Sybistroma genriki Grichanov, 2020

Grichanov, I. Ya., 2020, A new species of Sybistroma Meigen, 1824 (Diptera: Dolichopodidae) from China, Far Eastern Entomologist 418, pp. 1-8 : 4-7

Sybistroma genriki Grichanov , sp. n.

http://zoobank.org/NomenclaturalActs/ 0DCB4A4C-F646-420F-8CF1-666ED051344F

Figs 1 –13

TYPE MATERIAL. Holotype – ♂ (dried), China: “ CH, Yunnan, ENE ShangriLa, 2.55 km N Mizhu, Potatso NP, 27°53’35” N / 99°54’18” E, H= 3935 m, 11. VI

2019, Belousov, Davidian, Kabak leg.” [ ZIN]. Paratypes (in ethanol): 1♂, 4♀, same data as holotype; 1♂, 2♀, “ CH, Yunnan, NW Shangri-La, 2.25 km E Nixi ,

28°04’10” N / 99°31’05” E, H= 3835 m, 13.VI 2019, Belousov, Davidian, Kabak leg.”; 2♂, 4♀,“ CH, Yunnan, E Shangri-La, 3.45 km NE Hongpocun Vill. ,

27°50’52” N / 99°49’57” E, H= 3675 m, 07.VI 2019, Belousov, Davidian, Kabak leg.”. The holotype has its male terminalia dissected and stored in glycerin in a microvial pinned with the source specimen. Types are deposited in the collection of the Zoological Institute of the Russian Academy of Sciences .

DESCRIPTION. Male. Head. Antenna with first three segments mostly yellow,

with scape and postpedicel blackish dorsally; arista-like stylus mostly black, but snow-white at apex of filiform part and at basal 1/3 of apical swelling; scape with dorsal setae; pedicel reduced (from outer view), slightly protruded into postpedicel

(from inner view); postpedicel conoid, 2.9 times as long as high; stylus apical, micro-

scopically haired, with fused segments 1 and 2; apical swelling of stylus truncated at apex, 4 times as long as wide; length (mm) of scape, pedicel, postpedicel, stylus,

0.18/0.06/0.38/1.66; frons bronze-blue-black, grey pollinose; eyes finely haired;

face black, weakly whitish grey pollinose; ratio of height to width under antennae to width at clypeus, 12/4/1; palpus yellow, sparsely covered with small black setae;

proboscis yellow; upper postocular setae black; middle and lower postocular setae white.

Thorax. All bristles black; pronotum pubescent, with black hairs; mesonotum grey pollinose; 6 dorsocentral setae; acrostichals short, biserial; pleura dark, with weak grey pruinosity; scutellum with 2 strong setae, 2 fine lateral setae.

Legs mostly yellow; mid and hind coxae mostly black; hind femur brown-black at apex; fore and mid tarsi from tip of basitarsus and hind tarsus black; hairs and setae black; all tarsi simple; fore leg with coxa bearing white and brown hairs laterally and strong black setae apically, femur without subapical posterior seta, tibia with 2

short anterodorsal, 2 strong posterodorsal setae, no long apicoventral seta; mid leg with coxa bearing some brown and black hairs laterally and 1 strong seta, femur with

1 anterior subapical seta, tibia with 3 anterodorsal, 3 posterodorsal, 2 anteroventral,

1 posteroventral and 4 apical setae; hind leg with coxa bearing 1 strong seta, femur with 1 anterior subapical seta and some posterodorsal cilia, tibia with 2 anterodorsal,

4 – male wing; 5 – female habitus; 6 – female head; 7 – female antenna.

4 posterodorsal and 4–5 ventral setae. Femur, tibia and tarsomere (from first to fifth) length ratio: fore leg: 1.07/1.1/0.67/0.28/0.23/0.16/0.13, mid leg: 1.33/1.72/

0.99/0.39/0.3/0.21/0.17, hind leg: 1.77/2.14/0.75/0.61/0.42/0.24/0.23.

Wing. Membrane greyish, veins brown; R1 thickened; costa thickened, with short brown setae dorsally; R2+3 almost straight, R4+5 curved towards M1+ 2 in apical fourth, M and R4+5 slightly convergent distally, becoming parallel at apex;

M joining costa right before wing apex; ratio of costal section between R2+3 and

R4+5 to that between R4+5 and M1+2: 0.57/0.13, distal part of M4 2.2 times longer than dm-m; anal vein distinct; lower calypter yellow, with black cilia; halter yellow.

gium, ventral view; 10 – epandrial lobes and phallus, left lateral view; 11 – epandrial lobes,

right lateral view; 12 – cercus, outer view; 13 – postgonite and lobes of surstylus.

ment as long as hypopygium; 8th segment black, with black cilia. Male genitalia with epandrium black, elongate-oval, 1.7 times as long as high; hypandrium flanked laterally by long and thin basiventral epandrial lobes forming tripartite arrangement in ventral view; basiventral epandrial lobes symmetrical, each lobe spear-shaped with flat apical knob; phallus thin and long, with large sclerotized lateral projections

(parameral sheath); surstylus yellow, with 2 long and thin lobes; ventral lobe straight,

with short apical setae; dorsal lobe of surstylus deeply bifurcated, with dorsal arm half as long as ventral arm, with 1 long apical seta; postgonite thin, as long as surstylus, trilobed at apex; cercus dark brown; 2 times longer than wide, with 2

wide distal emarginations, with light and dark simple setae, short basally and long distally (Fig. 12).

MEASUREMENTS. Body length 4.5 mm, antenna length 2.2 mm, wing length

4 mm, wing width 1.4 mm, hypopygium length 0.8 mm.

FEMALE. Similar to male except lacking male secondary sexual characters,

otherwise as follows. Body length 3.9 mm, antenna length 0.9 mm, wing length 4.3

mm. Face black, weakly grey pollinose, nearly parallel-sided; ratio of its height to width at clypeus, 0.45/0.25; antenna mostly blackish brown, yellow ventrally; postpedicel ovate, nearly 1.5 times as long as high; stylus dorsoapical, bisegmented;

length (mm) of scape, pedicel, postpedicel, stylus (segments 1 and 2), 0.2/0.14/

0.26/0.12/0.67.

DIAGNOSIS. Antenna mostly yellow, with stylus much longer than postpedicel; postpedicel elongated, 2.9 times as long as high, acute apically; aristalike stylus apical, with dark and white apical swelling; lower postocular setae white;

legs mostly yellow except mostly black mid and hind coxae and brown-black distal spot on hind femur; all tarsi simple, mostly dark. This species belongs to S. incisa group of species and keys to S. apicicrassa (Yang et Saigusa, 2001) known from

Henan and Shaanxi provinces of China (Yang et al., 2011). Its cercus superficially resembles the cercus of S. incisa , but the latter species differs from the new species in the short antennal postpedicel, preapical arista-like stylus, two dark swellings on stylus, entirely yellow hind femur, fine morphological characters of hypopygium

(Yang et al., 2011: fig. 692). S. apicicrassa differs from the new species in the simple cercus, dark swelling on stylus, entirely yellow hind femur, fine morphological characters of hypopygial appendages (Yang et al., 2011: fig. 678).

ETYMOLOGY. The species is named for the Russian entomologist, Dr. Genrik

Davidyan, one of the collectors of the type series.

Figures

Figs 1–7. Sybistroma genriki sp. n. 1 – male habitus; 2 – male head; 3 – male antenna;