Cheilosia reniformis Hellén, 1930

Prokhorov, A. V., Popov, G. V. & Zaika, M. I., 2018, New Records Of Hoverflies (Diptera, Syrphidae) From Ukraine. I. Milesiini And Rhingiini, Vestnik Zoologii 52 (1), pp. 13-20 : 17

Cheilosia reniformis Hellén, 1930 ( figs 12–14 )

M a t e r i a l e x a m i n e d. Ukraine: Zakarpattia Region , Kamianytsia env., 48.70 N 22.43 E, Uzh River valley (left bank), 6.05.2017, 1 ♀ (A. Prokhorov) .

D i s t r i b u t i o n: “from Norway …; Finland; the western edge of European Russia and eastern Asiatic Russia (Yakutia) … also to an isolated, montane, Serbian population of what may be this species, pointing out that, while genetically this population is more similar to C. reniformis than to other elements of the C. vernalis complex, it might equally represent a distinct and as yet unnamed species” (Speight, 2016). In the Catalogue of Palaearctic Syrphidae ( Peck, 1988) this species was recorded for Russia only from West Siberia, but Mutin & Barkalov (1999) provided the new data on the species range in the West Palaearctic: Siberia, south of Khabarovsk Region, Amur Region, Sakha Republic (Yakutia), and Irkutsk Region. Ukraine (first record). Such a record of this boreal species, relic in the nemoral part of Europe, is the second since the Serbian records ( Ståhls et al., 2008).

Diagnosis. Female: Head ( fig. 14 ). Face black, weakly dusted and mostly shining, with facial tubercle and lower facial margin well developed ( fig. 13 ); frons shining with short pale pile (black hairs present only before anterior ocellus), vertex shining with black hairs; basoflagellomere reddish, almost circular, arista almost bare, uniformly dark; eyes with short and very sparse whitish pile, lower part of eyes bare ( fig. 14 ). Scutum and scutellum black and shining, with fine punctuation and short pale pile (hairs almost erect in our specimen), black bristles on hind rim of scutellum absent, but short bristles present on postalar calli; anterior anepisternum dusted, posterior anepisternum weakly dusted only at upper and posterior part, the rest is shiny; upper and lower hair spots on katepisternum widely separated; halter knob yellowish. Wing hyaline with yellowish tint and yellowish stigma. Legs: femora black with black bristles on apical half of ventral sides, its small apical part pale, tibiae pale with black rings below middle ( fig. 13 ); tarsomeres of all legs blackish on the upper side, only basitarsus of mid legs yellowish (as the apex of the tibia). Abdomen round, as long as wide, only with pale pile, hairs in the middle of tergites are very short. Body length 7 mm.

It differs from C. melanura Becker, 1894 by tibiae mainly pale, hind tibia with black ring over less than half its length (in C. melanura tibiae mainly black, hind tibia with black ring over more than half its length), scutum and scutellum with only pale hairs (in C. melanura with many black hairs). From C. chloris (Meigen, 1822) differs by arista uniformly dark (in C. chloris arista reddish in base), bristles on postalar calli present (in C. chloris bristles on postalar calli absent), body length 7–8 mm (in C. chloris 8–11 mm). From C. bracusi Vujić & Claussen, 1994 C. reniformis differs by hind tibia with most developed black ring and small body (in C. bracusi hind tibia with narrower black ring, body length 11– 13 mm). Differences from C. fraterna in key by Van Veen (2010) indistinct, C. reniformis with extremely short hairs on thorax ( C. fraterna with short erect hairs), and size of the body smaller (in C. fraterna 8–10 mm). By Bartsh et al. (2009), thorax of C. reniformis covering with extremely short and slightly decumbent hairs. Specimens of C. reniformis with bristles on hind margin of scutellum differs from C. vernalis (Fallén, 1817) ( figs 15–17 ) by very short hairs (virtually hairs are absent) on lower part of eye (in C. vernalis hairs are uniformly length over the entirely surface of an eye, fig. 17 ) (Speight, 2016), and eyes with only white hairs (in C. vernalis upper part of eyes with dark hairs, fig. 17 ). As additional differences we can mention the following: in C. reniformis pale hairs on thorax are whitish (in C. vernalis they are yellowish, fig. 16 ), posterior anepisternum in C. reniformis distinctly dusted at upper and posterior part (in C. vernalis mostly shining).

Figures

Figs 12–17. Females of Cheilosia reniformis (figs 12–14) and C. vernalis (figs 15–17): 12, 15 — habitus, dorsal view, 13, 16 — habitus, lateral view; 14, 17 — head, anterolateral view.