Does Mrs. Mantis bite Mr. Mantis’s head off during The Act?

Illustration by Slug Signorino

Cecil replies:

The stories about Mrs. M. are a little exaggerated, but they’re no rumor. And believe me, you ain’t heard the half of it. Not only is Mrs. Mantis notorious for chowing down on her man après romance, sometimes she bites his head off during the act. What’s more, it doesn’t discourage him in the slightest — if anything, it inspires him to greater heights.

In fairness to Mrs. Mantis, she doesn’t always have her mate for lunch. In most of the 1,500 species of mantis, in fact, cannibalism is fairly rare. Past reports of mass slaughter were based on observations in the lab, a stressful environment that apparently brought out the female mantis’s bad side.

But even in the field, male manticide occurs “more often than not” in Mantis religiosa, the one type of praying mantis “from which the whole group gets its bad reputation,” according to one researcher. Here’s the scenario: “The male usually tries to approach the female undetected, to seize her unawares, but often he is seen, and the female then catches and eats him, usually beginning at the head. The loss of his head, however, galvanizes the male into action, and he can successfully complete copulation without it. [The male climbs on the female’s back and assumes the position before his partner starts to dig in.] This behaviour pattern, in which she devours the male, is of obvious advantage to the female, and to the species, because she is able to put to good use an otherwise worthless mass of protein.”

Another writer notes, “If a male praying mantis is decapitated the body will immediately assume the reflex attitudes which are characteristic of copulation.” In other words, we’re talking about a species that has become dependent not just on cannibalism but on S&M to perpetuate itself.

The spectacle of M. religiosa mating is something no human male can contemplate without emotion. On the one hand, you have to admire a lad who can do his connubial duty under what have to be described as trying circumstances. On the other hand — let’s speak frankly here — it’s wounding to have a member of the sex described as a “worthless mass of protein.” One weeps to think what it does to the ego of Mr. Mantis. Not only does the female of the species not value you for your mind; by the time she gets done with you, you don’t even HAVE a mind.

Sexual cannibalism isn’t confined to the mantis. A type of fly known as Serromyia femorata mates by snuggling up to its partner and engaging in what sounds like an exceptionally vigorous french kiss: “At the end of mating,” it says here, “the female sucks out the body content of the male through the mouth.” Believe me, I’ll never complain about a lack of female aggressiveness again.

Female spiders also eat their mates on occasion, although contrary to popular belief the black widow spider (Latrodectus mactans, et al) isn’t conspicuously energetic in this regard. On the other hand, black widows do have a tendency to nibble on their kiddies … but let’s take this up later.

Why do I encourage these people?

Dear Cecil:

Your article on Mr. and Mrs. Mantis caught my eye. I’m interested in the subject of peculiar sexual habits, particularly the deadly ones, found within the animal and insect kingdoms. I enclose an article I thought you might get a chuckle out of.

— Chris S., Santa Monica, California

Cecil replies:

The article, clipped from the Los Angeles Times, discusses the mating habits of the ant:

And you thought YOUR pregnancy was rough.

Cecil Adams

Send questions to Cecil via cecil@straightdope.com.