Dicraeus curvus, Liu & Yang & Nartshuk, 2019

Liu, Xiaoyan, Yang, Ding & Nartshuk, Emilia P., 2019, New species and records of Dicraeus Loew, 1873 from China (Diptera: Chloropidae), Zootaxa 4554 (2), pp. 351-370 : 355-357

Dicraeus curvus sp. nov.

Figs 2 , 16–19

Diagnosis. Gena 0.8 times as wide as first flagellomere. Ocellar triangle reaching anterior 2/3 of frons. Scutum yellow with 5 longitudinal stripes. Scutellum yellow. Legs yellow except for fore femur brownish on anterior surface, all tarsomeres 5 brown. Surstylus broad basally, with 3 spinous setae, suddenly narrowed at middle and curved. Mesolobus (fused cerci) long, 2 times as long as surstylus, bent to venter of epandrium.

Description. Male ( Fig. 2 ). Body length 2.0 mm, wing length 1.8 mm.

Head yellow, 1.1 times as wide as thorax, 0.7 times as long as high in profile, face somewhat concave in lateral view, facial carina indistinct; frons as long as wide, projecting slightly in front of eye; gena broad, about 0.8 times as wide as first flagellomere, with few black setulae on ventral margin; parafacial indistinct; clypeus light brown; vibrissal angle obtuse. Ocellar triangle smooth, shiny, reaching anterior 2/3 of frons, with pointed apex; ocellar tubercle black. Occiput black. Cephalic setae and setulae black. Antenna yellow with thick grey pruinescence except for basodorsal portion of first flagellomere brown; first flagellomere 0.9 times as long as wide; arista brown with short brown pubescence. Proboscis yellow with yellowish brown setulae; palpus yellow with black setulae.

Scutum as long as wide, largely brown except yellow laterally, with 5 longitudinal stripes, 3 central stripes blackish brown, nearly coalesced anteriorly, outer lateral stripes reddish yellow, short and narrow. Postpronotal lobe yellow with a brownish spot. Thoracic pleuron shiny yellow except for anteroventral portion of anepisternum, ventral 2/3 of katepisternum and posteroventral portion of meron brown; anteroventral margin of anepimeron yellowish brown. Scutellum yellow, 0.7 times as long as wide; apical scutellar seta longer than scutellum; subapical scutellar seta as long as scutellum. Postscutellum blackish brown. Setae and setulae on thorax black; notopleurals 1+2, anterior notopleural seta as long as posterior notopleural seta; anterior postalar seta as long as posterior postalar seta; 1 pair of dorsocentral setae developed, 2 times as long as anterior postalar setae. Legs yellow except fore femur brownish on anterior suface, all tarsomeres 5 brown. Mid tibia with a short black subapical spur, which is shorter than diameter of tibia. Tibial organ long and narrow. Setulae on legs brown. Wing 2.3 times as long as wide, hyaline; veins brown. Relative lengths of 2nd: 3rd: 4th costal sections = 6: 1.4: 1; r-m at basal 0.45 of discal medial cell. Halter pale yellow.

Abdomen brown except for tergites 1+2 yellow, with brown distal and lateral margins; tergite 5 yellow with a black medial spot; venter yellow. Setulae brown.

Male genitalia ( Figs. 16–19 ): Epandrium yellow with long brown setulae, height 1.3 times width in lateral view; surstylus slightly shorter than depth of epandrium in lateral view, basally broad with 3 spinous setae, suddenly narrowed at middle and curved. Mesolobus (fused cerci) long, 2 times as long as surstylus, bent to venter of epandrium. Pre- and postgonites short, postgonite round distally, with few sensilla; basiphallus longer than wide, cylindrical; phallapodeme sclerotized, long, with basal stalk broad in lateral view. Hypandrium closed, apically forming an arch.

Female. Unknown.

Type material. HOLOTYPE 6, CHINA, Yunnan, Xishuangbanna, Mengyang, Yexianggu , 17. IV. 2007, Wenliang Li Leg. (CAU). PARATYPE 1 6, same data as holotype ( CAU) (photo and abdomen dissected). All type specimens were stored in 75% ethanol .

Distribution. China (Yunnan).

Remarks. The new species is somewhat similar to D. ischaemi Kanmiya, 1971 , but can be separated from the latter by the following features: first flagellomere round dorsodistally; surstylus broad basally, with 3 spinous setae, suddenly narrowed at middle and curved; mesolobus (fused cerci) long, 2 times as long as surstylus, bent to venter of epandrium. In D. ischaemi , the first flagellomere has a dorsodistal angle; the surstylus is slender, slightly concave at middle, broadly round apically, and has 5 long thick setae; the cercus is slender, finger-like ( Kanmiya 1971).

Etymology. The specific name is from the Latin curvus (“curved”), referring to the shape of mesolobus.

Figures

FIGURES 1–5. Dicraeus species, habitus. 1 D. crassispinus sp. nov.; 2 D. curvus sp. nov.; 3 D. dentatus sp. nov.; 4 D. liupanshanensis sp. nov.; 5 D. minutidentatus sp. nov. Scale bar = 1 mm.

FIGURES 16–19. Dicraeus curvus sp. nov. male. 16 epandrium, posterior view; 17 epandrium, lateral view; 18 hypandrium and phallic complex, ventral view; 19 hypandrium and phallic complex, lateral view. Abbreviations: bas, basiphallus; cer, cercus; ep, epandrium; hyp, hypandrium; phal, phallapodeme; pog, postgonite; prg, pregonite; sur, surstylus. Scale bar = 0.1 mm.