Cheilosia ( Cheilosia ) bergenstammi Becker, 1894

Bot, Sander, Mengual, Ximo, Meutter, Frank Van de & Skevington, Jeffrey H., 2025, Review of the genus Cheilosia Meigen, 1822 (Diptera: Syrphidae) from the Caucasus, with the description of 14 new species, European Journal of Taxonomy 1023, pp. 1-181 : 28-29

Cheilosia ( Cheilosia) bergenstammi Becker, 1894

Fig. 12

Chilosia bergenstammi Becker, 1894: 462 .

Chilosia bergenstammi – Stackelberg & Richter 1968: 245. — Peck 1988: 98. — Barkalov 1993: 721. — Barkalov & Mutin 2018: 482. — Mengual et al. 2020: 15.

Differential diagnosis

Cheilosia bergenstammi has a pilose eye, bare face, bicoloured legs, posterior margin of scutellum with setae and sterna shiny. Many species of Cheilosia have this combination of characters, but it can be distinguihed from most by the pilosity on the eye: dense in the dorsal half, sparse or bare in the ventral half. The trio C. canicularis , C. himantopus and C. orthotricha usually also have the ventral part of the eye bare or with sparse pilosity only, but these species are larger ( 12–15 mm vs 8–10 mm) and lack setae on posterior margin of scutellum. Very similar to extralimital C. fraterna Meigen, 1830 , but metatibia medially with a distinct black ring ( Fig. 12A) (entirely orange or with only vague black marking in C. fraterna ). See also Prokhorov et al. (2020) for a key to distinguish C. bergenstammi from similar species.

Material examined

Species not collected.

Distribution

Western Palaearctic, within the Caucasus reported from Russia.