Did the male mantis in "Black Cat Sheriff" really volunteer to be eaten?

If dating means potentially losing your life, wouldn't it be nice to be single?

For some insects, the answer may be no.

There was a story in the animation "Black Cat Sheriff": The mantis bride ate her groom on the wedding night, leaving no romance at all and only a pile of debris on the ground.

The mantis groom being eaten

Image source: "Black Cat Sheriff"

After an investigation by the sheriffs, they discovered that the truth was that the mantis groom volunteered to be eaten in order to provide nutrition to the mantis bride and give birth to healthy mantis babies.

Seeing this, many people exclaimed, is this true? After mating, the male mantis is not only willing to be eaten by the female, but also beneficial to the male mantis?

Being eaten after mating is actually a "good thing" for male praying mantises?

Let’s look at the above questions one by one. First, for the male mantis, is being eaten by the female after mating more harmful than beneficial, or more beneficial than harmful?

In fact, this question has been answered in "Black Cat Sheriff": female mantises eat their partners after mating in order to supplement nutrition. So is this answer scientifically based?

There is a biological explanation for this. This behavior is called "sexual cannibalism." In fact, this phenomenon exists not only in mantises, but also in some species of Latrodectus .

Female praying mantis eats her mate after mating

Image source: australiangeographic.com.au

According to a research paper published in the Proceedings of the Royal Society, from an evolutionary perspective, the behavior of female praying mantises cannibalizing males after mating may actually benefit males.

To prove the idea that "being eaten is actually good for me," scientists fed crickets with radioactive tags as food to a group of praying mantises, allowing each mantis to be individually tracked using this specific tag.

They then allowed the male and female mantises to mate. After mating, the researchers allowed half of the females to eat their partners, while the researchers interrupted the other half of the females when they were trying to eat the males.

Thanks to the nutrients they gained from eating their mates, females that ate their mates laid an average of 51 more eggs than females that did not cannibalize their mates.

Not only that, through radioactive labels, scientists can also understand how much of the substances in the mantis eggs come from the male mantis. The results are also very interesting. The eggs of females that eat their mates contain more amino acids and other nutrients from males.

Comparison of the number of eggs laid by female mantises that eat and do not eat their mates

Image source: Reference 1

It seems that Black Cat Sheriff is right! The eaten male mantis can really provide more nutrients for the female mantis.

Although it is beneficial, male mantises may not be without complaints

Since the explanation of nutritional supplementation is most likely correct, then it must be true that the mantis groom was willing to be eaten, right?

Don’t tell me, that’s not necessarily true.

Although it is said that "life is precious, but love is more precious", there are probably not many creatures in this world that are willing to die for love. Although the male mantis was eaten, it may not be without complaints.

The suicide note of the Mantis Groom in "Black Cat Sheriff"

Image source: "Black Cat Sheriff"

Scientists have debunked the rumor that "I did it willingly" was mentioned in the suicide note of the mantis groom in the cartoon.

In 2021, a study published in Biology Communications showed us an unknown side of the mating process of male mantises. In order to survive after mating, male mantises will even fight with females.

A male mantis is fighting with a female mantis

Image source: Reference 2

Researchers from the University of Auckland in New Zealand collected male and female mantises and placed them in an inverted plastic cup, allowing them to mate and then observed them. The results were surprising: after mating, the male mantises did not become the nutrition of their partners without complaint, but instead fought back, surviving if they won and dying if they lost!

The male mantis in the video below is an "unlucky guy". Although he won the right to mate, he lost his life.

Video source: Reference 2

From this we can see that the claim that male mantises are willing to sacrifice themselves is not so tenable. After all, it is better to live a miserable life than to die, let alone be eaten alive.

Don't worry, the male mantis' fate of being eaten is not certain.

Seeing this, everyone may feel sorry for the male praying mantis, who has to worry about being eaten after getting married.

In fact, there are indeed cases where male mantises are eaten, and there are also cases where male mantises resist in order to avoid being eaten. But what you may not know is that the fate of male mantises being eaten is not certain!

In the 1950s, scientists conducted experiments while controlling the diet of female mantises and found that when they were very hungry, females were more likely to attack their partners, but if the female mantises were fed before mating, the male mantises would mostly survive.

so…

For a male mantis, the right thing to do is to find a partner that is well fed!

Sexual cannibalism may seem cruel to humans who have already formed moral and ethical norms, but for nature it reflects the wisdom of survival. We must adapt to nature, respect nature, and get inspiration from nature. As for the male praying mantis, we can only say: uh... best of luck!

Editor: Wang Tingting

(Note: Latin names should be italicized in the text)

References:

Brown, WD, & Barry, KL (2016). Sexual cannibalism increases male material investment in offspring: quantifying terminal reproductive effort in a praying mantis. Proceedings of the Royal Society B: Biological Sciences, 283(1833), 20160656.

Burke, NW, & Holwell, GI (2021). Male coercion and female injury in a sexually cannibalistic mantis. Biology letters, 17(1), 20200811.

Roeder, KD (1935). An experimental analysis of the sexual behavior of the praying mantis (Mantis religiosa L.). The Biological Bulletin, 69(2), 203-220.

Produced by: Science Popularization China

Author: EVEE (School of Life Sciences, Peking University)

Producer: China Science Expo