Rhodesiella perpendicularis, Cai & Yang & Nartshuk & Liu, 2021

Cai, Xiaodong, Yang, Ding, Nartshuk, Emilia P. & Liu, Xiaoyan, 2021, Four new species of the genus Rhodesiella from Xizang Autonomous Region, China (Diptera: Chloropidae), Zootaxa 4970 (2), pp. 372-384 : 379

Rhodesiella perpendicularis sp. nov.

Figs 3 , 7 , 17–20

Diagnosis. Gena 0.1 times as deep as depth of first flagellomere. Antenna entirely yellow. Scutellum 1.5 times as long as wide, bearing 3 pairs of yellow scutellar setae on tubercles which are black on basal 1/2 and yellow on distal 1/2, 3 times as long as wide. Surstylus slightly longer than wide, nearly peach-shaped in lateral view. Postgonite relatively small and highly incurved at middle.

Description. Male ( Figs. 3 , 7 ). Body length without antennae 2.40–2.60mm, wing length 2.10–2.20mm.

Head black, length, width and height ratio as 1: 1.8: 1.2; frons brownish black, 0.56 times as long as wide, width measured at level of anterior ocellus, projecting only slightly in front of eye; face concave, brown; gena yellowish brown, narrow, 0.1 times as deep as depth of first flagellomere; parafacial inconspicuous. Ocellar triangle polished black, smooth, reaching the anterior margin of frons with obtuse apex; ocellar tubercle yellowish brown. Occiput polished black. Clypeus brownish black. Setulae and setae on head yellow. Antenna yellow, first flagellomere 0.7 times as long as deep; arista slender, brown with short pubescence. Proboscis yellow with yellow setulae; palpus yellowish brown with brown setulae.

Thorax black, slightly narrower than head. Scutum convex, as long as wide. Scutellum black, elongate, subtriangular, 1.5 times as long as wide and 0.8 times as long as scutum, baring 3 pairs of yellow scutellar setae on tubercles which are black on basal 1/2 and yellow on distal 1/2, 3 times as long as wide. Ap sctl s 0.72 times as long as scutellum and 2.3 times as long as basal l sctl s; distal l sctl s 1.24 times as long as basal l sctl s. Distance between tips of tubercles of ap sctl s and distal l sctl s longer than that between those of ap sctl s; distance between tips of tubercles of ap sctl s longer than that between those of basal and distal l sctl s. Setulae and setae on thorax yellow; npl s 1+1. Legs light yellow except for hind tibia brown with both tips yellow, tarsomeres 5 brown. Setulae on legs mostly light yellow. Mid-tibia with a distinct, yellow apical spur. Hind femur not thickened, 1.4 times as broad as succeeding tibia at middle. Wing hyaline, 2.3 times as long as wide; veins brown; relative lengths of costal sections: 2nd: 3rd: 4th = 2.5: 1.5: 1; crossvein r-m proximad of middle of discal cell, at basal 0.46 of its length; R 4+5 and M 1+2 nearly parallel medially; M 1+2 slightly concave forward basally. Halter pale yellow.

Abdomen brown except for tergites 1+2 pale yellow; venter pale yellow. Setulae on abdomen mostly brownish black.

Male genitalia ( Figs. 17–20 ): Epandrium yellowish brown with yellow setulae, wider than long in dorsal view. Surstylus yellowish brown with yellow setulae, longer than epandrium in dorsal view, slightly longer than wide, nearly peach-shaped in lateral view. Hypandrium laterally broadened. Pregonite distinctly wider than postgonite, with a finger-like process; postgonite relatively small and highly incurved at middle, near right angle. Distiphallus elongate, cylindrical, distal 1/4 widened in dorsal view.

Female. Body length without antennae 3.00mm, wing length 2.40mm. External characteristics similar to male, except for tergite 2 light brown.

Type material. Holotype ♂, CHINA: Xizang: Motuo, Miricun , 29°25’N, 95°24’E, 28. viii. 2019, 840 m a.s.l., leg. Qicheng Yang ; Paratypes 5 ♂♂, 1 ♀, same data as holotype ; 1 ♂, Xizang: Motuo, Beibeng , 28°37’N, 94°31’E, 31. viii. 2012, 700 m a.s.l., leg. Wenliang Li ; 1 ♂, Xizang: Motuo , 29°19’N, 95°20’E, 26. viii. 2012, 1100 m a.s.l., leg. Xuankun Li ; 1 ♂, Xizang: Motuo , 29°19’N, 95°20’E, 28. viii. 2012, 1100 m a.s.l., leg. Wenliang Li.

Etymology. The specific name is the genitive of the Latin perpendiculus (“perpendicular”), referring to the shape of postgonite.

Remarks. The new species is similar to R. postinigra YaNG & YaNG, 1993 from Yunnan in the following features: 3 pairs of yellow scutellar setae standing on tubercles which are black on basal 1/2 and yellow on distal 1/2; distance between tips of tubercles of ap sctl s and distal l sctl s longer than that between those of 2 ap sctl s, distance between tips of tubercles of 2 ap sctl s longer than that between those of basal and distal l sctl s; and hind femur not thickened. But it can be separated from R. postinigra by the following features: proboscis yellow; surstylus longer than epandrium in dorsal view; hypandrium broad laterally. In R. postinigra , the proboscis is light black; the surstylus is 1.5 times as long as epandrium in dorsal view; and the hypandrium is narrow laterally, slightly widened at middle ( Yang & Yang, 1993).

Figures

FIGURES 1–4. Rhodesiella species, male habitus, lateral view. 1 R. arcuata sp. nov.; 2 R. longiseta sp. nov.; 3 R. perpendicularis sp. nov.; 4 R. uncata sp. nov. Scale bar = 0.5 mm.

FIGURES 5–8. Rhodesiella species, male habitus, dorsal view. 5 R. arcuata sp. nov.; 6 R. longiseta sp. nov.; 7 R. perpendicularis sp. nov.; 8 R. uncata sp. nov. Scale bar = 0.5 mm.

FIGURES 17–20. Rhodesiella perpendicularis sp. nov. male. 17 epandrium, posterior view; 18 epandrium, lateral view; 19 hypandrium and phallic complex, ventral view; 20 Scutellum, dorsal view. Scale bar = 0.1 mm.