Sympycnus ferganicus, Negrobov & Grichanov & Selivanova, 2017

Negrobov, Oleg P., Grichanov, Igor Ya. & Selivanova, Olga V., 2017, Review of East Palaearctic species of Sympycnus Loew, 1857, with a key to species, Zootaxa 4277 (4), pp. 531-548 : 534-536

Sympycnus ferganicus sp. nov.

( Figs 7–12 )

Diagnosis (male). Slender species ( Fig. 7 ). Face narrow, at clypeus obliterated. Antenna black, with postpedicel triangular with angular apex, shorter than high, and about as long as pedicel. Stylus mid-dorsal. Fore coxa pale yellow with extreme base brown. All femora pale yellow. Fore and mid femora with one rather thin preapical posteroventral bristle. Fore tibia with anterodorsal row of black bristles on apical 1/2. Fore basitarsus with ventral row of short setae. Fore tarsus with asymmetrical claws. Mid tibia with 1 small ventral bristle. Hind tarsus with tarsomeres 3–4 distinctly flattened; tarsomere 3 practically as long as tarsomere 4, with row of 3–4 posterodorsal bristles on apical 1/2; with several weaker erect posterodorsal and posteroventral bristles on tarsomeres 3 and 4 (MSSC).

Description. Male. Body length: 2.9 mm; wing length: 2.6 mm, wing width: 0.8 mm. Head ( Fig. 8 ): Frons blue-black, dusted greyish. Occiput black, dusted grey, rather convex. Face white, with shallow central furrow under antennae; narrowing below antennae, and obliterated at clypeus, bare. Palpus rather small, mostly concealed, yellow, with pale pubescence and without apical bristles. Proboscis short, black. Eyes red, pubescent. Antenna black, with scape bare dorsally and pedicel with apical circlet of bristles, rather long dorsally; postpedicel triangular with rounded apex, higher than long (6:5), and nearly as long as pedicel, with distinct pubescence, especially on apical 1/2; arista-like stylus middorsal, with short pubescence. Length ratio of scape to pedicel to postpedicel to stylus (1st and 2nd segments) in mm, 0.05/0.05/0.05/0.05/0.54. Uppermost postocular bristles strong and black; lower bristles rather thin, yellowish white, uniserial; a few longer yellowish white bristles posterior to postocular bristles on lower occiput. One pair of black postocellar bristles. Thorax: Mesonotum including pleura, postpronotum, scutellum and metapleura dark metallic blue-green, with pleura slightly dusted greyish. Thoracic bristles black; 6 pairs of rather equal-sized dorsocentrals; acrostichals biserial, strong, nearly reaching 5th dorsocentral; upper proepisternum with group of 3–4 small, white setae in front of anterior spiracle, lower proepisternum with 3 white, equal-sized (prothoracic) setae. Scutellum with 2 very strong median bristles, 2 minute laterals, and 2 pairs of fine median hairs. Legs: Overall largely pale yellow, with mid and hind coxae mainly dark brown, tarsomere 5 of fore and mid tarsi brown, hind tarsus from tip of basitarsus brown; with black major bristles. Fore coxa pale yellow with very dense pubescence of long white bristles and equal-sized white apical bristles. Mid coxa with pubescence of inclined white setae on anterior face, and one strong white bristle and a few setae on outer margin of anterior face. Hind coxa with one straight, white external bristle, as long as coxa. Trochanters yellow. Fore femur with 1 preapical posteroventral bristle, rather thin, about as long as width of femur. Mid femur with 1 strong anterodorsal and 1 very small anteroventral preapical bristle, and 1 posteroventral preapical bristle, rather thin, about as long as femur is deep. Hind femur with 1 strong anterodorsal, 1 small anteroventral and 1 small posteroventral preapical bristle. Fore tibia with anterodorsal row of 6–7 robust black bristles on apical 1/2, about as long as width of tibia; with ventral row of hairs, shorter than width of tibia. Mid tibia with 3 strong, inclined anterodorsal bristles, inserted at about basal 1/5, 1/3 and 2/3; with 2 slightly weaker posterodorsal bristles, inserted at basal 1/5 and 3/5; with 4 strong apical bristles; with 1 short ventral bristle at about basal 1/3. Hind tibia with 2 strong anterodorsal bristles; 3–5 distinctly stronger and many smaller dorsal bristles; 5 apical bristles; indistinct posterodorsal pubescence along entire length. Fore basitarsus with ventral row of short setae; segments 2–5 normal; claws asymmetrical, with posterior claw much stronger; pulvilli white, half as long as segment 5. Mid tarsomeres with short apical setae. Hind tarsus ( Fig. 10 ) with tarsomeres 3–4 nearly entirely laterally flattened; tarsomeres 1–2 with one black posterior bristle at apex, with rows of short ventral setae; tarsomere 3 practically as long as tarsomere 4, with erect and semi-erect ventral bristles on about distal half: 3–4 stronger posterodorsal bristles, inclined and slightly curved, 2–3 posteroventral erect bristles; tarsomere 4 with few weaker erect bristles at base and at apex. Femur, tibia and tarsomere (from first to fifth) length ratio in mm: fore leg: 0.7/0.73/0.31/0.11/ 0.08/0.07/0.1, mid leg: 0.88/1.05/0.54/0.24/0.18/0.13/0.14, hind leg: 1.1/1.34/0.35/0.3/0.15/0.16/0.13. Wing ( Fig. 9 ): Hyaline, slightly smoky along costa, without anal lobe; anal vein only weakly indicated. R4+5 convex anteriorly, M1+2 with smooth bend, both nearly parallel near wing apex. Proximal section of M1+2 (from crossvein r-m to crossvein dm-cu) nearly half as long as apical section. Proximal section of vein CuA1 1.2 times as long as apical section of CuA1. Apical section of CuA1 3.5 times longer than dm-cu. Halter yellow, lower calypter yellow with white fringe. Abdomen: Six abdominal segments pubescent, with segment 6 as long as segment 5. Tergites and sternites entirely dark metallic blue-green, with short black inclined setae on disc of tergites, with white inclined setae on sides; tergite 1 with strong bristles on posterior margin (brown-black on disc, and pale on sides); tergites 1 and 2 with erect white setae laterally. Sternites with white pubescence. Hypopygium ( Figs 11–12 )with epandrium black, with slight bronze reflection; hypandrium broad, dark brown, without serration; phallus narrow, with subapical lateral hook and apical process; apicoventral epandrial lobe broad, rounded at apex, with few short apical setae; surstylus distinct, short, stick-like, with few apicodorsal setae; cercus subtriangular, narrow apically, blackish, covered with white hairs and setae; postgonites broad, mostly concealed, with bifurcate ventral structure arising at base, and forming two appendages, running alongside the phallus, rounded at apex; each appendage broad to apex, slightly curved, serrate dorsally, bearing irregular rows of spikes. Female. Unknown.

