(59). O. medius (Kugelann, 1792)

Lentz 1853; Lentz 1879 ( vacca L. medius Pz.); Bercio & Folwaczny 1979 ( vacca).

Kaliningrad Region: Gur. (Königsberg, Metgethen, Spittelhof, Wilkie), Nest. (Rominten), Zel. (Cranz, Rauschen).

Comments: The species “ O. vacca L. medius Pz. ” or “ O. vacca L.” is reported from the Region according to Lentz (1879) and Bercio & Folwaczny (1979). In the recent research of Rössner et al. (2010) the former species O. vacca (L.) is considered to consist of two sibling species: O. medius (Kugelann, 1792) occuring further north and reaching at least 54° of northern latitude and O. vacca (Linnaeus, 1767), seemingly to be absent north of 50° latitude. The locality of the O. medius neotype is “Lyck, Ostpreussen” [now Ełk, Warmian-Masurian region, northeastern Poland]. In accordance with mentioned above, in the Kaliningrad Region should be expected only one species – O. medius (Kug.) . Therefore, the species O. vacca (L.) has been removed from the species list and the old data concerning its distribution was used for O. medius (Kug.) .

Formerly widespread in the Region species [“often” (Lentz 1853) or “everywhere common” (Lentz 1879)]. The speceis “ vacca (L.)” is reported in Belarus (Alexandovitch & Pisanenko 1991), Lithuania (Tamutis et al. 2011), Sweden, Denmark (Silfverberg 2010), Latvia (Telnov 2004), the Moscow Region (Nikitsky 2009), but it is very possible, part of these reports really concern O. medius (Kug.) .