The Cromwell chafer is a nocturnal species, active during the spring and summer from August to March. It emerges at night to feed on speedwell (Veronica arvensis), cushion plant (Raoulia australis), sheep's sorrel (Rumex acetosella) and a number of lichens (2). Activity is highest on warm nights when humidity is low, and they tend not to emerge if the temperature is below six degrees Celsius. (2). In the day, adults burrow up to half a metre deep in the soil, typically at the base of silver tussock (Poa cita); they tend to return to the same burrow that they used the previous day (2). Studies have shown that females do not disperse, but it is the males that wander in search of females to mate with. Males also tend to emerge earlier in the year than females (3)
Very little is known of the larval stage of this beetle. It is thought that they may be associated with the roots of silver tussock, and that they may take more than one year to develop. Pupae of this species have never been found (3).