa; 1 dc developed, as long as a pa. Legs yellow except femora yellowish brown except distal portions yellow; middle 1/4 of fore and mid tibiae, middle 1/3 of hind tibia yellowish brown; fore tarsus, mid and hind tarsomere 5 yellowish brown. Setulae on legs brown. Mid tibia with a distinct black subapical spur nearly as long as diameter of tibia. Tibial organ oblong, narrow. Wing ( Fig. 8 ) about 2.5 times as long as wide, hyaline; veins brown. Relative lengths of 2nd: 3rd: 4th costal sections = 8: 5: 3; crossveins r-m and m-m not approximate, r-m at basal 0.6 of discal cell. Halter pale yellow on knob, brown on stem.

Abdomen shiny yellowish brown; venter yellow. Setulae on abdomen brown.

Male genitalia ( Figs. 27–30 ): Epandrium brown with many setulae; surstylus horizontally articulated with epandrium, strongly narrowed at apex, elongate. Cercus rather large with a small concavity on apical margin, articulated with distinct inner surstylar plate. Gonites arranged in a row, with a distinct demarcation at middle; postgonite gradually narrowed distally, slightly produced beyond basiphallus and bearing minute serrations on inner margin near basiphallus; basiphallus short; phallapodeme long, extended to base of basiphallus, with basal stalk broad in lateral view. Hypandrium broad.

Female. Unknown.

Type material. Holotype 3, CHINA: Inner Mongolia: Helanshan Mountain, Xiquegou, 1. VIII. 2010, Yan Li. Type specimen was stored in 75% ethanol.

Distribution. China: Inner Mongolia.

Remarks. The new species is somewhat similar to C. flavum Nartshuk in the body yellow, two margins and apical portion of the ocellar triangle brown and the longitudinal stripes on the scutum reddish brown. But it can be separated from the latter by the following features: legs yellow except femora yellowish brown except distal portions yellow, middle 1/4 of fore and mid tibiae and middle 1/3 of hind tibia yellowish brown, fore tarsus yellowish brown; cercus rather large, with a small concavity on apical margin; postgonite slightly produced beyond basiphallus. In C. flavum , the legs are yellow except the fore tibia and tarsus varying from brown to black; the cercus is very small, its apical margin without concavity; the postgonite is far produced beyond the basiphallus ( Nartshuk 1965, 2005).

Etymology. The species is named after the type locality Hanlanshan Mountain.

Figures

FIGURES 3. Centorisoma helanshanensis sp. n., =

FIGURES 6 – 10. wing. 6 Centorisoma divisum sp. n.; 7 Centorisoma gansuensis sp. n.; 8 Centorisoma helanshanensis sp. n.; 9 Centorisoma scutatum sp. n.; 10 Centorisoma shaanxiensis sp. n. Scale bar = 0.25 mm.

FIGURES 11 – 15. antenna. 11 Centorisoma divisum sp. n.; 12 Centorisoma gansuensis sp. n.; 13 Centorisoma helanshanensis sp. n.; 14 Centorisoma scutatum sp. n.; 15 Centorisoma shaanxiensis sp. n. Scale bar = 0.1 mm.

FIGURES 27 – 30. Centorisoma helanshanensis sp. n., male. 27 epandrium, posterior view; 28 epandrium, lateral view; 29 hypandrium and phallic complex, ventral view; 30 hypandrium and phallic complex, lateral view. Scale bar = 0.1 mm.