Dicraeus minutidentatus, 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 : 362-364

Dicraeus minutidentatus sp. nov.

Figs 5 , 28–31

Diagnosis. Gena as wide as first flagellomere. Ocellar triangle reaching anterior 2/3 of frons. Scutum yellow with 3 longitudinal stripes, coalesced posteiorly. Legs yellow except for tarsomeres 5 brown. Surstylus broad distally, some thickened setae on inner side of lateral and distal portions. Cercus broad basally, distal 2/3 narrow, fingerlike, directed medioventrally. Postgonite bearing a minute serrulation on ventrodistal margin.

Description. Male ( Fig. 5 ). Body length 1.8–1.9 mm, wing length 1.7–1.8 mm.

Head yellow, 1.1 times as wide as thorax, 0.8 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, as wide as first flagellomere, with few brown setulae on ventral margin; parafacial indistinct; clypeus light yellow; vibrissal angle obtuse. Ocellar triangle yellow, smooth, shiny, reaching anterior 2/3 of frons, with pointed apex; ocellar tubercle yellowish brown. Occiput black. Cephalic setae and setulae black. Antenna yellow with thick grey pruinescence except for basodorsal margin of first flagellomere brown; first flagellomere as long as wide; arista brown with short brown pubescence. Proboscis yellow with yellow setulae; palpus yellow with black setulae.

Scutum 0.9 times as long as wide, yellow with 3 longitudinal reddish yellow stripes except for brownish lateral stripes basally, coalesced anteriorly. Thoracic pleuron shiny yellow except for anteroventral portion of anepisternum and posteroventral portion of meron brownish yellow. Scutellum yellow, 0.5 times as long as wide; apical scutellar seta 1.5 times as long as scutellum; subapical scutellar seta as long as scutellum. Postscutellum brown. Setae and setulae on thorax black; notopleurals 1+2, anterior notopleural seta as long as posterior notopleural seta; anterior postalar seta 3 times as long as posterior postalar seta; 1 pair of dorsocentral setae developed, as long as anterior postalar setae. Legs yellow except for 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 2.5 times as long as wide, hyaline; veins brown. Relative lengths of 2nd: 3rd: 4th costal sections = 6: 2.4: 1; r-m at basal 0.6 of discal medial cell. Halter pale yellow.

Abdomen yellowish brown except for tergite 1 yellow, tergites 1+2 with a pair of brown apico-lateral spots; venter yellow. Setulae brown.

Male genitalia ( Figs. 28–31 ): Epandrium brown with long brown setulae, height 1.7 times width in lateral view; surstylus slightly shorter than depth of epandrium, nearly parallel-sided in lateral view, broad distally, some thickened setae on inner side of lateral and distal portions. Cercus broad basally, distal 2/3 narrow, finger-like, directed medioventrally, with a point apex, with some long setulae. Pre- and postgonites short, postgonite round distally, bearing a minute serrulation on ventrodistal margin, with few sensilla; basiphallus longer than wide, cylindrical; distiphallus shorter than basiphallus, membranous; phallapodeme sclerotized, long, with basal stalk broad in lateral view. Hypandrium closed, apically forming an arch.

Female. Body length 2.2 mm, wing length 1.9 mm. External characteristics similar to male.

Type material. HOLOTYPE 6, CHINA, Hainan, Diaoluoshan Mountain , 28. V-11. VI. 2007, Jie Zeng Leg. (CAU) (photo and abdomen dissected). PARATYPES 1 6, 1 ♀, same data as holotype ( CAU). All type specimens were stored in 75% ethanol .

Distribution. China (Hainan).

Remarks. The new species is somewhat similar to D. longisurstylus Ismay, 1984 , but can be separated from the latter by the following features: scutum with 3 longitudinal reddish yellow stripes except for lateral stripes brownish basally; first flagellomere round dorsodistally; cercus broad basally, distal 2/3 narrow, finger-like; postgonite bearing a minute serrulation on ventrodistal margin. In D. longisurstylus , the scutum has 3 black stripes; the first flagellomere has a dorsodistal angle; the cercus is narrow and pointed; and the postgonite has not minute serrulation on ventrodistal margin ( Ismay 1984).

Etymology. The specific name is from the Latin minut- (“small”) and dentatus (“denticulate”), and refers to the ventrodistal margin of postgonite with a minute serrulation.

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 28–31. Dicraeus minutidentatus sp. nov. male. 28 epandrium, posterior view; 29 epandrium, lateral view; 30 hypandrium and phallic complex, ventral view; 31 hypandrium and phallic complex, lateral view. Scale bar = 0.1 mm.