Courageous mantis males struggle with their female partner to avoid being eaten, a new study reveals.
New Zealand researchers looked at the mating behavior of the highly cannibalistic Springbok praying mantis (Miomantis caffra), a type of praying mantis.
Praying mantises have a reputation for cannibalism, as females often eat males before they have a chance to mate.
But in this particular species, the male and female struggle in a ‘violent battle’ before mating, as each partner tries to be the first to grasp the other with their front legs.
If the female wins, it means near certain death for the male, but if the male wins, it greatly increases the chances of successful mating, often injuring the female.
Rather than avoiding cannibalism by being shy and cautious, men can overcome the threat of cannibalism by “ compulsively wrestling with women, ” say the experts.
60 percent of the sexual encounters between springbok praying mantises – one of nearly 2,000 mantis species around the world – end with feeding on males.
Astonishing video footage shows the noble male demolishing the larger female in the cups in a lab.
Red arrow indicates a healed abdominal wound in a female Springbok mantis after meeting a male
The study provides the first evidence of forced mating in a praying mantis.
“Men play Russian roulette when they encounter cannibalistic women,” said study author Dr. Nathan Burke, an entomologist at the University of Auckland and an expert on praying mantis mating rituals.
It is rare for men to avoid cannibalism through this form of coercion – physically fighting with women for successful mating – and this is the first evidence of this behavior in a cannibalistic praying mantis.
Sexual conflict in the insect world is not that uncommon and usually prefers a cautious or tactical approach.
“But the male Springbok praying mantis is really fighting to achieve its goal and this study shows that this may be its best option in terms of reproductive success.”
Male (top) female (bottom) Miomantis caffra mating in Auckland, New Zealand. The female’s abdomen is visibly protruding while carrying eggs from a previous encounter with each other
The springbok mantis is native to South Africa, but is commonly found in New Zealand after it was first identified there in 1978.
For this study, researchers collected 52 pairs of Springbok praying mantis and observed their behavior in the lab over a 24-hour period.
“All individuals were housed in individual enclosures and received three to five house flies (Musca domestica) three times a week,” write Dr. Burke and his Auckland co-author, Professor Gregory Holwell, in their paper.
“For mating experiments, we mated adult virgin males and females in upturned clear 700 ml plastic cups and observed their behavior.”
They found that 29 of 52 couples (56 percent) resulted in physical contact between the sexes within the first 12 hours.
The male was always the first to make contact and did this by jumping on the female while quickly flapping his wings.
Nearly all – 90 percent – escalated into physical struggles, lasting an average of 12.77 seconds.
Of these, 7 percent resulted in divorce without a winner.
A female specimen of Miomantis caffra lays her eggs. The species is a medium-sized mantid with one of the highest known rates of pre-copulatory cannibalism. More than 60 percent of sexual interactions end in males who are consumed, usually without mating
35 percent of the fighting resulted in the female grabbing the male first, and all that fighting ended in cannibalism.
Men were the first to grab women in 58 percent of the battle.
Of these, 67 percent ended in mating (half of which subsequently ended in cannibalism), 13 percent ended in cannibalism without mating, and 20 percent ended in cannibalism or mating.
On several occasions, women who lost the battle tried to grab attached men, but failed.
Another unusual finding was that 27 percent of the females who lost the battle were injured by the male’s predictive claws.
This resulted in severe puncture wounds in the abdomen that later formed black crusts – something that was also seen in wild females.
Researchers think that the “intimidating and harmful nature” of male wrestling behavior suggests it is a form of “sexual coercion” by which men force women to mate.
“We’ve learned a lot of fascinating biology from Miomantis caffra over the past decade, but this latest work is really great,” said Professor Holwell.
“This is the best example of men fighting back to face the risk of sexual cannibalism.”
The study is published in the journal Biology Letters.