Parental behaviour in Copris lunaris (Coleoptera, Scarabaeidae): care and defence of brood balls and nest

1. Nesting female beetles righted brood balls (so as to replace the egg or larva in the uppermost position) and repaired damaged balls. This behaviour required the presence of an egg or larva in the ball, or of a short-lasting material found just after oviposition. The shape of the ball was also a righting stimulus since artificial ellipsoids were stood on end. 2. Balls containing dichloromethane extracts of C.lunaris brood were righted and repaired. Eggs and larvae of several other Scarabaeidae did not release these responses but were destroyed. 3. Righting behaviour was released when brood was absent from the top of the ball. The beetle then crawled vertically downwards and, if it encountered the displaced apex, a novel rolling action followed which automatically turned the ball towards the correct position. 4. An opening made in the nest was repaired with soil excavated from the chamber floor. Clunaris adults and Aphodius fossor larvae were attacked if they were encountered in the nest.