Cheilosia (Cheilosia) uviformis Becker, 1894

Prokhorov, A. V., Popov, G. V., Shparyk, V. Yu. & Vasilyeva, Yu. S., 2020, New Records Of Hoverflies (Diptera, Syrphidae) From Ukraine. V, Zoodiversity 54 (3), pp. 237-258 : 245-247

Cheilosia (Cheilosia) uviformis Becker, 1894 ( figs 30–35 )

M a t e r i a l e x a m i n e d. Ukraine. Kyiv Region: Kyiv, Muromets Is. on Dnipro River , 50.5058 N 30.5443 E, on flowers of Acer platanoides , 6.04.2017, 1 {, 18.04.2018, 1 {(A. Prokhorov) .

D i s t r i b u t i o n: Belgium, Denmark, Great Britain, Finland, France, Germany, Ireland, Italy, Lithuania, the Netherlands, Norway, Serbia, Slovenia, Sweden, Switzerland ( Peck, 1988; Verlinden, 1991; Maibach et al., 1992; Dirickx, 1994; Vujić, 1996; Nielsen, 1999; Stubbs & Falk, 2002; Pakalniškis et al., 2006; De Groot & Govedič, 2008; Bartsch et al., 2009 b; Reemer et al., 2009; Haarto & Kerppola, 2014; Speight et al., 2018; Speight, 2020; Verlinden, 2020; Wakkie, 2020); Ukraine (first record).

Diagnosis.The Cheilosia uviformis male looks like the males of C. urbana (Meigen, 1822) and C. psilophthalma Becker, 1894 , and it can also be confused with small specimens of C. rufimana Becker, 1894 .

From C. urbana and C. psilophthalma it can be distinguished by: frons densely covered in microtrichia ( fig. 34 ) (in others, frons covered in faint microtrichia, weakly shiny except the edges along the eyes); face almost entirely with fine but distinct pruinescence including the facial tubercle, only lowest edge of face shiny (in others, frons with facial tubercle and upper mouth-edge distinctly shiny, rarely the facial tubercle may also be finely pruinose); all tibiae entirely yellow or with very vague brownish smudge on each side of tibia ( fig. 31 ) (in others, all tibiae yellow with black incomplete ring); abdomen entirely with pale pile, tergites 2 and 3 without short semi-adpressed macrotrichia posteromedially (in others, abdomen usually at least with a few black macrotrichia, tergites 2 and 3 with short semiadpressed macrotrichia posteromedially); sternites 2–4 dull ( fig. 32 ) (in others, sternites 2–4 shiny).

Cheilosia uviformis can be easily distinguished from C. rufimana by katepisternum with upper and lower patches of pile widely separated (in C. rufimana , katepisternum with upper and lower patches of pile confluent).

Morphological characters of our specimens are completely consistent with those in Speight & Claussen (1987: as Cheilosia argentifrons Hellen, 1914 ). Genitalia of both specimens have been prepared and compared with figures in Speight & Claussen (1987: fig. 2 , f, g) and Stubbs & Falk (2002: Plate M, fig. 1 , a–c).

Note. In Great Britain this species is listed under the UK Biodiversity Action Plan and qualifies as Data Deficient ( Ball & Morris, 2014).

Here we offer an updated key to Ukrainian Cheilosia males of the group D sensu Beck- er (1894), which have tibiae with pale parts.

Key to males of Ukrainian Cheilosia species group D (tibiae with pale parts)

1 Katepisternum with upper and lower patches of pile confluent. ................................................................. 2

— Katepisternum with upper and lower patches of pile widely separated. ..................................................... 3

2 Face width at the level of the antennal sockets exceed eye width at the same level. ..................................... .................................................................................................................................. C. morio (Zetterstedt, 1838)

— Face width at the level of the antennal sockets less than eye width at the same level. ................................. ....................................................................................................................................... C. proxima species group

3 Tergites covered in grey patches of microtrichia, which usually look like maculae. ................................. 4

— Tergites entirely black. .........................................................................................................................................5

4 Compound eye with pale pile. ............................................................................ C. semifasciata Becker, 1894

— Compound eye with dark pile. ................................................................... C. fasciata Schiner & Egger, 1853

5 Compound eye entirely pilose (lower part sometimes more sparcely). ...................................................... 6

