After months of trials, a contender for the title of World's Strongest Insect was named by scientists yesterday.

The dung beetle species Onthophagus taurus can pull a load 1,141 times its own body weight - the equivalent of an average person pulling six fully-laden double-decker buses.

Dr Rob Knell, one of the researchers from Queen Mary University of London, said: "Insects are well known for being able to perform amazing feats of strength, and it's all on account of their curious sex lives.

"Female beetles of this species dig tunnels under a dung pat, where males mate with them. If a male enters a tunnel that is already occupied by a rival, they fight by locking horns and try to push each other out."

Dr Knell's team tested the ability of beetles to resist a rival by measuring how much force was needed to pull them from their holes.

The findings are published in the journal Proceedings of the Royal Society B.

Dr Knell said: "Interestingly, some male dung beetles don't fight over females. They are smaller, weaker and don't have horns like the larger males. Even when we fed them up they didn't grow stronger, so we know it's not because they have a poorer diet.

"They did, however, develop substantially bigger testicles for their body size. This suggests they sneak behind the back of the other male, waiting until he's looking the other way for a chance to mate with the female. Instead of growing super-strength to fight for a female, they grow lots more sperm to increase their chances of fertilising her eggs and fathering the next generation."