Cheilosia (Cheilosia) pascuorum 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 : 244-245

Cheilosia (Cheilosia) pascuorum Becker, 1894 ( figs 26–29 )

M a t e r i a l e x a m i n e d. Ukraine. Kyiv Region:Mali Dmytrovychi env., 50.22 N 30.52 E, ravine, 23.04.2018, 3 {; Mygalky env.: 50.66 N 29.50 E, mixed forest near Teteriv River floodplain, 28.04.2018, 1 {; 50.655 N 29.495 E, Teteriv River floodplain, 23.04– 6.05.2020, 3 {, 2} (A. Prokhorov) .

Distribution: Austria, Bosnia and Herzegovina, Croatia, the Czech Republic, France, Germany, Greece, Montenegro, North Macedonia, Poland, Romania, central European Russia, Serbia, the Slovak Republic, Sweden, Switzerland ( Bańkowska, 1963; Peck, 1988; Dirickx, 1994; Vujić, 1996; Holinka & Mazánek, 1997; Wolff, 1998; Stănescu & Pârvu, 2005; Mielczarek, 2009 –2020; Vujić et al., 2013; Barkalov & Mutin, 2018; Speight et al., 2018; Speight, 2020; Wakkie, 2020); Ukraine (first record).

Diagnosis. This species belongs to Cheilosia proxima group ( Vujić et al., 2013) and is most similar to Cheilosia balkana Vujić, 1994 in having first flagellomere black to blackishbrown, margin of upper calypter with short pale pile, frons not swollen, abdomen (including pregenital segments) covered in pale macrotrichia ( Vujić et al., 2001). The Cheilosia pascuorum male can be separated from the male of C. balkana by: tergite 3 dull medially (in C. balkana , tergite 3 shiny); vein M 1 meeting vein R 4+5 at right or obtuse angle ( fig. 26 ) (in C. balkana , vein M 1 meeting vein R 4+5 at an acute angle); arista bare ( fig. 29 ) (in C. balkana , arista with short microtrichia); dorsal lobe of gonostylus very broad basally (in C. balkana , dorsal lobe of gonostylus basally narrowed) ( Vujić et al., 2001). From the similar species C. proxima (Zetterstedt, 1843) and C. gigantea (Zetterstedt, 1838) , C. pascuorum can be separated by: abdomen entirely with pale macrotrichia ( figs 26, 27 ) (in others, abdomen partly with black macrotrichia, at least pregenital segments with a few black macrotrichia). Additionally, from C. proxima it differs by its larger size, usually not smaller than 10 mm ( C. proxima is smaller, usually 7–9 mm). Genitalia of these species are different by the shape of the dorsal lobe of the gonostylus ( Vujić et al., 2001).

The genitalia of C. pascuorum have been prepared and compared with figures in Vujić et al. (2001).

Note. This species is regarded as generally endangered in Europe ( Vujić et al., 2001).

Figures

Figs 26–29. Cheilosia pascuorum male: 26 — habitus, dorsal view; 27 — habitus, lateral view; 28 — head, frontal view; 29 —head, anterolateral view.