Wiedemannia ivkovicae, 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 : 357-358

Wiedemannia ivkovicae sp. nov.

( Fig. 6 )

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.] / 25.vii.2013, D. Zherebilo ( ZIN)”. PARATYPES: SOUTH OSSETIA: same data as holotype (4 ♂, KSU); Gudiysskiy ridge, source of River Britadon, northern slope of the Mountain Mangavtsek, 2700 m a.s.l., 21.vii.2013, D. Zherebilo (2 ♂, 10 ♀, ZIN; 2 ♂, 10 ♀, KSU); Gudiysskiy ridge, source of River Britadon, northern slope of the Mountain Mangavtsek, 2900 m a.s.l., 24.vii.2013, D. Zherebilo (4 ♀, KSU); Central Caucasus, South Ossetia, the north-eastern slope of Mount Britavtsak, left bank of River Britadon, 2500 m a.s.l., 42°29'13.4"N, 044°10'34.6" E, 21.vii.2013, D. Zherebilo (1 ♀, KSU).

Diagnosis. This species is distinguished by its large size, the distinct and elongate pterostigma, acrostichals divergent around prescutellar depression, 5 pairs of dorsocentrals, dark brown scutum with greenish-blue pruinescence on prescutellar depression, postpronotal lobe and lower margin of notopleuron; 2–3 anterior setae on fore femur and elongate unilobed male clasping cercus with its finger-like apical prolongation.

Description. Male. Body length 4.0– 5.5 mm; wing length 6.0– 6.8 mm. Head dark brown, occiput and gena with faint greenish-blue pruinescence, face, frons and vertex with brownish pruinescence. Gena broad, about 1/4 height of eye. Face wide, distinct carina on lower margin. Pair of rather strong ocellar setae (subequal postpronotal setae) and one pair of vertical setae, about 3–5 distinct upper postoculars; all similarly sized and black, with interspersed shorter setae. Lower postocular setae much finer and paler merging with pale, longer setae on middle and lower occiput. 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/ 2X longer than scape, with complete circlet of apical setae; postpedicel longer, apically pointed, stylus twice as long as postpedicel, tip blunt. Palpus with numerous dark dorsal setae. Thoracic pleura with blue pruinescence; scutum dark brown; prescutellar depression with greenish-blue pruinescence, extending onto concolorous scutellum; postpronotal lobe and lower margin of notopleuron with greenish-blue pruinescence. Antepronotum with pair of dark setae and some fine setulae. Proepisternum with whitish fine setulae. Acrostichals small and fine, irregularly biserial, divergent around prescutellar depression; 5 pairs of dorsocentrals with interspersed numerous shorter setae. 1 postpronotal seta, 2 notopleural setae (upper stronger), 1 presutural supra-alar seta and numerous scattered setulae; 1 postalar seta; 1 pair strong scutellar setae (usually with 2 weak setae). Laterotergite with patch of fine, pale setulae. Legs entirely dark brown, 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. Wing membrane infuscate, veins darker; pterostigma distinct, elongate, brown, single basal costal seta extending to humeral crossvein. 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, slightly greenish on sternites. Terminalia ( Fig. 6 ): hypandrium subequal in length to epandrium, bearing several setae. Epandrium rounded apically, covered with numerous dark long setae especially ventrally and laterally; small spine-like surstylus emerging from inner face apically. Clasping cercus unilobed, basal half strongly expanded medially clothed with fine setulae; apical half prolonged and fingerlike, arched medially and club-shaped apically; posterior margin of lower half with row of long setae. Phallus more or less linear, brownish; distiphallus without swelling in middle. Female. Similar to male, except terminalia; cercus short ovate and minutely pilose.

Distribution. PALAEARCTIC: South Ossetia.

Remarks. Wiedemannia ivkovicae sp. nov. is most similar to W. horvati Ivković & Sinclair, 2014 , described from high altitude biotopes of Spain ( Ivković et al. 2014) and W. thienemanni Wagner, 1982 ( Wagner, 1982) , described from Austria ( Wagner 1982). The new species differs by longer wings (in W. horvati length 5.4−5.6 mm, in W. thienemanni length 5 mm), 2–3 anterior setae on fore femur (4–5 in W. horvati ) and structure of terminalia: clasping cercus in new species more expanded on basal half and club-shaped apically (longer and not club-shaped apically in similar species); in new species the lengths of epandrium and clasping cercus are subequal (in W. thienemanni epandrium is distinctly shorter than clasping cercus).

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

Etymology. The new species is named after the Croatian entomologist, Dr Marija Ivković (Zagreb, Croatia), who has made valuable contributions to the knowledge of aquatic Empididae in Europe.

Figures

FIGURES 1 – 6. Male terminalia of Wiedemannia, lateral view. 1, W. beckeri (Mik); 2, W. braueri (Mik); 3, W. caucasica Joost; 4, W. chvali Joost; 5, W. fallaciosa (Loew); 6, W. ivkovicae sp. nov. Scale bar = 0.1 mm. Abbreviations: cerc pl—cercal plate; cl cerc—clasping cercus, distph—distiphallus, epand—epandrium, hypd—hypandrium, ph—phallus.