A certain species of dung beetle has been crowned the world’s strongest insect. A male Onthophagus taurus can pull 1,141 times its own body weight — the equivalent of a 70-kilogramme (154-pound) person being able to lift 80 tonnes, the weight of six double-decker buses [AFP]. That power comes in handy not just to roll up a few extra dung-balls, but also to protect mates and stave off potential rivals.
Chronicling the insect’s amazing strength in the journal Proceedings of the Royal Society B, scientists Rob Knell and Leigh Simmons explain that the beetle’s amazing strength is connected to his sex life. These female dung beetles dig tunnels beneath choice pieces of dung in which to lay their eggs. If another male enters a tunnel already occupied by a rival, then the dung beetles duke it out, each male using his immense strength in an attempt to push the other out. Usually, the male that guards the tunnel repeatedly mates with the female inside.
In the study, scientists calibrated the males’ strength by gluing a cotton thread to the beetles’ hard wing-cases, stringing the thread across a pulley, and tying it to a miniature bucket, to which they added drops of water[ScienceNOW]. The dung beetle’s coronation as the world’s strongest insect steals the thunder from the rhinoceros beetle, which can lift up to 850 times its own weight.
The weaker males in this brawny insect community aren’t entirely out of luck, as nature has endowed them with other survival advantages. Knell added that some male dung beetles are smaller and weaker, but do not have to fight for female attention due to their “substantially bigger testicles”. “Instead of growing super strength to fight for a female, they grow lots more sperm to increase their chances of fertilizing her eggs and fathering the next generation” [AFP].
Image: Alex Wild. Two male dung beetles fight for supremacy.
