It’s hard to get any respect when you eat feces. Maybe that’s why one species of lowly dung beetle has forsaken its namesake for a more glamorous place on the food chain—that of a ferocious carnivore. The species Deltochilum valgum may look like any other dung-roller, but it has adapted to feed on giant millipedes more than ten times its size—for comparison, picture a house cat taking down and subsequently devouring an anaconda.
When rumors of Peruvian dung beetles eating millipedes started floating around, a research team led by Trond Larsen of Princeton University headed to the Peruvian rainforests to see for themselves. After setting up more than 1,000 beetle traps baited with either dung, fungus, fruit, or millipedes in various stages of life and death, they found that D. valgum‘s food of choice is in fact injured millipedes. When D. valgum finds an injured millipede, it uses its powerful hind legs—originally adapted for rolling neat balls of dung—to grasp the millipede’s body. After the millipede finishes flailing about, the beetles uses its sharp teeth to saw between its prey’s body segments, sometimes decapitating it. The corpse is then dragged to a safe location where the beetle devours the soft inner tissue.
How does a species make the jump from scavenger to predator? The scientists note that many dung beetles are attracted to dead insects because of their cyanide-rich odors, so D. valgum‘s carnivorous habits may have developed simply because their ancestors were too impatient to wait for dinner to die. As team member Adrian Forsyth explains to BBC News, “This is a beetle which says: ‘It doesn’t matter if it’s dead or alive, I’m going to eat it.’”
Image: flickr / DavidDennisPhotos.com