The praying mantis, an ancient carnivorous insect, is found in a wide area of the globe except the polar regions. At present, more than 2,000 species of praying mantis have been found in the world, and more than 140 species are known to the mainland. These tiny predators are mostly green or brown in shape, with a fan-shaped head, prominent large compound eyes and three single eyes, their flexible necks that can be turned 180 degrees, and the jagged forelimbs are the hallmark of the praying mantis. The body length is generally between 55 and 105 mm.
Praying mantis has only a short life span of one year. They go through three stages: egg, nymph, and adult, and the nymph stage needs to molt 7-11 times before it matures into an adult. The life cycle of the praying mantis is closely related to the changes of the seasons, and the larvae that hatch in the spring need to grow in the summer before they can evolve into adults in early autumn.
After adulthood, praying mantis quickly enters the stage of courtship and mating. At the end of August, it is the time of autumn and the mating season of the praying mantis. Unlike most insects, the courtship ritual of the praying mantis is complex and full of drama.
Males, who may be up to 3 times smaller than females, will first attract the female's attention through visual, vocal and pheromone means. If the female shows an attitude of acceptance, the male initiates a series of courtship movements, such as dancing, waving his forelimbs, showing his wings, etc., for up to two hours, with the aim of showing his health and vitality.
If it succeeds in winning over the female, the male will carefully climb on the female's back and mate with her for 2-5 hours. This is undoubtedly a terrifying adventure for males who are much smaller than their partners. Because after mating, many females will swallow the males in one gulp, starting from the head to the tail.
Why do male and female praying mantis have such a cruel ending? This seems to stem from their low-density living environment. Praying mantis species are scarce in the wild, and it is not easy to find a mate of the opposite sex. Therefore, males must forage for food to maintain their strength in order to seize the rare opportunity to mate, and females also need enough food to give birth to offspring. If the spouse dedicates himself or herself to food, it can be of great benefit to both partners in obtaining adequate nutrition.
It can be said that this love feast is the product of millions of years of genetic inheritance of the praying mantis. It also makes our observers lament the cruelty and mystery of nature - on the road of evolution, life is like a dream, the individual is like a bubble, and only genes are eternal. This phenomenon has aroused the curiosity and questions of many people. Why do females treat their mates so ruthlessly? Over the years, many scientists have carried out research and exploration on this issue.
In the 1980s, two American zoologists, Davis and Ricks, designed a set of experiments to observe the feeding habits of praying mantises. They divided 30 pairs of praying mantis into two groups, one to feed the female mantis and the other to starve the female mantis. It was found that the female and male mantis in the satiety group successfully mated without being eaten. But the female praying mantis in the hungry group immediately nibbled on the male when she saw it, not thinking about mating at all.
What does this mean? It is clear that whether a female mantis eats a male mantis or not depends purely on whether it is hungry or not. When it is extremely hungry, no courtship etiquette will work, and it will just gnaw on it.
Later, some scientists compared the female praying mantis that ate the male praying mantis and the female praying mantis who did not, and found that there was no significant difference in the number and survival rate of their offspring. It can be seen that the female praying mantis eating the male mantis has nothing to do with the succession, but simply to fill the stomach.
In addition to this, there is another reason that is also crucial, and that is the size and personality of the female praying mantis. Female mantis is inherently larger than male mantises, and has an innate bloodthirsty nature. It is agitated at the sight of blood and is highly aggressive, and tragedy can occur when the male mantis's courtship action stimulates it, or if the improper release of pheromones causes its hostility.
Therefore, the female mantis eats the male mantis, which is not only related to its own hunger, but also related to its ferocious temper. This phenomenon may seem cruel, but it contains the wisdom of nature. It reminds us that the wild environment is brutal and every creature is desperate to survive. So why don't male praying mantis resist?
In the animal kingdom, females tend to be larger and stronger than males, and this is especially evident in praying mantises. Studies have shown that female praying mantis are often more than twice as large as male praying mantises, which creates a great danger for male praying mantis when mating.
In order to pass on the lineage, the male praying mantis must be close to the female. They will cautiously approach and wait for an opportunity to clamp the back of the female praying mantis for mating. This is an extremely dangerous process, and the slightest mistake can lead to a female mantis backbite and eat your life. According to statistics, less than 5% of male praying mantis survives this mating.
In fact, often after mating, the male mantis will quickly escape, but due to the size difference, the female mantis is significantly faster than the male. For food, female praying mantis will hunt down males mercilessly. Faced with a female mantis twice its size, the male mantis could not resist at all, so he could only let it be slaughtered.
Recent studies have found that a very small number of male praying mantis will fight back in order to survive. A 2021 study by the University of Auckland in New Zealand showed that about 40% of male praying mantis can evade the pursuit of females. Some male praying mantis will distract females during mating, increasing their chances of escape by up to 78%. There are also a few males who will slam the female in the abdomen with their forelimbs, and the seriously injured female is unable to fight back, and the male mantis survives.
But the probability of a successful counterattack is very low, and most male praying mantis are still at the mercy of others. Females are much larger than males and instinct drives them to eat males for food. The male praying mantis is powerless to resist in the face of the female's attack, and can only sacrifice himself to complete the transmission of life, which can be described as a victim of the laws of nature.
According to evolutionary theory, species exist to pass on genes, not for the benefit of individuals. From this point of view, the male praying mantis being eaten by the female is also a means of achieving population continuation at the expense of individuals.
Male praying mantis is much smaller than females and is the result of long-term evolution. The small body size is more suitable for rapid transfer and hiding, which is conducive to male praying mantis approaching females for mating. At the same time, the small size also means that males need less food than females to grow, and have less impact on the population's food chain.
From the point of view of the survival of the population as a whole, it is more important to ensure the number of female individuals. Although each male mantis wants to live as an individual, from a broader perspective, the sacrifice of the individual to ensure the continuation of the species is also the result of evolutionary selection. Of course, this does not justify the female praying mantis mercilessly eating the male. But in the state of nature, every living being struggles to survive in a cruel environment, and there are no moral constraints, only survival instincts.