Empis (Polyblepharis) altaica, Shamshev, 2019

Shamshev, I. V., 2019, Six new species of the genus Empis (Diptera: Empididae) from the Altai Mountains of Russia, Zoosystematica Rossica (Zoosyst. Rossica) 28 (1), pp. 24-41 : 25-27

Empis (Polyblepharis) altaica sp.nov.

( Figs 1–3 )

Holotype. Male , “ RUSSIA, Altai Rep. [= Republic of Altai], / Shebalino distr., 5 km SE [of] vill. / Topuchaya, 1325 m, / 51°06'N 85°37'E, 3– 4.07.2014, leg. I. Shamshev ”, “ Empis (Polyblepharis) altaica Shamshev , sp. n. [red label]” ( ZIN, INS _DIP_0000604).

Paratypes. Russia: 1 female, same data as for holotype ; 1 male, Altai Terr., Krasnoshchekovskiy Distr. , environs of Tigirek Vill., 25.VI.2005, D. Kostrov leg. (both in ZIN, male dissected) .

Diagnosis. Small black species with dichoptic eyes in both sexes, black palpus, scutum with four shiny vittae, entirely black legs, minute acrostichals and dorsocentrals, laterotergite with pale setae, abdomen with tergites extensively shiny, covered only with pale hair-like setae; male hind femur incrassate.

Description. Male ( Fig. 1 ). Body length 4.1 mm (holotype and paratype); wing length 4.5 mm (holotype and paratype).

Head black. Eyes dichoptic, ommatidia of equal size. Frons broad, nearly as wide as distance between inner margins of posterior ocelli, mostly parallel-sided, somewhat widened just above antennae, densely dark brown pruinose, with marginal setulae. Face wide, parallel-sided, largely greyish brown pruinose, narrowly shiny along lower margin, bare; clypeus shiny. Occiput faintly greyish pruinose, with numerous moderately long black setae irregularly spread over upper part and some hair-like yellowish setae on lower part behind mouth-opening and closer to neck. Ocellar tubercle concolourous with occiput, with several setulae. Antenna black; scape rather short, about 1.5 times as long as pedicel, both with short setulae; postpedicel moderately long, nearly 2.5 times as long as wide, with ventral margin slightly concave on subapical part; stylus about half as long as postpedicel. Proboscis moderately long; labrum brownish to brownish yellow, nearly 1.5 times as long as head height; palpus short, black, with very sparse minute dark and yellowish setulae.

Thorax black, densely brownish grey pruinose (except as noted); scutum with four distinct shiny vittae (in dorsal view); setation mostly black. Prosternum bare. Proepisternum with numerous long hair-like pale setae on lower part, bare on upper part. Antepronotum with numerous setae of different length and robustness dorsally and 2–3 pale hair-like setae laterally. Postpronotal lobe with one long and several short setae, also with some pale setulae anteriorly. Mesonotal setation well-differentiated: one moderately long presutural intra-alar, one long presutural supra-alar, three notopleurals (with some black and pale setulae anteriorly), one postsutural supra-alar (with additional setula anteriorly), one long and one minute postalars, two long and two very short scutellars; acrostichals arranged in two close irregular rows, very short, thin, numerous, lacking on prescutellar depression; dorsocentrals uniserial, nearly as long as acrostichals, except two pairs of long prescutellars. Laterotergite with numerous pale hair-like setae. Anterior and posterior spiracles black.

Legs rather robust, entirely black, with black setation (except as noted); coxae faintly greyish pruinose, other parts of legs subshiny. Coxae and trochanters with simple pale and black setae; fore coxa covered with pale hair-like setae anteriorly. Fore femur bare ventrally, covered with short setulae somewhat longer on subapical part anteriorly and posteriorly. Fore tibia with three short thin dorsal setae (besides circlet of very short subapicals). Mid femur with whitish pubescence ventrally, bearing short strong anteroventral and short strong posteroventral setae in about apical two-thirds. Mid tibia with a short anterodorsal seta near middle. Hind femur thickened, about 1.5 times as broad as mid femur, with whitish pubescence ventrally, covered with dense spinules ventrally, bearing complete rows of long strong anteroventral and long strong posteroventral setae. Hind tibia slender, without strong setae, with erect setulae ventrally and with one short seta in posteroapical comb. Tarsi of all legs similar in structure and vestiture; tarsomeres covered with short setulae (except circlet of very short subapical setae on tarsomeres 1–4); basitarsus slender, with very short anteroventral and posteroventral spinule-like setae; claws long.

Wing membrane very faintly brownish infuscate. Pterostigma brownish yellow, narrow. Basal costal seta absent. Veins R 5 and M 1 somewhat divergent in subapical parts; radial fork acute. Cell dm short. Anal angle acute, subsequently anal lobe well developed. Calypter yellowish, pale fringed. Halter yellow.

Abdomen entirely black. Tergite 1 entirely and tergite 2 anteriorly faintly greyish pruinose, both subshiny, tergites 6 and 7 with large brownish iridescent spots dorsally, otherwise tergites shiny; tergites covered with pale hair-like setae being shorter dorsally and longer laterally, posteromarginal setae lacking. Sternites subshiny, faintly greyish pruinose, mostly with short hair-like pale to brownish yellow setae, sternites 6 and 7 with longer black posteromarginal setae. Tergite 6 unmodified; tergite 7 mostly hidden, with broadly concave posterior margin; sternite 7 with slightly produced posterior angles. Sclerites of segment 8 separated; tergite 8 represented by two broadly separated subtriangular sclerites; sternite 8 partly hidden by sternite 7, scoop-shaped, constricted near base, anteriorly with two small lateral tubercles on lower part and one tubercle on upper part. Terminalia ( Fig. 2 ) moderately large, almost entirely black, only phallus yellowish. Cercus elongate oval (in lateral view), with smoothed inner margin and lateral lobe (in dorsal view), covered with minute yellowish and dark setulae. Epandrial lamella rather rhomb-like (in lateral view), covered with scattered pale and dark setulae being somewhat longer along the lower margin. Hypandrium rather truncate apically (in ventral view), bare. Phallus ( Fig. 3 ) divided; distiphallus with apical portion slender, evenly curved backwards.

Female. Body length 4.6 mm; wing length 4.5 mm. Similar to male except sexually dimorphic and the following characters. Mid femur bare ventrally, with minute anteroventral and posteroventral spinule-like setulae. Mid tibia with two anterodorsal setae. Hind femur slenderer, bare ventrally, with five short strong anteroventral setae in about apical half. Hind tibia thicker, with simple setulae ventrally. Abdominal tergites subshiny, faintly greyish pruinose; setation shorter. Cercus long, slender, covered with dark setulae.

Comparison. The new species is similar to E. eversmanni Loew, 1873 distributed in steppe regions of eastern and, locally, Central Europe. The typical form of E. eversmanni differs from E. altaica sp. nov. in the mesonotum partly reddish yellow. The specimens with entirely black mesonotum can be readily distinguished from the new species primarily by blackish halteres.

Etymology. The epithet refers to the region where the new species was collected.

Distribution. Palaearctic: Russia (Republic of Altai, Altai Terr.).

Habitat and seasonal occurrence. The holotype male and a female were collected on a montane meadow in June–July.

Figures

Figs 1–3. Empis (Polyblepharis) altaica sp. nov., male. 1, habitus, lateral view (holotype); 2, terminalia, lateral view; 3, phallus, lateral view. Abbreviations: cerc, cercus; ej apod, ejaculatory apodeme; epand, epandrium; hypd, hypandrium; ph, phallus. Scale bar: 0.1 mm.