Melanogaster tadzhikorum ( Stackelberg, 1952 )

Popov, Grigory V. & Prokhorov, Alexey V., 2020, Revision of the Melanogaster jaroslavensis group (Diptera: Syrphidae), with description of a new species from Afghanistan, Zootaxa 4743 (4), pp. 536-552 : 544

Melanogaster tadzhikorum ( Stackelberg, 1952)

Figs 4 G–I; 5C

Chrysogaster tadzhikorum Stackelberg, 1952: 363 . Type locality: Tajikistan [LT ♂ ZIN]

Chrysogaster tadzhikorum: Stackelberg (1959: 901) , Peck (1988: 135), Richter & Kuztentsov (2007: 21)

Melanogaster tadzhikorum: Maibach et al. (1994 a: 230)

Melanogaster tadzhikorum: Maibach et al. (1994 b: 268) , Vujić & Stuke (1998: 346)

Material examined. Lectotype, ♂ [ Stalinabad (= Dushanbe), Tajikistan, 28.IV.1942, Gussakovsky leg.] . Paralectotypes: ♀ [ Peter the Great Range, Kamchirak Pass ( Tajikistan), 26. VI.1911, Golbek leg.] , ♂, ♀ [ Katta-Ming , Kattakurgan District, Samarqand Region ( Uzbekistan), 24.IV.1923, L. Zimin leg.] , ♂, ♀ [ Stalinabad , Tajikistan, 15.IV.1942, Gussakovsky leg.] , 3♀♀ [ Stalinabad , foothills, Tajikistan, 22, 24, 26.IV.1942, Gussakovsky leg.] , 2♀♀ [ Stalinabad , Dushambinka River valley ( Tajikistan), 13. V.1943, Stackelberg leg.] , ♀ [ Varzob , Gissar Range, Ta- jikistan, 1. V.1944, Stackelberg leg.] , 4♀♀ [ Ziddy , S slope of Gissar Range, Tajikistan, 15, 16. VI.1944, Stackelberg leg.] .

Diagnosis. Body length: 6.3–7.4 mm. Body from dark olive to greenish black, shiny. Facial tubercle well developed but less than in M. jaroslavensis and M. kirgisorum . Hypandrium similar to M. hirtella species-group, epandrium typical for M. nuda species-group (see Kassebeer, 1999 a). Melanogaster tadzhikorum male is most similar to the male of the new species, but can be separated from it by: frons covered with pale and dark pile; face and frons narrower; facial tubercle more protruded; surstyli almost straight laterally in ventral view. Both M. tadzhikorum and the new species females are characterized by a very broad frons (ratio of the maximum head width to the frons width at the level of the antennal base 1.7–1.8, ratio of the maximum head width at the level of the antennal base to the vertex width 2.6–2.7), but M. tadzhikorum female can be distinguished from that of the new species by the 5–6 clearly developed transverse furrows on the frons laterally. Like the new species, M. tadzhikorum can be distinguished from M. jaroslavensis and M. kirgisorum by the same features.

Redescription. MALE ( Fig. 4 G–I). Body length: 6.4–7.4 mm. Head ( Fig. 4G, H ). Eyes bare, eye contiguity length equal to frons length. Frons convex with pit in front third, black, shining without pollinose or with weak greyish pollinosity, upper part covered with long dark brown to black pile. Frons and face broad, ratio of the maximum head width to the frons width at the level of the antennal base 2.1–2.2. Face with weak greyish pollinosity in upper half and shiny black in lower half. Facial tubercle weakly developed. Mouth-edge protrudes forward more than facial tubercle. Lateral sides of face with weak transverse wrinkles and with sparse long white pile. Vertical triangle black, faintly shiny, with pale pile. Occiput black with dark greyish pollinosity. All antennal segments black. Basoflagellomere rounded, arista bare. Thorax. Mesonotum and scutellum shining black, sparsely finely dotted with long pale yellowish pile (length equal to basoflagellomere diameter). Mesopleura matt black, grey pollinose, anepisternum and anepimeron with pile as on mesonotum. Legs black with pale pile. Wing. Length 5.2–5.5 mm. Almost hyaline, entirely microtrichose, clearly yellowish basally, as well as veins yellow near base but brownish apically; pterostigma yellow; vein M joining vein R 4+5 at right angle; calypter whitish with yellowish edge; halter stem light greyish-brown, knob dark. Abdomen. Shining black, tergites II–III above and triangle spot in front half of tergite IV velvet black. Tergites covered with short yellowish white pile dorsally, long on sides, sternites covered with long yellowish white pile. Genitalia ( Fig. 4I ). Surstyli relatively short and almost rectangular in lateral view, with small hook-like process on apex, weakly emarginated apically in ventral view, almost straight; cerci triangle in dorsal view.

FEMALE ( Fig. 5C ). Body length: 6.1–6.5. Similar to the male except for sexual dimorphism, and differing by somewhat smaller body size, shorter body pilosity and the following characters. Head ( Fig. 5C ). Ratio of the maximum head width to the frons width at the level of the antennal base 1.7–1.8, ratio of the maximum head width at the level of the antennal base to the vertex width 2.6–2.7. Frons broad and roughly dotted with 5–6 transverse furrows from each side, with short white pile. Mouth edge clearly prominent. Thorax. Mesonotum with short erect whitish pile. Wing. Length 5.5–5.7 mm, yellowish. Abdomen. Tergite V with straight edge. Sternites brightly shining.

Distribution. Afghanistan, Kyrgyzstan, Tajikistan, Uzbekistan ( Peck, 1988).

Biology. The preferred environments are alluvial localities in the mountain areas at altitudes from 800 to 2000 m ( Stackelberg, 1952, 1959; Peck, 1968). Adults fly in spring and summer (15.IV–26.VI). The flowers visited are Berberis sp. and Umbelliferae ( Peck, 1968). The larva is unknown.

Figures

FIGURE 4. Male paralectotypes of Melanogaster jaroslavensis (A–C), M. kirgisorum (D–F) and M. tadzhikorum (G–I). A, D, G: Head, frontal view; B, E, H: Head, lateral view; C, F, I: Hypopygium, ventral view.

FIGURE 5. Female paralectotypes of Melanogaster jaroslavensis (A), M. kirgisorum (B) and M. tadzhikorum (C), head, dorsal view.