Melolontha melolontha, a British member of the Scarabaeidae family

In the Scarabaeidae subfamily Scarabaeinae the principal food stuff is dung, although some species eat carrion, rotting fruit or fungus. In a recently published paper one Peruvian species in the Scarabaeinae subfamily, Deltochilum valgum, has been found to be a predator of millipedes (Larsen et al, 2009).

In comparison to other dung beetles, D. valgum has a modified head, hind legs (the tibiae) and abdomen (pygidium), which makes it suited for attacking and feeding on millipedes. The beetle uses part of its head, the clypeus, as a lever to prise apart segments of a millipede’s body, often resulting in decapitation.

To test food preference the experimenters used a variety of bait traps containing dung, carrion, fungus, fruit and millipedes. They found that D. valgum was only attracted to millipedes and that it preferred millipedes which were injured but still alive.

Thanks to Linda for showing me a BBC News article on this. Irritatingly the BBC had inadequately referenced the study, so it took me a little while to find the actual article.

References:

Larsen, T.H., Lopera, A., Forsyth, A. and Génier, F. (2009) From coprophagy to predation: a dung beetle that kills millipedes. Biology Letters, 20th January [Online] Available at:

http://journals.royalsociety.org/content/g17124g4q8733365/

[Accessed 21st January 2009]