why do praying mantises eat their mates

Female praying mantis eat their male partner after sexual intercourse as it may increase their fertility and ensure the potential survival of the species, scientists have said. They believe that from an evolutionary perspective, male praying mantis may actually benefit from being eaten. In their study,
the authors decided to investigate what purpose 'sexual cannibalism' serves in the survival of the species. In nature, male mantises are eaten by females in about 13 to 28% of sexual encounters and during the mantis mating season, males can make up as much as 63% of the female diet. t more eggs were laid by females who engage in acts of 'sexual cannibalism'. parents. More amino The scientists used a species of praying mantis known as Tenodera sinensis to study the practice of sexual cannibalism among the insects.

Males were fed crickets doused with traceable radioactive amino acids - the building blocks of all the proteins in the body. They were then allowed to mate with females. Half of the twenty-one pairs progressed to sexual cannibalism while the other half were prevented from turning to cannibalism by the scientists. In the bodies of females and in the eggs they laid, the scientists traced back how much of the male amino acids could be found. They discovered that eggs and reproductive tissues of cannibalistic females contained significantly more male-derived amino acids than those of non-cannibalistic females. About 89% of amino acids from eaten males were found in their females. Males who escaped being eaten however were only able to pass on about 25% of their amino acids acids via ejaculation.

There was also an increase in the number of eggs produced subsequent to sexual cannibalism - suggesting the practice increases fertility. Females who ate their partners produced on average just over 88 eggs, compared to an average of 37. 5 for those who did not. More research needs to be carried out on a larger number of mantis but already, the scientists say their work supports the theory that sexual cannibalism marks the ultimate form of male parental investment in offspring. Claim: Female praying mantises always eat the heads of their mates. Example: [Newsday, 1993] Origins: For a long time it was believed that not only did the female praying mantis consume the head (and sometimes the rest) of her mate during copulation, but that this grisly act was a necessary part of the reproductive process. (The reasons given for this act of decapitation included its being a signal to the male to release his sperm, its providing the female with protein required for her to produce more eggs, and its being a way of keeping the male from leaving prematurely. ) Even though the notion that the female always eats her mate has long since been disproved, the legend of the always-deadly female persists.

In a research project whose results were published in the journal Animal Behaviour in 1984, entomologists Eckehard Liske and W. Jackson Davis made videotapes of the sex lives of thirty pairs of praying mantises.

They discovered that mantises engage in elaborate posturing rituals before mating, but not one of the thirty males had his head eaten during the mating process. They also noted that other scientists had observed the same thing: Although female mantises sometimes ate their mates, the deadly act by no means occurred in every case. The behavior appeared to be influenced by captivity: Female mantises were either jarred into unusually aggressive behavior by the unusual laboratory conditions, or they were simply not fed enough by their keepers. Yes, the female praying mantis does sometimes eat her mate. In fact, male mantises will often offer themselves up as food to the female during the mating process, and from a biological standpoint this action makes sense: There's no point to mating with a female who might die from a lack of food before she can lay her eggs and pass the father's genes onto the next generation.

This doesn't happen all the time, however, and its frequency of occurrence and the reasons for it are still a subject a debate within the entomological world. Last updated: Liske, E. and W. J. Davis. "Sexual Behavior of the Chinese Praying Mantis. " Animal Behaviour (32:916-917, 1984). Chapple, Steve. "Bugz: Everyone Has a Scorpion-in-the-Ear Story. " Sports Afield. 1 August 1997. Raver, Anne. "Ants in Your Pants? Nope, They're Dozing Underground. " Minneapolis Star Tribune. 7 November 1996. Teyssier, Jean Claude and Dan Schneider. "The Devil's Riding Horse. " Canadian Geographic. 17 July 1997.