Mantis is an insect belonging to the order Mantodea. About 2,200 species in 9 families are known at present. They prefer to live in tropical and temperate habitats. Major species have been placed in the family Mantidae. The scientific name Manodea has originated from a Greek word meaning prophet. They are sometimes confused with stick insects. Mantises are also known as praying mantises. They have two gratifying, raptorial legs with which they capture and hold prey firmly. The first thoracic segment or the prothorax is elongated and flexibly articulated with and allows the greater movements of the forelimbs while rest of the body is more or less immobile. The head is also very flexible and can be rotated to 300 degrees allowing better and advanced vision. For hunting the ability of vision is very important so they are on on vision only. Majority of species are diurnal but some also fly at night. They became common during the Tertiary period.
They are predators and are known to prey upon small insects but larger species are known to prey upon lizards, birds, snakes, fishes, rodents whom they prey and capture efficiently. Most species are known to participate in cannibalism. They are ambush predators and are known to wait for the prey and devour it when it comes near. They hold and capture the prey with their firm spike forelegs. Mantises are protected from their enemies by the protective colouration. When threatened they stand straight expand their forelegs and wings giving the appearance of a giant terrific insect. The rapid fanning of the wings gives them a dangerous look and in some species the wings are demarcated by characteristic patterns which give them a well protected look. Some species are known to produce a hissing sound through the air expelled out from the spiracles. Some species while flying at night are also able to detect the echolocation produced by the bats and as the bat approaches near the intensity increases and the mantises stop flying horizontally and start descending from their flight towards the ground in order to protect them. Mantises like stick insects show rocking behavior in which they make rhythmic side-to-sde movements.
They are well camouflaged as many species use their protective colouration in order to conceal themselves in the surrounding vegetation or substrate and remain protected from their foes. Some species of Africa and Australia show fire melanism in which after each moult they acquire a black color resembling with that of fire. They also bear the potential to bite their enemies but lack venom. They are not chemically protected and easily fall in the hands of shrikes, bullfrogs and chameleons. Sexual cannibalism is very common among them and has been observed very frequently in the field. The female starts eating by biting off the head of the male or if mating has begun then the movements of the male become more vagorous while delivering sperms. The studies of Liske and Davis have shown that the males of Chinese mantis indulges the females in a courtship dance in order to distract her mind from feeding him but this has not been found to be true for all species of mantises. Exact reasons for sexual cannibalism are not known till mow. Mating starts in the autumn season. During the act of mating, the male clings over the female and grasps her at the thorax and wing bases.
He then releases the sperms which are stored in a special chamber presented at the tip of the female's abdomen. The female then lays 10-400 eggs depending upon the species. The eggs are actually laid in a frothy mass which is secreted by the abdominal glands and when this frothy mass comes in contact with the air it becomes hardened and takes the form a hard capsule known as ootheca. Depending upon the species the ootheca may be attached either to the plant or the ground. The eggs are also parasitized by the wasps but in some species the mother is known to guard the eggs. Mantises are hemimetabolous insects. Eggs hatch into tiny nymphs that resemble adults but are smaller than adults and lack functional genitalia and wings. The color of the nymphs is also different from that of the adults. The nymphs are voracious feeders and they require continuous supply of either aphids or small insects otherwise they will cannibalize each other. A nymph moult 5-10 times depending upon the species. After the final moulting the insect acquires wings but in some species the females are wingless. The tropical species are known to live for about 10-12 years but the species kept in captivity have been known to live for a period of 14 months. In the colder areas the females are known to die early.
The gardeners encourage mantises to be used as biological control agents against many insect pests so they avoid the use of harmful chemical. In many parts of the globe millions of mantis eggs are sold every year for this purpose. Only one species of mantis which belongs to Spain has entered the category of undermined. About 20 species of mantises are native to United States and one belong to Canada.
Mantis also bears special mention in literature as well as mythology.