Effects of ovarian condition on nesting behaviour in a brood-caring dung beetle, Copris diversus Waterhouse (Coleoptera: Scarabaeidae)

Abstract

Copris diversus Waterh. is a brood-caring dung beetle from Africa, the females remaining in the nest with their brood balls until the young emerge. A technique was developed which allowed access to the nest without interrupting nesting behaviour, so that beetles and nest contents could be observed and dung could be added into or removed from the nest at specific times. At 27°C, if more dung was added to the nest in the first three days after the start of brood care, most beetles continued oviposition. Resorption of the terminal follicle started some time between the third and twelfth days of brood care, and while the terminal follicle was resorbing the beetles did not revert to breeding if supplied with additional dung. Subsequent follicles were also resorbed if brood care was allowed to continue beyond ten days, but their resorption did not impose a lengthy delay in breeding. Oviposition resumed 17 to 21 days after the start of brood care, irrespective of when the dung was added. Development of new follicles following follicle resorption took three to seven days, and thus the resorption of the terminal follicle must have taken about seven to fifteen days.