Buzz
Imagine if a quarter of your friends who were sexually active ended up being eaten—you might think twice about pursuing romance. But for male praying mantises, this grim fate doesn’t deter them. Scientists have long been baffled by their willingness to risk death during mating. A 2016 study, published in Proceedings of the Royal Society B, suggests a surprising explanation: being consumed by the female might actually boost the male’s chances of reproducing successfully.
Mating among mantises is nothing short of dramatic. In roughly 25% of cases, the female engages in sexual cannibalism, decapitating her partner mid-act. Remarkably, the male remains undeterred, continuing to mate even as the female consumes him piece by piece. This gruesome process can last for hours.
A tale of true devotion: a female mantis feasting on her mate's genitals. Image Credit: Oliver Koemmerling via Wikimedia Commons // CC BY-SA 3.0
In essence, he is presenting his body as a gift. This act of sexual gift-giving is quite common among insects—male crickets, for instance, create gummy treats for their partners. However, in most cases, the gift-giver isn’t also the gift itself. From an evolutionary standpoint, this behavior is logical: females can use the nutrients to nourish their fertilized eggs, enhancing the offspring’s survival odds. To determine if this applies to mantises, researchers created a controlled environment for their mating experiments.
The experiment began with a romantic gesture: a meal. Researchers fed male mantises crickets treated with radioactive amino acids. These males were then paired with females for mating. Half of the pairs were separated before the females could consume their partners, while the other half were left to experience their macabre ritual.
By consuming their mates, females also ingested the contents of their stomachs. This allowed scientists to trace the radioactive particles and understand how the nutrients were utilized in the females’ bodies.
Interestingly, even males who survived mating contributed to their partners. On average, surviving males transferred 25% of their radioactive amino acids through their ejaculate. However, males who were eaten provided a staggering 90% of their nutrients, which the females then passed on to their offspring.
Being eaten also boosted a male’s reproductive success by increasing the number of eggs laid by his partner. Females who didn’t consume their mates laid around 37 eggs, while those who did feasted produced approximately 88 eggs.
There’s still much to uncover about these fascinating creatures and their somewhat alarming mating behaviors. However, these discoveries make the seemingly reckless enthusiasm of male mantises appear a bit more justified.
