Dorcinae Parry, 1864

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 : 121

Subfamily Dorcinae Parry, 1864 Genus Dorcus MacLeay, 1819

6. D. parallelepipedus (Linnaeus, 1758)

Bercio & Folwaczny 1979; Alekseev & Sakhnov 2000.

Voucher specimens: 11 [Dolzhanskoe, June 1999, 2 exx; Otradnoe 03 July 2007; railway station “ 1312 km ”, 19 May 2009; Yantarny, 24 May 2010; ibidem 21 May 2014; Mechnikov, 11-25 May 2016; ibidem, 21 June – 06 July 2016; ibidem 04-23 May 2017; ibidem, 02 July – 09 August 2017; railway station “ 1312 km ”, 08 May – 22 July 2018].

Kaliningrad Region: Chern. (Insterburg), Gur. (Königsberg, Wernsdorf), Zel. (Galtgarben, Neuhäuser, Rauschen, Warnicken); Bagr., Chern., Gur., Gvard., Krasn., Nest., Pol., Zel.

Comments: This widely distributed and occasional in the Kaliningrad Region species occurs in old parks and forests, especially in western parts of the Region. The species develops in rotten stumps and logs of old deciduos trees (mainly Quercus and Fagus ). Beetles feed on effluent oaken sap. The human settlements and suburbs are not avoided (e.g. the species is encountered regularly in Kaliningrad in 2010-2018) if the sufficient amount of the dead wood is leaved. The species is listed in the supplement to the Red Data Book of the Kaliningrad Region ( Dedkov & Grishanov 2010) as the required especially attention beetle. The species is considered “least concern” at the European level ( Nieto & Alexander 2010). The populations of the beetle are stable now, the species dont belong to threteaned at the regional level.

The majority of male specimens from the Region evidently belong to forma major (possessing inner denticle on mandibles). The largest measured male specimen is totally 30 mm long including mandibles (body length is 26 mm, open mandibles are 4 mm long); the smallest male specimen is 18.5 mm long (f. minor, body length 17 mm, closed mandibles are 1.5 mm long, with short and rounded inner denticle). The smallest measured female has 16 mm total body length. The statistic analyse like made by Hendriks (2013) was not performed due to small number of collected specimens, but the length variation in randomly sampled beetles and registration of such large specimen in the studied area can characterize environmental conditions for this species in the Kaliningrad Region.