Onthophagus taurus, (Schreber, 1759)

Alekseev, Vitalii I., 2018, Scarabaeoidea (Insecta: Coleoptera) Of The Kaliningrad Region (Russia): The Commented Actual Checklist, Assessment Of Rarity And Notes To Regional Protection, Acta Biologica Universitatis Daugavpiliensis 18 (2), pp. 111-152 : 133-134

53. O. taurus (Schreber, 1759)

Lentz 1879; Bercio & Folwaczny 1979; Alekseev & Nikitsky 2008.

Voucher specimens: 3 [the Baltic Spit, 19 July 2005, 2 exp.; Baltiysk, 25 May 2008].

Kaliningrad Region: Gur. (Königsberg, Wilkie), Nest. (Rominten), Zel. (Frische Nehrung, Neuhäuser, Pillau); Zel.

Comments: Heliophilous occasional species, currently localized in south-western part of the Region on sandy coasts of Baltic Sea in cattle dung. The occurrence in the Kalinigrad Region and in Lithuania is the northernmost localities of the species in the eastern Baltic region. According to Kabakov (2006), the northern limit of distribution range is the line between Kaliningrad and Smolensk, i.e. reaching to 54˚40ʹ north latitude. This European species is considered regionally extinct in England and in Mecklenburg-Vorpommern, north-eastern Germany ( Rössner 2013), but is succefully introduced in North America in the 1970s and now occurs in Florida and Michigan, United States of America ( Floate et al. 2015).

The beetles are collected in cattle excrements on the Baltic seaside. All male specimens found in the Region during research belong to forma media (with the short and weakly arcuate horns). Horn development is facultative, and depends on the the attainment of a certain body size (Arrow 1951), which, in turn, depends on the nutrient conditions encountered by males during development and may be regulated hormonally ( Emlen & Nijhout 1999). Males reared on reduced food amounts do not develop horns, irrespective of the morphology of their fathers ( Emlen 1994; Emlen & Nijhout 1999). The exclusively observed forma media should be a characteristic of the unsufficient development conditions for the beetles in the area.