Type material examined. HOLOTYPE ♂, labelled: [ Uzbekistan:] “ Shakhimardan / 5” [Shohimardon exclave within Kyrgyzstan, 39.98°N, 71.80°E] ( ZIN).

Identification. Male hind tarsus in Sympycnus ferganicus sp. nov. is close to that of S. aeneicoxa (Meigen) . Males of the new species are most easily separated from those of the latter species by the entirely pale yellow hind femur (partly black in S. aeneicoxa ) and tibia with anterodorsal row of setae (absent in S. aeneicoxa ). The asymmetrical claws on fore tarsus and white external bristle on the hind coxa are also characteristic of S. ferganicus (the claws are symmetrical and the hind coxa bears black bristle in S. aeneicoxa ). The chaetotaxy of the hind tarsus in the new species differs conspicuously from that of other related species. The inner hypopygial structures are rather specific for S. ferganicus .

Etymology. The name “ ferganicus ” refers to the Fergana Valley.

Remarks. The holotype of S. ferganicus from Shohimardon along with paratypes of S. stackelbergi sp. nov. from Oburdon , Fan Darya River , Yaghnob River and Iskander Darya River , and males of S. pulicarius (Fallén) (see below) were obtained from the unidentified material collected by a famous Russian naturalist, A.P. Fedtshenko during his Turkistan expeditions (1868–1871). This part of Fedtshenko’s large collection was probably borrowed or taken in exchange by A.A. Stackelberg ( ZIN) from ZMUM before WWII and was recently found in the ZIN collection. Many females from the same collection accompanying those males are not associated with named males because of uncertain location of the collection sites and because of poorly studied female diagnostic characters and their variability in Sympycnus species. A single female from the Shohimardon locality is strongly damaged.

Distribution. Palaearctic: Uzbekistan.

Figures

FIGURES 7 – 12. Sympycnus ferganicus sp. nov., male holotype. 7, habitus; 8, head, dorsolateral view; 9, wing; 10, hind tarsus, dorsolateral view; 11, hypopygium, left lateral view; 12, hypopygium, ventral view. Abbreviations: apv lobe = apicoventral epandrial lobe, cer = cercus, ep = epandrium, hyp = hypandrium, ph = phallus, pgt = postgonite, sur = surstylus.