Rhodesiella uncata, 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 : 381

Rhodesiella uncata sp. nov.

Figs 4 , 8 , 21–24

Diagnosis. Gena 0.33 times as deep as depth of first flagellomere. Antenna yellow except for dorso-distal portion of first flagellomere brownish black. Scutellum 1.3 times as long as wide, with 3 pairs of yellow scutellar setae on tubercles which are black on basal 1/2 and yellow on distal 1/2, 2 times as long as wide. Surstylus very large, 1.75 times as long as epandrium in lateral view. Pregonite well developed with stripes on surface and a hook-like distal process on inner margin.

Description. Male ( Figs. 4 , 8 ). Body length without antennae 2.90mm, wing length 2.84mm.

Head black, much wider than long, length, width and height ratio as 1: 2.2: 1.3; frons brownish black, 0.9 times as long as wide, width measured at level of anterior ocellus, projecting only slightly in front of eye; face concave, brownish black; gena narrow, brownish black, 0.33 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. Cephalic setae and setulae yellow. Antenna yellow except for dorso-distal partion of first flagellomere brownish black, first flagellomere 0.8 times as long as deep; arista slender, black except for basal segment yellow with short pubescence. Proboscis yellow with yellow setulae; palpus yellowish brown with yellow setulae.

Thorax black, as wide as head. Scutum convex, slightly broader than long. Scutellum black, elongate, subtriangular, 1.3 times as long as wide and 0.8 times as long as scutum, 3 pairs of yellow scutellar setae standing on tubercles which are black on basal 1/2 and yellow on distal 1/2, 2 times as long as wide. Ap sctl s 0.9 times as long as scutellum and 2.5 times as long as basal l sctl s; distal l sctl s about 1.5 times as long as basal l sctl s. Distance between tips of tubercles of ap sctl s longer than that between those of basal and distal l sctl s, distance between tips of tubercles of ap sctl s and distal l sctl s equal to that between those of ap sctl s. Thoracic setulae and setae yellow; npl s 1+1. Legs yellow except for hind tarsomeres 5 brown. Setulae on legs mostly yellow. Mid-tibia with a distinct, yellow brown apical spur. Hind femur not thickened, 1.6 times as broad as succeeding tibia at middle. Wing hyaline, 2.5 times as long as wide; veins brown; relative lengths of costal sections 2nd: 3rd: 4th = 2.9: 1: 1; crossvein r-m distad beyond middle of discal cell, at basal 0.57 of its length; R 4+5 and M 1+2 nearly parallel medially; ultimate section of M 1+2 slightly forecurved basally. Halter pale yellow.

Abdomen brown except for tergites 1+2 light yellow, tergite 2 brown laterally; venter yellow to brown. Setulae on abdomen brownish black to yellowish brown.

Male genitalia ( Figs. 21–24 ): Epandrium brownish black with yellowish brown setulae, wider than long in dorsal view and as long as high in lateral view. Surstylus brownish black, well developed, very large, nearly elliptic, 1.75 times as long as epandrium in lateral view. Hypandrium also well developed, concave medially, lateral margins corrugated and broadened at middle. Pregonite developed, 2 times as long as wide, with 8-9 stripes on surface and a hook-like distal process on inner margin. Postgonite incurved at middle. Pregonite significantly wider than postgonite. Distiphallus short, cylindrical in dorsal view, slightly widened medially.

Female. Body length without antennae 3.50mm, wing length 3.00mm. External characteristics similar to male, except for tarsomeres 5 yellowish brown; tergite 2 entirely yellow.

Type material. Holotype ♂, CHINA: Xizang: Linzhi, Tongmai , 30°6’N, 95°4’E, 24. viii. 2011, leg. Lihua Wang ; Paratypes 1 ♂, 1 ♀, CHINA: Xizang: Motuo, Baricun , 29°19’N, 95°21’E, 28. viii. 2018, 1772 m a.s.l., leg. Tingting Zhang.

Etymology. The specific name is from the Latin uncatus (“uncinate”), referring to the shape of apex of pregonite.

Remarks. The new species is similar to R. monticola KaNmIYa,1987 from Taiwan in the following features: ocellar triangle polished black; scutellum with 3 pairs of yellow scutellar setae on tubercles which are black on basal 1/2 and yellow on distal 1/2, 2 times as long as wide; legs mostly yellow except tarsomere 5 brown, hind femur not thickened. But it can be separated from R. monticola by the following features: distance between tips of tubercles of basal and distal l sctl s shorter than that between those of ap sctl s; pregonite well developed, very large, with 8-9 stripes on surface and a hook-like distal process on inner margin; In R. monticola , the distance between tips of the tubercles of basal and distal l sctl s is equal to that between those of ap sctl s; and the pregonite is narrow distally with a laterobasal projection ( Kanmiya, 1987).

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 21–24. Rhodesiella uncata sp. nov. male. 21 epandrium, posterior view; 22 epandrium, lateral view; 23 hypandrium and phallic complex, ventral view; 24 Scutellum, dorsal view. Scale bar = 0.1 mm.