Adult beetles might emerge in the autumn, but the main emergence is in the spring when they mate. Following mating, the females lay their eggs in decaying organic matter, and then die.
Larvae overwinter wherever they have been feeding, that is in compost, manure, leafmould or rotting wood, and they pupate in June/July. Larvae grow very fast, and before the end of autumn they would all have moulted twice. They have a two year life cycle.