Effect of using different types of animal dung for feeding and nesting by the dung beetleOnthophagus lecontei(Coleoptera: Scarabaeinae)

Abstract

Onthophagus lecontei Harold, 1871 is an American dung beetle that feeds on the dungs of a variety of species, perhaps owing to hitherto unknown differences in their effect on its development and survival. We tested whether using different types of dung (exotic and native) for feeding and nesting affects O. lecontei’s progeny. Adult beetles from the field were randomly paired and assigned to horse (Equus ferus Boddaert, 1785), goat (Capra hircus aegagrus Erxleben, 1777; domestic), or wild rabbit (Sylvilagus cunicularius (Waterhouse, 1848); native, endemic) dung under laboratory conditions. The number, mass, and volume of their brood masses, the number of emerged beetles, adult size, and duration of preimaginal stages (egg, larva, and pupa) were evaluated. There were differences for all variables: O. lecontei reared in wild rabbit dung produced more progeny, more brood masses, and larger adult beetles, and offspring remained in each preimaginal stage for a shorter period of time. Onthophagus lecontei is able to feed and nest using all three types of dung, but wild rabbit dung is the most favorable for its development. This suggests the existence of a long-standing association between O. lecontei and this native rabbit and the optional relationships with introduced herbivores; plasticity in reproductive behavior that may be useful when the optimal resource is not available.