— Lower part of compound eye bare or with a single pile. ............................................................................. 12

6 Frons densely covered in pale-grey microtrichia ( fig. 34 ) as well as orbital strip (this is clearly visible against the general background of the face); sternites 2–4 dull ( fig. 32 ). ........... C. uviformis Becker, 1894

— Frons shiny or with faint pruinescence (mostly along eye margins), also faintly pruinose on orbital strip; sternites 2–4 shiny. ............................................................................................................................................. 7

7 Compound eye with pale pile; abdomen slender, with almost parallel sides. ............................................ 8

— Compound eye with dark pile; abdomen oval, usually wider. .................................................................... 10

8 Arista with distinct short microtrichia. ................................................................ C. mutabilis (Fallén, 1817)

— Arista seems bare (with very short microtrichia). ......................................................................................... 9

9 Claws with yellow bases. .......................................................................................... C. urbana (Meigen, 1822)

— Claws black. ........................................................................................................ C. psilophthalma Becker, 1894

10 Abdomen with the largest width at the posterior margin of tergite 3; tergite 4 with adpressed short black seta-shape macrotrichia along central axis; legs dark, fore and mid tibiae with weak brown bases and apexes, hind tibia black with indistinct brown base. ............................................ C. carbonaria Egger, 1860

— Abdomen with the largest width at the posterior margin of tergite 2; tergite 4 with erect and (or) semiadpressed macrotrichia along central axis; all tibiae yellow or pale brown with dark ring, or mostly black with yellow or brown bases and apexes. ........................................................................................................ 11

11 Mesonotum black, usually with a bluish tinge, predominantly with black pile; tergite 5 dull in contrast with shiny tergite 4. ................................................................................................ C. cynocephala Loew, 1840

— Mesonotum black, usually without a bluish tint, predominantly with pale pile or with black and pale pile mixed; tergite 5 shiny as well as tergite 4. ................................................................ C. vernalis (Fallén, 1817)

12 Tibiae black with pale parts; tarsomeres of all tarsi black dorsally and laterally. .......................................... ...................................................................................................................................... C. sootryeni Nielsen, 1970

— Tibiae pale with black parts (sometimes entirely pale); fore and mid tarsi not entirely black. .............. 13

13 Scutellum with pile and setae half or slightly more than half as long as scutellum ( fig. 10 ), at that scutellum often without setae; abdomen more oval, distinctly with largest width at the posterior edge of tergite 2 ( fig. 9 ); fore tarsus black ( fig. 12 ) (tarsomeres 1+2 pale laterally and ventrally), mid tarsus black except first tarsomere usually pale ( fig. 13 ); hind tibia with weak, incompletely developed dark ring ( fig. 11 ), which may be reduced. ............................................................................................ C. fraterna (Meigen, 1830)

— Scutellum with pile and setae at least as long as scutellum ( fig. 2 ); abdomen more slender, elongated-oval with almost parallel sides of tergite 3 ( fig. 1 ); fore and mid tarsi with tarsomeres 1–3 entirely pale ( figs 4, 5 ) (first tarsomere of fore tarsus may be darkened dorsally); hind tibia usually with distinct black ring occupying almost half of tibia ( fig. 3 ). ............................................................ C. bergenstammi Becker, 1894

Subtribe Pelecocerina

Figures

Figs 30–35. Cheilosia uviformis male: 30 — habitus, dorsal view; 31 — habitus, lateral view; 32 — abdomen, ventral view; 33 — head, anterolateral view; 34 — head, dorsal view; 35 — head, frontal view.

Figs 1–8. Cheilosia bergenstammi male: 1 — habitus, dorsal view; 2 — habitus, lateral view; 3 — hind femur and tibia, lateral view; 4 — fore tarsus, dorsal view; 5 — mid tarsus, dorsal view; 6 — head, anterolateral view; 7 — head, frontal view; 8 — head, lateral view.

Figs 9–16. Cheilosia fraterna male: 9 — habitus, dorsal view; 10 — habitus, lateral view; 11 — hind femur and tibia, lateral view; 12 — fore tarsus, dorsal view; 13 — mid tarsus, dorsal view; 14 — head, anterolateral view; 15 — head, frontal view; 16 — head, lateral view.