Chalcosyrphus eunotus (Loew, 1873) (figs 3–4) M a t e r i a l e x a m i n e d. Ukraine: Kyiv Region: Potashnia env., 50.71 N 29.73 E, Tal River floodplain, 21.05.2015, 1 ♂ (A. Prokhorov); Irpin env., 50.51 N 30.26 E, mixed forest, 11.05.2011, 1 ♂, 28.04.2012, 1 ♂ (M. Zaika); idem, mixed forest along railway, on trunk of Quercus robur, 11.04.2017, 1 ♀ (A. Prokhorov). D i s t r i b u t i o n: Britain, Netherlands, Belgium, France, Germany, Czech Republic, Slovakia, Switzerland, Hungary, Poland, Romania; in southern Europe from northern Spain, southern France, Croatia, Macedonia, Serbia, Armenia, the Caucasus and Turkey (Holinka & Mazánek, 1997; Vujić & Milankov, 1999; Speight, 2016). Ukraine (first record). Our records are on the eastern border of the range of this endangered saproxylic European- Caucasian species. Notes. A rare hoverfly associated with a very strict habitat niche (semi-submerged logs in woodland streams), this species is threatened in many countries in Europe (Jukes, 2010 b; Soszyńska-Maj, Soszyński & Klasa, 2009; Speight, 2016; etc.). Maibach & Goeldlin de Tiefenau (1992) reared one larva of this species from a container with wet sawdust placed beside a stream in Fraxinus woodland. According to other data the larvae made tunnels in the wood of the small Alnus and Betula logs partly submerged in water, on the margin of a small stream within riverine gallery woodland (Jukes, 2010 a, 2010 b, 2011; Speight, 2016). Soszyńska-Maj et al. (2009) advance the hypothesis that the increasing occurrence of C. eunotus in Poland is directly proportional to increasing in the number of beavers over the last 20 years.

Published as part of Prokhorov, A. V., Popov, G. V. & Zaika, M. I., 2018, New Records Of Hoverflies (Diptera, Syrphidae) From Ukraine. I. Milesiini And Rhingiini, pp. 13-20 in Vestnik Zoologii 52 (1) on page 15, DOI: 10.2478/vzoo-2018-0002, http://zenodo.org/record/6404156