The effects of some ecological factors on the life-style of the subsocial necrophagous ball-roller scarabCanthon cyanellus cyanelluswere evaluated by experimental analysis. Survival of offspring cared for by parents was higher than survival of offspring without parental care; the latter were immediately attacked by fungi which prevents larval development. The propensity for food to be attacked during the earlier larval stages is a selective pressure which favours parental care inC. cyanellus. Early mating increased the lifetime reproductive success of females, but decreased their longevity. FemaleC. cyanellusmaintained high reproductive success even when resource availability was uncertain. Furthermore, the longevity of the females increased with an irregular supply of food. The reproductive success of females increased with food of high nutritional quality and decreased with food of low nutritional quality.