Nemotelus nartshukae, Rozkošný & Vaňhara, 2018

Rozkošný, Rudolf & Vaňhara, Jaromír, 2018, A new species and two new synonyms of Mongolian Nemotelus (Diptera: Stratiomyidae), Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 58 (2), pp. 545-548 : 545-546

Nemotelus nartshukae sp. nov.

( Figs 1–9 , 17–20 )

Type material. HOLOTYPE: J, Mongolia: Dalbay, 51°01′40.5″N, 100°45′60.0″E, 1670 m, 22.vii.2007, D. Song (ID 263), in ANSP. PARA- TYPES: 1 J 1 ♀, Mongolia: Hovd Aimag, Tsookhar Nuur (salt lake), 10 km S Bulgan, N 46.03004°, E 091.62901°, elev. 1155 m, 12.vii.2009, J, Gelhaus 1234, Mongolia aquatic Insects Survey. MAIS 2009071201, both in ANSP.

Diagnosis. Related to N. pantherinus (Linnaeus, 1758) but the male head without pale spot on the frons, different abdominal pattern in both sexes, and distinct male terminalia with two long, asymmetrical ventral spines on the aedeagal complex.

Description. Male. Head almost globular in profile, subtriangular rostrum about as long as eye length ( Figs 1 , 19 ). Eyes bare, distinctly touching before middle of frons in dorsal view. Upper facets larger and conspicuously separated from smaller lower facets in line, unusually, with middle longitudinal line of rostrum in profile. Head entirely black, without pale frontal spots. Antenna black, with spindle shaped and relatively slender flagellum. Last flagellomere relatively short, barely as long as two preceding flagellomeres combined ( Fig. 4 ). Head pile white, predominantly short and fine, covering upper frons, rostrum and gena, also distinct in front of ocellar triangle, longest on lower gena.

Thorax black, only postpronotal lobe with small yellow spot, very narrow upper anepisternal margin brownish yellow and posterior margin of anepisternum narrowly shining yellow. Scutum, scutellum and postalar callus completely black. Wing hyaline including veins, vein R 4 present. Calypter white with whitish hairs, halter with darkened stem and whitish knob. Legs yellow with dark pattern: coxae black, trochanters brownish, femora yellow with blackish medial third, tibiae brownish yellow, fore and hind tibia each with narrow brown medial ring. Ring on hind tibia usually broader and almost black. All tar- someres whitish. Thoracic pile mostly whitish, hairs on prescutellar area reaching length of two basal antennal segments combined.

Abdomen shining black dorsally, with bright yellow margin beginning at posterior corners of tergite 2 and merging with yellow lateral spots on tergites 3 and 4 ( Fig. 5 ). Small yellow, rounded or subtriangular medial spots present on tergites 2–4. Tergite 5 with broad yellow margin. Yellow margin on venter beginning at posterior corners of sternite 1 and gradually dilated to sternite 5 which is almost completely yellow. Also, very narrow anterior margin and extensive median parts of sternites 2–4 yellowish.Abdominal pile inconspicuous, mostly yellowish but partly black on dorsal black areas.

Terminalia. Male terminalia brownish to black with yellow cerci. Proctiger relatively narrow, slightly shorter than cerci, epandrium subtriangular, rounded posteriorly and distinctly emarginate anteriorly. Medial process of genital capsule bipartite, both parts relatively narrow, somewhat hook like and pointed distally, separated by unusually deep and narrow middle incision. Gonocoxites with long, pointed outer distal process as found in many other species of Nemotelus . Tripartite aedeagal complex slender and long, both lateral parts appressed to central tube, with small and dense marginal spines, two asymmetrical ventral spines unusually long.

Length. Body 6.5–6.7 mm, wing 5.7–5.8 mm.

Female. Head without pale frontal spots and with broad, almost parallel-sided frons. Rostrum slightly shorter than horizontal diameter of eye (1: 1.2). Head pile silvery white, small, elongate postpronotal lobe ochre yellow, reddish brown upper margin of anepistenum narrow. Darkening of legs limited to middle third of femora, tibiae ochre yellow but hind tibia with a slight medial ring or completely yellow. Abdomen black with narrow yellow lateral margins, slightly expanded posteriorly on tergite 4, dorsal medial spots barely distinct on tergite 2, brown and reddish brown yellow lateral margin extended along posterior margin of tergites, round on tergite 4. Sternites 2 and 3 with transverse yellowish spots in middle.

Length. Body 6.4 mm, wing 6.5 mm.

Etymology. The species is named in honour of Prof. Emilia P. Nartshuk (Zoological Institute of the Russian Academy of Science, St. Petersburg), who elucidated the identity of many species of Nemotelus described by Theodor Pleske lations of this species and its variability were examined by ROZKOŠNÝ (1977, 1983, 2000). According to present knowledge the distinguishing characters of this species (especially the male terminalia) are relatively stable and clearly defined (see Tab. 1).

Figures

Figs 1–9. Nemotelus nartshukae sp. nov. 1 – male head, lateral view; 2 – female head, lateral view; 3 – female head, dorsal view; 4 – antenna; 5 – male abdomen, dorsal view; 6 – female abdomen, dorsal view; 7 – dorsal part of male terminalia; 8 – ventral part of terminalia, with aedeagal complex, dorsal view; 9 – aedeagal complex, ventral view.

Figs 17–20. Nemotelus nartshukae sp. nov, paratypes, abdomen detached. 17 – male, lateral view; 18 – male, dorsal view; 19 – female, lateral view; 20 – female, dorsal view. Both specimens without abdomen. Photos by I. Malenovský.