Brief SummaryRead full entry
Onthophagus acuminatus is a small black dung beetle that belongs to the Scarabaeidae family. These diurnal beetles are found in the understory of the tropical lowland and foothill forests of Central America (Emlen 1996a). There are two distinct morphologies among males of this species. Large males have two large conical horns that extend from their prothorax. Small males have reduced horns or none at all. These horns serve as weapons for intraspecific competition (Emlen 1997b). Males use their horns, or lack of, to either defend female brood tunnels (where female O. acuminatus prepare a nest) or sneak into the tunnels via digging. (Emlen 1997b) Females have no horns.
O. acuminatus depends on howler monkey dung for all stages of their life cycle. Females dig brood tunnels at the bottom of which they compact tight dung balls to lay their eggs in. These dung balls supply food for the larvae up until adulthood (Emlen 1996a). When the adult O. acuminatus beetles emerge from the tunnels they fly through the understory searching for dung (Emlen 1997b). Upon arrival to said dung, both male and female individuals feed on dung of a “soupy” consistency, and then start the cycle over again (Ridsdill-Smith 2003). There are no specific predators reported for O. acuminatus.