The word mantis comes from the Greek mantikos, for soothsayer or prophet. Indeed, these insects do look spiritual and mysterious, especially when their forelegs are clasped together as if they're in prayer. Take the mystery out of these creatures by learning these 10 fascinating facts about praying mantids.
1. Most praying mantids live in the tropics.
Of approximately 2,000 species of mantids described to date, almost all of them inhabit the tropics. Only 18 native species are known from the entire North American continent. Also, about 80% of all members of the order Mantodea belong to a single family, the Mantidae.
2. In the U.S., the mantids we see most often are exotic species.
For better or worse, the mantids we commonly encounter in many parts of the U.S. are introduced species, not native ones. The Chinese mantis (Tenodera aridifolia) was introduced near Philadelphia, PA about 80 years ago. This large mantid can measure up to 100 mm in length, and is abundant in some northern areas of the U.S. The European mantid, Mantis religiosa is pale green, and about half the size of the Chinese mantid at maturity. This species is well established in most of the eastern U.S., since its introduction near Rochester, NY nearly a century ago.
3. Mantids are unique among insects in their ability to turn their heads a full 180 degrees.
Try to sneak up on a praying mantis, and you may be startled when it looks over its shoulder at you. No other insect can do so. Praying mantids have a flexible joint between the head and prothorax that enables them to swivel their heads. This ability, along with their rather humanoid faces and long, grasping forelegs, endears them to even the most entomophobic people among us.
4. Mantids are closely related to cockroaches and termites.
These three seemingly different insects – mantids, termites, and cockroaches – are believed to descend from a common ancestor. In fact, some entomologists group these insects in a superorder (Dictyoptera), due to their close evolutionary relationships.
5. Praying mantids overwinter as eggs in temperate regions.
The female praying mantis deposits her eggs on a twig or stem in the fall, and then protects them with a Styrofoam-like substance she secretes from her body. This forms a protective egg case, or ootheca, in which her offspring will develop over the winter. Mantid egg cases are easy to spot in the winter, when leaves have fallen from shrubs and trees. But be forewarned! If you bring a mantid ootheca into your warm home in late winter or early spring, you will probably find a few hundred teeny, tiny praying mantids crawling around your house soon after.
6. Female mantids sometimes eat their mates.
Yes, it's true, female praying mantids do cannibalize their sex partners. In some instances, she'll even behead the poor chap before they've consummated their relationship. As it turns out, a male mantid is an even better lover when his brain, which controls inhibition, is detached from his abdominal ganglion, which controls the actual act of copulation. But most instances of sexual suicide in mantids occur in the confines of a laboratory setting. In the wild, scientists believe the male partner gets munched on less than 30% of the time.
7. Mantids use specialized front legs to capture prey.
The praying mantis is so named because when waiting for prey, it holds its front legs in an upright position, as if they are folded in prayer. Don't be fooled by its angelic pose, however, because the mantid is a deadly predator. If a bee or fly happens to land within its reach, the praying mantis will extend its arms with lightning quick speed, and grab the hapless insect. Sharp spines line the mantid's raptorial forelegs, enabling it to grasp the prey tightly as it eats. Some larger mantids catch and eat lizards, frogs, and even birds. Who says bugs are at the bottom of the food chain?!
8. Mantids are relatively young, in terms of evolutionary time.
The earliest fossil mantids date from the Cretaceous Period, and are between 146-66 million years old. These primitive mantid specimens lack certain traits found in the mantids that live today. They don't have the elongate pronotum, or extended neck, of modern-day mantids and they lack spines on their forelegs.
9. Praying mantids do prey on other insects, but are not necessarily beneficial insects.
Praying mantids can and will consume lots of other invertebrates in your garden. It's important to note, however, that mantids don't discriminate between good bugs and bad bugs when looking for meals. A praying mantis is just as likely to eat a native bee that's pollinating your plants as it is to eat a caterpillar pest. Garden supply companies often sell the egg cases of Chinese mantids, touting them as a biological control for your garden, but these predators may do as much harm as good in the end.
10. Mantids have binocular vision, but only one ear.
A praying mantis has two large, compound eyes that work together to help it decipher visual cues. But strangely, the praying mantis has just a single ear, located on the underside of its belly, just forward of its hind legs. This means the mantid cannot discriminate the direction of sound, nor its frequency. What it can do is detect ultrasound, or sound produced by echolocating bats. Studies have shown that praying mantids are quite good at evading bats. A mantis in flight will essentially stop, drop, and roll in midair, dive bombing away from the hungry predator. Not all mantids have an ear, and those that don't are typically flightless, so they don't have to flee flying predators like bats.
- Borror and DeLong's Introduction to the Study of Insects, 7th edition, by Charles A. Triplehorn and Norman F. Johnson
- Insects: Their Natural History and Diversity, by Stephen A. Marshall
- Encyclopedia of Insects, 2nd edition, edited by Vincent H. Resh and Ring T. Carde
- Evolution of the Insects by David Grimaldi and Michael S. Engel
- Preying Mantids: Hiding in Plain Sight, by Roberta Bret, Smithsonian Zoogoer newsletter, Sept-Oct 1997
- Death of an order: a comprehensive molecular phylogenetic study confirms that termites are eusocial cockroaches, by Daegan Inward, George Beccaloni, and Paul Eggleton. Biol. Lett. 22 June 2007 vol. 3 no. 3 331-335