VI.2013., Isaszeg

In an ordinary late afternoon we left Budapest behind and headed in toward an untouched loess sward on the hills of GödöllÅ‘ to collect beetles with mercury-vapour light. Although the sun was setting, the hot evening promised lots of beetles flying around. Meanwhile my fellows were assembling the collecting equipment I set off to catch up species swarming at dusk.


The hidden steppic grassland of a few acres lying amidst fields was able to avoid being ploughed. The unique beetle fauna of the site has been studied for a long time by the staff of the Duna–Ipoly National Park.

Plenty of tiny beetles were flying around on the slope in the pale light of sunset. Stag beetles and june chafers swept just above my head.

I saw the first Odonteus armiger (Scopoli, 1772) before dark. This minute lamellicorn beetle just as small as a cherry pit develops in the fruiting bodies of subterranean fungi. It flies at dusk low over the ground in open forests and meadows. It is widely distributed but sporadical in Hungary.

A female Odonteus armiger (Scopoli, 1772).


  The even tinier Ochodaeus chrysomeloides (Schrank, 1781) is also assumed to develop in subterranean fungi.

Just as the sun slipped over the horizon beetles whirling in the grass were easier and easier to miss. Despite that, I spotted a larger, light-coloured beetle just before dusk, the very rare and protected Bolbelasmus unicornis (Schrank, 1789), which I had never seen before. According to literature, slow-flying females are looking for subterranean fungi at dusk, while males are chasing them. The peanut-sized males have horns on the head and the pronotum. Adults are able to stridulate. They are occassionally attracted to light traps and can also be caught by pitfall traps.

A really "horny bull" with serious armature ready to fight.

Bolbelasmus unicornis (Schrank, 1789) female.

Amphimallon assimile
(Herbst, 1790).

Light-traps also collected interesting species but observing uncommon beetles under natural
conditions is always something different.

Copyright © 2009. Hungarian Natural History Museum, Department of Zoology, Coleoptera Collection