When we encounter a large insect, most of us react with fear. This reaction of atavistic repulsion, buried in the deepest recesses of our subconscious, prevents us from contemplating the insect's fascinating appearance and yes, even its beauty. This is true for the protagonist of today’s field notes.
Also known as the insecto de Santa Teresa in Spanish, the praying mantis owes these religious overtones to its upright position: holding its front legs together below its head, the insect seems deep in prayer. Although the mantis shares a classification with common cockroaches, the insects differ widely, starting with the unusually large front legs and elongated thorax (neck) of the former.
Mantises prefer the upright position, standing on their hind legs and keeping their forelimbs bent below the head. Precisely this behavioural attribute is what led the naturalist Linnaeus to classify the insect as the mantis religiosa, a scientific name that closely resembles its common one.
A praying mantis perched on wood
The mantis is so well known that no clues are needed to identify this particular insect. As is often the case with insects and arachnids, the female is much larger, often growing to 12 cm in length and tripling the size of the male, which is rarely bigger than 4 cm.
Autumn ushers in the worst moment of the year for the poor male praying mantises: the mating and breeding season. Well aware of their cruel fate, the males nevertheless respond to the seductive dance of the female. After mounting her and completing the mating ritual, he will be eaten.
Once copulation is over, the female mantis is seized by sudden violent voraciousness. At least twice the size of her mate, she now uses her long forelimbs to get him off her back and up to her mouth. Then she bites off his head and proceeds to eat him.
Before we begin judging this particular trait of the mantis' animal behaviour – an act that appears (and is) macabre and cruel – we have to examine its evolutionary logic. It then becomes clear that this behaviour follows criteria which are essential to the survival of the species.
The female devours the male for the good of the family. By providing his mate with an instant meal, the unfortunate father tends to the mother's urgent need for proteins, which she must absorb to ensure the swift development of their offspring.
But as indicated at the top of these field notes, the mantis is about more than its startling mating behaviour and the atavistic repulsion it inspires in us. What we need to understand is the fundamental role mantises play in the ecosystem as predators of other insect species like cockroaches, beetles, wasps, and spiders which can become problematic if there is an infestation.
This explains why the praying mantis is a protected species in many places around the world, and we need to learn to respect this valuable insect. Plus, the mantis isn't poisonous, it doesn't bite or attack people, nor does it transmit diseases to humans. We won't deny that its presence can be intimidating, but the mantis isn't a dangerous “bug” that needs to be crushed with a shoe or eliminated with a volley of insecticide. The mantis is a spectacular, harmless creature, and we should let it go about its business in peace.
A praying mantis on a human hand
In terms of its biology and behaviour, the mantis lives in areas of abundant vegetation with a temperate climate where it feeds on a variety of invertebrates: no eight or six-legged prey (arachnids or insects) can escape its voracious appetite. Even the sturdy chitinous carapace of the spectacular stag beetle – the subject of a previous field note on this blog – cannot withstand the sharp powerful mandibles of the mantis.