Centorisoma pentagonium, Liu, Xiaoyan & Yang, Ding, 2014

Liu, Xiaoyan & Yang, Ding, 2014, Five new species of Centorisoma Becker from China, with an updated key to world species (Diptera, Chloropidae), Zootaxa 3821 (1), pp. 101-115 : 110-112

Centorisoma pentagonium sp. n.

Figs 4 , 27–30

Diagnosis. Gena 0.5 times as wide as postpedicel. Postpedicel 1.5 times as long as its basal breadth. Legs entirely yellow. Cercus rather large, pentagonal, with a small concavity on ventral margin. Postgonite with minute serrations on inner margin, not produced beyond basiphallus.

Description. Male. Body length 3.8 mm, wing length 2.8 mm.

Head brown without microtomentum, 0.9 times as long as high, 1.1 times as wide as thorax; face yellow, somewhat concave in lateral view, facial carina indistinct; frons yellow, 0.9 times as long as wide, projecting only slightly in front of eye; gena broad, 0.5 times as wide as postpedicel, anteriorly yellow with lower margin brown; parafacial narrow. Ocellar triangle smooth, shiny, yellowish brown with a rhombic black spot on median area in front of ocelli, reaching to anterior 0.9 of frons, with pointed apex; ocellar tubercle light brown. Cephalic setae and setulae black; oc and poc hair-like, oc as long as poc; vte and vti developed, vte slightly longer than vti. Antenna yellowish brown with thick grayish microtomentum except ventral 1/3 of postpedicel yellow; postpedicel 1.5 times as long as its basal breadth, basal 1/2 weakly concave on dorsal margin; arista white except basal segment yellow, with short pale yellow setulae. Proboscis and palpus yellow with yellow setulae.

Thorax brown with microtomentum, evenly covered with short setulae. Scutum with granulated microsculpture, 1.1 times as long as wide. Thoracic pleuron shiny brown without microtomentum except for anteroventral portion of anepisternum, ventral 2/3 of katepisternum and ventral 1/2 of katepimeron black, dorsodistal portion of katepisternum yellow. Scutellum 0.7 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 2 times as long as p pa; 1 dc, hair-like, as long as a pa. Legs entirely yellow. Setulae on legs yellow except for apical portion of tarsi with some brown setulae. Mid tibia with a distinct black subapical spur slightly longer than diameter of tibia. Tibial organ oblong, narrow. Wing 2.5 times as long as wide, hyaline; veins brown. Relative lengths of 2nd: 3rd: 4th costal sections = 2.5: 1.7: 1; 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 tergites 1–3 yellowish brown, basal portion of tergite 1 yellow; 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, slightly short. Cercus rather large, pentagonal, with a small concavity on ventral margin, articulated with distinct inner surstylar plate. Gonites arranged in a row, with a distinct demarcation at middle; postgonite with minute serrations on inner margin, narrowed distally, not produced beyond basiphallus; basiphallus short; phallapodeme long, extended near base of basiphallus, with basal stalk broad in lateral view. Hypandrium broad.

Female. Unknown.

Type material. Holotype ♂, CHINA: Beijing: Yanqing, Songshan, 15. VII. 2003, Hui Dong. Paratype 1 ♂, Ningxia: Liupan Mountain, Qiuqianjia, 7. VII. 2008, Jingxian Liu.

Distribution. China: Ningxia, Beijing.

Remarks. The new species is somewhat similar to C. koreanum Nartshuk in the following aspects: gena 0.5 times as wide as postpedicel; legs entirely yellow. It can be separated from the latter by the following features: postpedicel yellowish brown except ventral 1/3 yellow, 1.5 times as long as its basal breadth; cercus large, pentagonal. In C. koreanum , the postpedicel is yellow, slightly darkened apically, 2 times as long as its basal breadth; the cercus is developed, trapezoidal ( Nartshuk 2005).

Etymology. The specific name is from the Latin pentagonius (“pentagonal”), refers to the shape of the cercus.

Figures

FIGURE 4. Centorisoma pentagonium sp. n., male. body, lateral view. Scale bar = 0.5 mm.

FIGURES 27 – 30. Centorisoma pentagonium 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.