Adult beetles are 5 mm long and 3 mm wide (approx. one third the size of a worker bee). After the beetle emerges from the soil, it might be coloured reddish brown, but it darkens rapidly to brown or black. The body is divided into three parts: head, thorax and abdomen. Characteristic features of adult beetles are the “club-shaped” antennae and the short elytra, which are smaller than the abdomen, so the end of the abdomen is expose.
The larva is the developmental stage that is harmful for the bee colony. The larvae grows up to 1 cm long, is coloured creamy white and might at first sight be mistaken for the larva of the greater wax moth (Galleria mellonella). However, on closer examination it can easily be distinguished from the latter by its three pairs of prolegs, characteristic spines on each body segment down the length of its back and two large spines at the back end.