Praying mantids (more commonly known as mantises) have been beloved and feared by different cultures throughout history. They are agile, strong and specially inconspicuous insects: their great ability to mimic different elements that surrounds them and camouflage both in color and shape with the environment make them beautiful and terrifying insects at the same time… for other insects.
Throughout this article, you will learn more about the origin, ecology and also about some interesting curiosities that make this one of the most loved group of insects among entomologists worldwide.
Introduction: Origin
The term “praying mantis” is frequently used to talk about insects that belong to Mantodea order, which has about 2300 described species worldwide nowadays. This name was given them because of the pose their raptorial forelegs adopt when being relaxed: both gathered and close to the body in an angle that resembles arms in a praying pose. On the other hand, the term mantis derives from the ancient Greek term mántis = “prophet or diviner”.
Most people tend to use the term “praying mantis” to talk about any species of mantises, but the truth is that “praying mantis” is the name of a unique species (Mantis is the name of a genus inside the Mantodea order), so the properly common name for these organisms would be “mantids” or just “mantodea”.
The first fossil remains of Mantodea insects date from more than 135Ma (Baissa, Siberia). They would be closely related to termites (Isoptera order) and cockroaches (Blattodea order) according to the great similarities found on their female reproductive systems, and less closely related to grasshoppers and crickets (Orthoptera order). They are usually confused with stick insects (Phasmatodea order) and especially with mantidflies or mantispids (Mantispidae, Neuroptera order), which have raptorial forelegs like mantids.
How do we recognize them?
Despite of the existence of differences between different species, all mantids share the traits that follow:
- Elongated body (10-200mm).
- A pair of claws or raptorial forelegs with one or two rows of spines along the femur and the tibia. The spines point to different directions, so that they fit together when the claws are closed. Thus, the preys that mantids hunt will face lots of difficulties to run away. This process of catching a prey is done at high speeds, so it’s quite impossible to see it at first sight.
- Generally, they have two pair of wings, although some species are wingless or have suffered a reduction of their wings. Most of species of mantids have winged males, while females tend to develop reduced wings or even being wingless. Despite of these differences, it’s hard to differentiate between male and female mantids (we must count the number of body segments).
- Forewings are lightly hardened to protect membranous hindwings which they use to fly. Mantidflies (which we talked about on previous sections) can be distinguished from mantids because they don’t perform a process of hardening of their forewings.
- Mobile and triangular head that stands over an elongated thorax that reminds a neck. This neck allows mantids rotate their head 180º (this is a unique phenomenon among insects), which is essential for them to sense their environment.
- Big complex eyes capable to perceive colors and three ocelli or simple spots in the middle of their head forming a triangle. Ocelli are simple eyes formed by only one lens that are only capable to detect changes in light intensity. They usually appear in groups of three making a triangle in the frontal part of the head of many insects, and almost always located between the complex eyes.
- Filamentous or filiform antennae.
How do they live?
Ecology of the group
Having an elongated body and a pair of raptorial forelegs responds to a predatory style of life: mantids remain immobile and in silence waiting their preys over different vegetable element of their environment (such as leafs, flowers, branches, etc.); it is because of that that some species of mantids have evolved in color and shape to resemble or mimic elements of their environment, which allows them to be unnoticed to preys and potential predators (we’ll talk about this issue in the last sections).
Mantids are generalist carnivorous, so they feed on a great variety of insects that they stalk and hunt at high speeds. Sometimes, it has also been observed a cannibalism behavior among specimens of the same species (or even different species).
In this video, you can watch a mantid hunting a prey. It’s very fast!
Although they can be found around the world, the major proportion of species of this order is located in tropics and in temperate emplacements. They are rarely found in cold environments or in permanent frosted places (they’re absent in Antarctica).
Life cycle
The mating process of these insects is direct, that is, a true copulation where the male has to introduce the sperm directly inside the female body.
All of us have listened about females mantids eating their mates during mating as a type of radical cannibalism. However, entomologists have recently put this into context, so it’s not a phenomenon as usual as we may think: even when it’s a true fact, most of the times this canibalism has been observed in the laboratory and not in the wild. Recent studies consider this phenomenon is a natural response of females that face difficulties that can put in danger their offspring, such as lack of resources or other types of stress sources.
After mating, the female produces a softy ootheca (a capsule with a lot of eggs) with hundreds of eggs. Oothecas have a great water content that avoid eggs being dehydrated, so they are protected from environmental dryness. Later, the ootheca hardens and turns into some kind of shell. A month later, youth mantids (also known as nymphs) hatch and grow until they reach the adult winged phase (hemimetabolous development). If you want to know more about this type of development, take a look at my previous article: “Why do insects metamorphose?”.
Diversity and mimicry
Mantids form a very diverse group of insects. There have been registered about 430 genus and 2300 species more or less in a total of 15 families. Of these 15 families, Mantidae is the one that includes the greatest number of species (inside of which we find the species Mantis religiosa). One of the most representative families of mantids in the Mediterranean region is Empusidae, whose major representative is Empusa pennata (or conehead mantis), an species exclusively located in the western Mediterranean. Empusa pennata has a similar morphology to Mantis religiosa, but they sometimes differ in size.
Almost all mantids, regardless of the family they belong to, show a cryptic coloring body that allow them to being unnoticed by other organisms, both preys and predators.
Some species of mantids resemble a lot to different elements of their environment because they have suffered great modifications along their evolutionary history; thus, they become able to mimic elements of their environment. This is the case of the orchid mantis (Hymenopus coronatus, fam. Hymenopodidade), a species located in rainforests of Malasia, Indonesia and Sumatra whose color and shape reminds of orchids. They always remain over orchids to stalk their preys.
Another stunning case: the ghost mantis (Phyllocrania paradoxa, fam. Hymenopodidae), whose shape reminds of decayed leaves (these mantids tend to stand over dead leaves). Or Deroplatys truncata (fam. Mantidae), which resembles a leaf.
Moreover, a lot of species possess colored expansions or decorative elements they unfold as warning signs or for looking bigger when they face predators or other mantids.
Myths and curiosities
Since ancient times, the mantids have undergone multiple symbolisms. From the literature, history to religion and even martial arts, mantids have had different leading roles.
One of the first historical references of mantis through history is recorded in the ancient Chinese dictionary called Erya (300bC), where mantids are described as symbols of courage and intrepidness. Later, many authors would talk about mantids in their works, both from a scientific point of view, as poetic and philosophic.
On the other hand, religion and mythology would have their contribution too. The Southern African indigenous mythology refers to mantids as deities in Khoi and San traditional myths. In fact, the term to denominate the mantids in Afrikáans is Hottentotsgod, which means “a god of Khoi“. On the other hand, ancient Greeks saw them as diviners or prophets with supernatural powers and also with the ability to show lost travelers the way back home. Even in ancient Egypt there existed a minor deity with mantis shape that assisted in the function of guide the deaths to the other world.
Nowadays, mantids are one of the most commercialized insects as pets. Moreover, due its hunting abilities they have been sometimes used in biological pest control.
REFERENCES
- Amateur Entomologists’ Society – Praying mantids (Order: Mantodea).
- General Entomology (NC State University) – Mantodea.
- National Geographic – Praying mantids.
- Tree of Life Web Project – Mantodea.
- Katherine L. Barry, Gregory I. Holwell, and Marie E. Herberstein (2008). “Female praying mantids use sexual cannibalism as a foraging strategy to increase fecundity”. Behavioral Ecology doi:10.109, Australia.
- Commonwealth Scientific and Industrial Research Organisation (CSIRO) – Mantodea: Praying Mantids.
Main picture from veoverde.com.
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