A male Springbok praying mantis looking to hook up doesn’t have to worry about a female stealing his heart.
There’s a very good chance she’ll bite his head off, though, and he knows it.
Indeed, 60 percent of sexual encounters between Springboks – one of nearly 2,000 mantis species around the world – end in eating males as a snack.
“Men play Russian roulette when they encounter cannibalistic women,” explains Nathan Burke, an entomologist at the University of Auckland and an expert on praying mantis mating rituals.
All male mantis are extremely careful when approaching a prospective mate. Hard to blame them.
But while most sneak from behind or distract the female with a tasty bite, the Springbok has an entirely different – and previously unreported – strategy for staying alive, according to findings in Wednesday. Biology Letters.
“Under threat of cannibalistic attack, men try to restrain women by detaining them in violent combat,” said Burke, co-author with study colleague Gregory Holwell.
Female praying mantis injured by wrestling with a male. (© Dr Nathan W Burke)
Men who win the lovers’ battle are much more likely to consume the relationship, “which suggests that wrestling is both a mating tactic and a survival tactic,” he added.
The key to victory, according to gladiatorial experiments involving 52 praying mantis pairs, was the first to be noticed.
If the male was faster in the draw and the female with his serrated birds of prey grabbed for legs, he had a 78 percent chance of escaping unharmed.
And when, in addition, the male received a serious but non-fatal wound to the abdomen, he held his head every time.
“I was very surprised to find that males injured females while trying to subdue them for mating,” said Burke. “Nothing like this has ever been seen in praying mantises.”
However, if the female grabbed first, the males were always killed and devoured.
Asexual reproduction
In total, the men came out on top more than half the time in these jousts, which lasted an average of 13 seconds.
Winning the match didn’t automatically lead to mating – the mating followed only two-thirds of the time, and even then, the male ended up in the female’s belly half the time.
The bright green Springbok praying mantis, also known as Miomantis caffra, is native to southern Africa, but has likely spread to New Zealand, Southern Europe and California through the pet trade.
The nutrients gained from a female mantis eating her admirer benefit her offspring as they grow.
Sexual cannibalism – when the female of one species eats the male during or after mating – is also known among spiders, such as the black widow, and scorpions.
Usually, smaller males do what they can to avoid being swallowed up, including playing dead.
But female Springbok mantises have one more trick up their sleeve: the ability to reproduce asexually, or without any help from males.
“They can make clones themselves if they don’t mate,” said Burke.
Having this Plan B fallback raises an interesting question: If females are so good at cannibalizing males and reproducing without sex, how do males survive?
“That motivated me to look so closely at male mating tactics,” said Burke.
Sexual conflict theory, he explained, tells us that men in this situation need to take countermeasures to help them mate and stay relevant.
Sure enough, that’s what the researchers found.
“It’s a fascinating example of how sexual conflict can lead to the evolution of mating tactics that help one sex but hinder another.” The fact is, you don’t have to get bored.
© Agence France-Presse