It is a common belief that male praying mantises face an unenviable fate after copulating with an individual of the opposite sex. We checked how true this stereotype is.

Dozens of materials on various popular science resources are devoted to the fact that female praying mantises eat their males after (and sometimes even during or before) mating. Even if their authors talk about research into this phenomenon, they are far from not always explain how ubiquitous it is. The stereotype about the “fatal” female praying mantis is also reflected in fiction, and in cinema.

The behavior attributed to praying mantises is an example of the so-called sexual cannibalism. This term describes situations where a female eats a male at one or another stage of mating or even courtship. This phenomenon is observed in the behavior of some arachnids and insects, and in rare cases takes place and the reverse process, when males eat females. In most cases, this seemingly contrary action to evolutionary ideas is explained by the need for food. Another version says: in this way, females simply rid the population of weak males. There is no consensus in the scientific community yet.

However, research by biologists shows that the fate of male praying mantises is not at all predetermined. As scientists have calculated, depending on the type of female praying mantis practice sexual cannibalism in 13–28% of cases. At the same time, as some experts emphasize, males may well fertilize several females during their lives, but for this they must be attractive to them from an evolutionary point of view.

In 1994, a group of researchers from the University of Leeds spent an experiment on sexual cannibalism in praying mantises. It turned out that a male’s chances of survival increase sharply if he chooses for mating an individual of the opposite sex that has already eaten. The scientists report: “Not a single well-fed female ate her mate, regardless of the intensity of male courtship. <…> In all cases, except one, hungry females ate their partners, also regardless of the intensity of courtship.”

Thus, not in all cases, male praying mantises pay with their heads for copulation with a female. In any case, this occurs less frequently than in some arachnid species. Whether the outcome of a praying mantis mating will be fatal may depend on many factors. The nature of this behavior is still not fully understood and is a subject of scientific interest for biologists.