Bigger Body or More Sperm? A Dung Beetle Conundrum
A male dung beetle (Onthophagus taurus) Credit: Armin Moczek/National Science Foundation
If Franz Kafka were writing today, he might have chosen an insect other than the dung beetle to represent The Metamorphosis’s despairing protagonist, Gregor Samsa. Dung beetles, it turns out, merit the title “World’s Strongest Insect,” according to a recent study in Proceedings of the Royal Society B. Had Gregor known his own strength, perhaps he could have gotten out of that apartment, if not his existential crisis. Then again, maybe he just didn’t have a sexual outlet to put his power to good use.
Researchers have found that certain males of the dung beetle species Onthophagus taurus can pull 1,141 times their own body weight—that’s like a 154-pound human lifting six double-decker buses, according to the AFP.
The strength has to do with sex (are we surprised?). Some males will fight each other for the right to mate with a female, locking horns and pushing, writes the Telegraph. Smaller and weaker males, on the other hand, forgo pugilism, relying on other, ahem, assets—specifically, "substantially bigger testicles,” according to the Telegraph. "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," said researcher Rob Knell, in the AFP article. This suggests that when their beefy rivals aren’t looking, the underlings swoop in to romance the beetle babe on the sly, “[using] their higher sperm count to up their chances at impregnating her in their single shot,” writes Scientific American.
But honestly, didn’t we know it all along? What a male lacks in brawn, he makes up for in sperm.