Nest construction, fighting, and larval behavior in a geotrupine dung beetle, Ceratophyus hoffmannseggi (Coleoptera, Scarabaeidae)

The female beetle Ceratophyus hoffmanseggi buries dung, with the assistance of a male, to form a series of underground brood masses. An egg is laid in the soil near each mass. Beetles of either sex resist intruders in the entrance to their burrows by a head-to-head pushing contest, without injury to either opponent. The larva feeds within the brood mass forming an elongated cavity. This chamber is lined with a tube built from larval excrement. The larva does not immediately repair holes made in this tube, and can neither isolate itself from another larva introduced into the same chamber, nor maintain a closed chamber when it is placed in a free-standing brood ball.