Sean Stankowski

Why Are Dung Beetles So Horny?

Both sexes of the Sri Lankan dung beetle Onthophagus sagittarius have horns, but while the males use theirs to fight over females, entomologists remain puzzled about the role of the much larger female horns (left). Reporting online today in the Proceedings of the Royal Society B, a team of researchers suggests that females also use their horns to fight, but over a different prize. When the scientists limited the supply of dung to the insects, they found that larger-horned females produced more offspring than other females of the same size. The study authors suggest that females lock horns and fight like sumo wrestlers, enabling larger-horned beetles to grab a greater stash of dung. Since the females lay their eggs inside carefully constructed balls of dung, more dung means more offspring.

Posted in Environment