Diodontus medius Dahlbom, 1844

Olszewski, Piotr, Ljubomirov, Toshko, Wiśniowski, Bogdan, Kowalczyk, Jan Krzysztof & Krzyżyński, Maciej, 2016, New records of the genus Diodontus Curtis, 1834 (Hymenoptera: Crabronidae) from Bulgaria, Montenegro and Poland, with a key to Central and Eastern European species, Zootaxa 4061 (2), pp. 164-172 : 165

Diodontus medius Dahlbom, 1844

(Figs 11, 19, 21, 23, 25, 35, 37)

First record from Poland. Pomeranian Lakeland: Garcz (54°20’48’’N, 18°6’’12’’E) 0 7 VI 2009—1 ♀, leg. J.K. Kowalczyk.

This specimen has been collected at the edge of an oak-hornbeam forest beside byway on former farmland.

The species occurs mainly in Northern Europe ( Finland, Sweden, Northern Russia); it has been also reported from Belarus, France, Spain and Ukraine ( Pulawski 2015).

Adlerz (1904) found that adults and their nests occur in sandy areas. The Polish specimen comes from an agricultural landscape, an escarpment at the edge of a forest.

In Scandinavia Leclercq (1974) recognizes D. medius and D. dahlbomi as separate species, however outside this area these two species are regarded as identical ( Jacobs & Oehlke 1990).