Chromatopterum brevicercum, Liu & Nartshuk & Yang, 2017

Liu, Xiaoyan, Nartshuk, Emilia P. & Yang, Ding, 2017, Chromatopterum (Diptera, Chloropidae), a newly recorded genus from China, and description of two new species, Zootaxa 4306 (2), pp. 279-286 : 280-283

Chromatopterum brevicercum sp. nov.

Figs 1–9

Diagnosis. Ocellar triangle black, shiny, reaching anterior margin of frons. Scutellum dark yellow. Femora yellow except for middle 1/2 of fore femur brown. Fuscous costal band restricted in cell R1 extending beyond apex of R4+5, apical spot separated by a narrow space from apex of costal band.

Description. Male ( Figs. 1–2 ). Body length 2.3 mm, wing length 1.9 mm.

Head yellow, 0.85 times as long as high in profile, 1.2 times as wide as thorax; face somewhat concave in lateral view, facial carina indistinct; frons as long as wide, projecting slightly in front of eye; gena narrow, black; parafacial indistinct; clypeus light black; vibrissal angle obtuse. Ocellar triangle black, smooth, shiny, reaching anterior margin of frons, with pointed apex; ocellar tubercle light brown. Postgena and occiput black. Cephalic setae and setulae black; ocellar seta procurved and convergent; postocellar seta upright and convergent, longer than ocellar seta; inner vertical seta as long as outer vertical seta. Antenna yellow except for basal portion of pedicel and distodorsal portion of first flagellomere yellowish brown, with thick grayish microtomentum; first flagellomere 1.3 times as long as wide; arista brown except for basal segment yellow, with short brown pubescence. Proboscis brown to yellow with yellow setulae; palpus black with black setulae.

Scutum almost as long as wide, brown in ground color with 5 black longitudinal stripes, 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 brown except for anteroventral portion of anepisternum; ventral 3/4 of katepisternum and posteroventral portion of katepimeron black. Postnotum black. Scutellum dark yellow, 0.5 times as long as wide; apical scutellar seta long, 2 times as long as scutellum; subapical scutellar seta as long as scutellum. Setae and setulae on thorax black except for lower margin of katepisternum with some yellow setulae; notopleurals 1+2, anterior notopleural seta hair-like, posterior notopleural setae developed, anterior notopleural seta 1.5 times as long as posterior notopleural seta; anterior postalar seta developed, posterior postalar seta hairlike, anterior postalar seta 1.5 times as long as posterior postalar seta; 1 pair of dorsocentral setae developed, 2 times as long as anterior postalar setae. Legs yellow except for fore coxa, basal portions of mid and hind coxae, middle 1/2 of fore femur brown. Tibial organ long and narrow. Setulae on legs brown. Wing 2.8 times as long as wide, hyaline; veins brown; fuscous costal band restricted in cell R1 extending beyond apex of R4+5 and conspicuously widened beyond apex of R2+3, widest over apex of R4+5, inner margin of apical section generally sharply defined, apical spot separated by a narrow space from apex of costal band. Relative lengths of 2nd: 3rd: 4th costal sections = 10: 7: 3; cross-veins r-m and dm-cu not approximated, r-m at basal 0.35 of discal medial cell. Halter pale yellow.

Abdomen shiny brown; venter yellow. Setulae black.

Male genitalia ( Figs. 3–6 ): Epandrium yellow with long yellow setulae, without a pair of band-shaped sclerites, but hyaline membrane present around the anus with some spinous setulae; surstylus basally broad with short spinous setulae, distally narrowed. Mesolobus long, 2 times as long as wide, ventral portion wide, with 2 pairs of setulae. Gonites arranged in a row; postgonite 1.2 times as long as pregonite, incurved distally with pointed apex, with some sensory setulae, basally pointed; pregonite basally broad and round, distally narrowed; basiphallus longer than wide, cylindrical; distiphallus cylindrical, membranous, extended to basal margin of pregonite; phallapodeme long, extended to base of basiphallus, with basal stalk broad in lateral view. Hypandrium narrow, without two basal rounded projections.

Female. Body length 1.9 mm, wing length 1.7 mm.

External characteristics similar to male except for hind coxa entirely yellow. Female genitalia ( Figs. 7–9 ): epiproct pentagonal, slightly longer than wide, with 2 long setae; hypoproct long, apically round with long stout setae. Cercus long and stout with some long setae.

Type material. HOLOTYPE Ƌ, CHINA: Hainan: Wuzhishan, Guanjingtai, Shuiman, 29. X. 2007, Coll. Ding Yang . PARATYPES 1 ♀, same data as holotype ; 2 ♀♀, Yunnan: Mengla, Yaoqu, Xiaopubu, 6. VIII. 2010, Coll. Wenliang Li ; 1 ♀, Mengla, Bubeng, Qingshuigou, 8. VIII. 2 0 10, Coll. Wenliang Li (in 75% alcohol, deposited in CAU).

Distribution. China (Hainan, Yunnan).

Remarks. The new species is somewhat similar to C. delicatum Becker , but can be separated from the latter by the following features: halter entirely pale yellow; scutellum dark yellow; apical spot separated by a narrow space from apex of costal band. In C. delicatum , the knob of halter is ivory white; the scutellum is entirely black; and the apical spot connects with the apex of the costal band ( Becker 1910).

Etymology. The specific name is from the Latin brevi- (“short”) and cercus (“cercus”), referring to the shape of mesolobus.

Figures

FIGURES 1 – 2. Chromatopterum brevicercum sp. nov. male. habitus, 1 dorsal view; 2 lateral view. Scale bar = 0.5 mm.

FIGURES 3 – 6. Chromatopterum brevicercum sp. nov. male. 3 epandrium, posterior view; 4 epandrium, lateral view; 5 hypandrium and phallic complex, ventral view; 6 hypandrium and phallic complex, lateral view. Scale bar = 0.1 mm.

FIGURES 7 – 9. Chromatopterum brevicercum sp. nov. female. 7 abdominal terminalia, dorsal view; 8 abdominal terminalia, lateral view; 9 abdominal terminalia, ventral view. Scale bar = 0.1 mm.