One of the most famous facts about the praying mantis is their proclivity for sexual cannibalism, with females eager to devour their mates as a post-coitus snack. The extra nutrients gained from consuming their partner is thought to improve the reproductive output of the female, although the males would probably prefer them to sate their hunger with a tasty fly instead of their corpse. These femme fatales sometimes get ahead of themselves and eat the males before – or even during – the act. This macabre behavior typically favors a cautious approach for the males, but a new study published in Biology Letters details a species where males have a more violent approach to mating successfully.
Researchers from the University of Auckland in New Zealand collected Springbok mantises (Miomantis caffra) from across Auckland and observed what happened when they placed virgin males and females together in an upturned plastic cup. They found that the males and females wrestled with each other, battling to grip each other with their raptorial forelegs. Which party won this duel for dominance had big implications, with either copulation or certain death as the outcome.
The females were fed flies the night before the males were introduced to their cups so they didn’t chow down on the unlucky specimens out of pure hunger. The males were always the first to initiate contact, leaping onto the female with their wings fluttering rapidly. In 90% of these cases, this escalated to a full-on brawl, lasting an average of 12.77 seconds. The female was the victor 35% of the time, which always ended with the male being feasted on. Males emerged as the winner 58% of the time, and 67% of these victories ended in mating. However, this did not spell survival for the males, with half of the matings ending in cannibalism anyway, and 13% of the so-called winners being eaten without even getting any action. No winner was established in 7% of the wrestling matches.
You can witness one of these sexual smackdowns in this video:
The researchers theorize that the Springbok mantis does this, rather than the more typical timid approach of other mantids, for two reasons. The first is the fact that 60% of sexual interactions for this species end in the male meeting an untimely demise at the hands of the female. The second is that males and females of this species are fairly similar in size, giving the males a better chance of besting their female counterparts in combat. Over a quarter of the females observed received injuries when the claws of the male pierced their abdomen, creating wounds that oozed hemolymph and formed a black scar. However, the fairly low rate of injury led the researchers to believe that these injuries were not intentional, rather an unfortunate consequence of this brutal mating behavior.