Prionus coriarius is polyphagous species, developing in rotten wood of deciduous and coniferous trees. Female lays eggs on basal parts of dead trees and the hatched larvae bore into the wood and proceed down into the roots, which are the main food source. If food resources in one root are exhausted the larvae are able to move through the soil to reach nearby roots. After 3-5 years the larvae leave the roots for the surrounding soil and construct a cocoon out of soil particles, the size of a chicken egg. The larvae cocoon in early summer and typically emerge as fully formed adults in July-August; males tend to emerge before the females. You can encounter this remarkable beetle most likely in the afternoon or at dusk around the bases of dead or damaged trees.

Body length:	18 - 45 mm
Life cycle:	at least 3 years
Adults in:	July - September
Host plant:	polyphagous in rotten wood of deciduous and coniferous trees
Distribution:	forest areas of Europe, Turkey, Caucasus, Transcaucasia, Iran and North Africa

The depicted beetle weas collected in Hodonín (South Moravia, Czechia) on July 27, 2013.

Collected by David Navrátil