A critical review of the distribution of the endangered European earth-borer beetle Bolbelasmus unicornis (Coleoptera, Geotrupidae), with new records from 13 countries and observations on its bionomy

Abstract

The distribution of Bolbelasmus unicornis (Schrank, 1789) is critically reviewed throughout its range with emphasis on the Czech Republic and Slovakia. The species has been reliably recorded from 377 localities in 19 countries. New records are given from 152 localities of Bulgaria, Czech Republic, Germany, Hungary, Italy, Moldova, Poland, Romania, Serbia, Slovakia, Turkey, and Ukraine. For Germany, the species is recorded for the first time in 54 years. The occurrence of the species in Switzerland is confirmed by two historical specimens from Zürich. The only known historical specimen labelled “Kaukasus” is given, which could originate from Russia, where this species has not been recorded before (however, confusion of the locality label cannot be ruled out). All published faunistic data from across the range are presented here in full, in several cases supplemented by details subsequently obtained by the author. Distribution maps are compiled separately for the Czech Republic and Slovakia, and for the entire range. A separate map is also available for Hungary, where approximately one-third of the known localities are located. Statistical data concerning the flight activity of adults, seasonal dynamics for part of the distribution area, details of records and notes on the bionomy and ethology of the species are provided. Possible feeding strategies for adults and larvae of B. unicornis are discussed, as well as current knowledge of the natural history of various representatives of the subfamily Bolboceratinae. A monitoring method for the species is proposed.

Addenda and corrigenda: Juřena D (2022) A critical review of the distribution of the endangered European earth-borer beetle Bolbelasmus unicornis (Coleoptera, Geotrupidae), with new records from 13 countries and observations on its bionomy. ZooKeys 1105: 1–125. https://doi.org/10.3897/zookeys.1105.81474

“…This map was compiled by manually placing the circles in the grid map used for faunistic research in these countries in standard free graphics software. For the distribution map of Europe, the following time periods are used: pre-1950pre- , 1950pre- -1999pre- and post-1999; the distribution map of the Western Palaearctic representatives of the unicornis species group was compiled using data contained in Krikken (1977), Lodos et al (1999), Petersen et al (2006), Miessen (2011), Miessen and Trichas (2011), Hillert et al (2016), Sommer et al (2021) and Juřena (2022). Both of the latter maps were created using the Google Maps web application by inserting specific GPS coordinates into the system.…”

“…(Reisser 1954-this is the first published mention of this record with the correct name of the collector and the exact number of specimens found, something that was missing in subsequent publications: Hoffmann et al 1955;Franz 1974;Mitter 2000;Schwarz 2008;Juřena 2022); area between Pulgarn und Steyregg, August 1875, 1 ♂ and 1 ♀, A. Mader (Linz) leg., coll. Museum Francisco-Carolinum, Linz (Anonymus 1876-this is the first published mention of this record with the name of the collector and the exact number of specimens found, something that was missing in subsequent publications: Dalla Torre 1879; Schwarz 2008;Juřena 2022).…”

“…The record from the vicinity of Rzhyshchiv in the Kiev Oblast (Juřena 2022) was published again by .…”

“…New records are presented based on material and observations obtained by the author just after his initial study (Juřena 2022) was published. Most significant is the record of B. unicornis from southeastern Belarus, which represents the first reliable record for this country and the northernmost known point of occurrence for the species.…”

“…The primary study on the distribution and bionomy (ecology) of Bolbelasmus unicornis (Schrank, 1789) ( Juřena 2022 ) contained a number of minor errors and shortcomings which are corrected here. Some previously omitted literature data are added, namely by Bertolini (1875) , Anonymus (1876) , Schilsky (1888 , 1909 ), Petri (1910) , Reisser (1954) , and Hoffmann et al (1955) .…”