Wiedemannia nartshukae, Kustov, Semen & Zherebilo, Danil, 2015

Kustov, Semen & Zherebilo, Danil, 2015, New data on the genus Wiedemannia Zetterstedt (Diptera: Empididae) from the Caucasus with description of four new species, Zootaxa 4032 (4), pp. 351-369 : 360-361

Wiedemannia nartshukae sp. nov.

( Fig. 10 )

Type material. HOLOTYPE, ♂ labelled [printed in Cyrillic], [ SOUTH OSSETIA]: “Ju. Ossetia, Gudiysskiy hrebet [ridge] / zapadnie skloni g. [western slopes of mount] Mangavtsek/ rutchei [stream] / [3000 m a.s.l.] / 24.vii.2013, D. Zherebilo” ( ZIN). PARATYPES: SOUTH OSSETIA: same data as holotype, 24.vii.2013, D. Zherebilo (1 ♂, 1f, KSU); Central Caucasus, Gudiysskiy ridge, source of River Britadon, northern slope of the Mountain Mangavtsek, 2700 m a.s.l., 21.vii.2013, (1 ♀, KSU).

Diagnosis. This species is distinguished by acrostichals divergent around prescutellar depression, 5 pairs of dorsocentrals without intermediate setae, dark brown scutum with light blue pruinescence on prescutellar depression, postpronotal lobe and lower margin of notopleuron; proepisternum with brownish setae, laterotergite with dark setulae; 2–3 stout anterior setae on apical third of fore femur and male clasping cercus unilobed, elongated, evenly narrowed apically, posteriorly with distinct convexity basally.

Description. Male. Body length 4.1–4.6 mm; wing length 5.8–6.1 mm. Head brown, face, occiput and gena with blue pruinescence, frons and vertex with olive-brown pruinescence. Gena broad, about 1/4 height of eye. Face wide, distinct carina on lower margin. Pair of strong ocellar setae (equal postpronotal setae) and pair of vertical setae, several strong occipitals similarly sized and black, with interspersed shorter postoculars. Lower postocular and occipital setae finer and brownish. Few dark setulae present on vertex and between ocellar area and eye margin. Antenna dark brown to black, postpedicel and stylus minutely pubescent; scape with setulae dorsally, pedicel 1.5X shorter than scape, with complete circlet of apical setae; postpedicel triangular, apically pointed, stylus about twice as long as postpedicel, tip blunt. Palpus with numerous dark dorsal setae. Thoracic pleura with blue pruinescence; scutum olive-brown; prescutellar depression with light blue pruinescence, extending onto concolourous scutellum; postpronotal lobe and lower margin of notopleuron with light blue pruinescence. Antepronotum with pair of dark setae and some fine setulae. Proepisternum with brownish fine setae, longer on lower part. Acrostichals small, biserial, divergent around prescutellar depression; 5 pairs of long dorsocentrals (without intermediate setae); 1 postpronotal seta (with 2–3 shorter setae), 2 notopleurals (upper stronger), 1 presutural supra-alar seta and several scattered setulae;1 postalar seta; 1 strong pair of scutellars setae (without weak setae). Laterotergite with, fine dark (some specimens with mixed pale and brownish) setulae. Legs entirely dark brown to black, coxae with blue pruinescence. All legs with evenly distributed setae; hind tibia with longer dorsal and ventral setae on apical third. Fore femur narrowed apically, with 2–3 stout anterior setae on apical third. All coxae with longer setae anteriorly: hind coxae with pale setae, mid and fore coxae with mixed pale and blackish setae. Wing membrane infuscate, veins brown; pterostigma distinctly brown, elongate and very narrow, single basal costal seta. Origin of veins M1 and M2 widely separated at end of cell dm. R4 and R5 straight and divergent. Halter dark brown with blue pruinescence. Abdominal sclerites with blue pruinescence. Terminalia ( Fig. 10 ): Hypandrium subequal in length to epandrium, with few setae on apical part. Epandrium rhomboid, covered with numerous dark, long setae. Clasping cercus unilobed, elongated, evenly narrowed apically, posteriorly with distinct convexity basally, clothed with setulae of different length. Inner surface of posterior margin basally with numerous long setae. Phallus slightly evenly arched, brownish. Female. Similar to male, except terminalia; cercus short ovate and minutely pilose.

Distribution. PALAEARCTIC: South Ossetia.

Remarks. The new species is distinguished from related species by features outlined in the key. Wiedemannia nartshukae sp. nov. is most similar to W. (Chamaedipsia) longicornis ( Mik, 1887) , but differs from the latter by 5 pair of dorsocentrals and structure of male clasping cercus. Among species described in this article, W. nartshukae sp. nov. closely resembles W. ossetiana sp. nov., but can be distinguished by such features as brownish setae on proepisternum, dark or mixed setulae on laterotergite, light blue pruinescence on prescutellar depression, dorsocentrals without any short setae between them, and structure of the male terminalia, especially by the form of the clasping cercus.

The new species is known only from high-altitude streams and rivers of Central Caucasus (2500–3000 m a.s.l.) and is active in July.

Etymology. The new species is named in honor of Russian dipterologist, Emilia P. Nartshuk (St. Petersburg).

Figures

FIGURES 7 – 11. Male terminalia of Wiedemannia, lateral view. 7, W. klausnitzeri Joost (from Joost 1981); 8, W. kustovi Sinclair & Shamshev (from Sinclair & Shamshev 2014); 9, W. lota Walker; 10, W. nartshukae sp. nov.; 11, W. ossetiana sp. nov. Scale bar = 0.1 mm. Abbreviations: sur—surstylus.