Dicraeus dentatus, 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 : 357-359

Dicraeus dentatus sp. nov.

Figs 3 , 20–23

Diagnosis. Gena 0.5 times as wide as first flagellomere. Ocellar triangle reaching anterior 0.9 of frons. Scutum and scutellum black. Legs largely yellow except for femora and hind tibia black with both ends yellow, tarsomeres 5 blackish brown. Surstylus nearly parallel-sided, round distally. Cercus long, with a small odontoid process distally, directed medioventrally. Postgonite bearing minute serrulations on apical margin.

Description. Male ( Fig. 3 ). Body length 2.5 mm, wing length 2.4 mm.

Head black, 1.2 times as wide as thorax, 0.85 times as long as high in profile, face yellow with brown sides, somewhat concave in lateral view, facial carina indistinct; frons brown with yellow anterior 1/6, 0.9 times as long as wide, projecting slightly in front of eye; gena broad, about 0.5 times as wide as first flagellomere, with few brown setulae on ventral margin; parafacial indistinct; clypeus light brown; vibrissal angle obtuse. Ocellar triangle brown, smooth, shiny, reaching anterior 0.9 of frons, with pointed apex; ocellar tubercle black. Postgena and occiput black. Cephalic setae and setulae black. Antenna yellow with thick grey pruinescence except for dorsodistal portion of first flagellomere blackish brown; first flagellomere 0.9 times as long as wide; arista brown with short brown pubescence. Proboscis brown to yellow with brown setulae; palpus brown with black setulae.

Scutum black, 1.1 times as long as wide. Thoracic pleuron shiny brown. Scutellum black, 0.6 times as long as wide; apical scutellar seta slightly longer than scutellum; subapical scutellar seta as long as scutellum. Postscutellum black. Setae and setulae on thorax black; notopleurals 1+2, anterior notopleural seta as long as posterior notopleural seta; anterior postalar seta slightly longer posterior postalar seta; 1 pair of dorsocentral setae developed, as long as anterior postalar setae. Legs slender, coxae yellow except basal portion of mid coxa black, femora and hind tibia black with both ends yellow, fore and mid tibiae yellow, tarsi yellow with tarsomeres 5 blackish brown. Mid tibia with a short black subapical spur, which is shorter than diameter of tibia. Tibial organ long and narrow. Setulae on legs black. Wing 2.6 times as long as wide, hyaline; veins brown. Relative lengths of 2nd: 3rd: 4th costal sections = 5: 1.7: 3; r-m at basal 0.6 of discal medial cell. Halter pale yellow.

Abdomen brown except for tergite 1 and venter yellow. Setulae brown.

Male genitalia ( Figs. 20–23 ): Epandrium brown with long brown setulae, height 1.3 times width in profile; surstylus slightly shorter than depth of epandrium in profile, nearly parallel-sided, round distally. Cercus long, 0.4 times as long as surstylus, with a small odontoid process distally, directed medioventrally. Pre- and postgonites short, postgonite with few sensilla, round distally, bearing minute serrulations on apical margin; basiphallus longer than wide, cylindrical; phallapodeme sclerotized, long, basal stalk broad with narrow basally in lateral view. Hypandrium closed, apically forming an arch.

Female. Unknown.

Type material. HOLOTYPE 6, CHINA, Taiwan , Nantou , Lushan Mountain, Tunyuan, 19. VI. 2011, Xiaoyan Liu Leg. (CAU) (photo and abdomen dissected). PARATYPES 2 66, same data as holotype ( CAU). All type specimens were stored in 75% ethanol .

Distribution. China (Taiwan).

Remarks. The new species is somewhat similar to D. nitidiventris Kanmiya, 1971 , but can be separated from the latter by the following features: all femora black with both ends yellow; abdomen brown except for tergite 1 yellow; cercus long, 0.4 times as long as surstylus, with a small odontoid process distally. In D. nitidiventris , only the fore femur is black; the abdomen is entirely black; and the cercus is small and vestigial ( Kanmiya 1971).

Etymology. The specific name is from the Latin dentatus (“dentiform”), referring to the shape of cercus.

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 20–23. Dicraeus dentatus sp. nov. male. 20 epandrium, posterior view; 21 epandrium, lateral view; 22 hypandrium and phallic complex, ventral view; 23 hypandrium and phallic complex, lateral view. Scale bar = 0.1 mm.