Mantodea - Anatomy and Morphology

Anatomy and Morphology

Mantises have two grasping, spiked forelegs ("raptorial legs") in which prey items are caught and held securely. In most insect legs, including the posterior four legs of a mantis, the coxa and trochanter combine as an inconspicuous base of the leg; in the raptorial legs however, the coxa and trochanter combine to form a segment about as long as the femur, which is a spiky part of the grasping apparatus (see illustration). Located at the base of the femur are a set of discoidal spines, usually four in number, but ranging from zero to as many as five depending on the species. These spines are preceded by a number of tooth-like tubercles, which, along with a similar series of tubercles along the tibia and the apical claw near its tip, give the foreleg of the mantis its grasp on its prey. The foreleg ends in a delicate tarsus made of between four and five segments and ending in a two-toed claw with no arolium and used as a walking appendage.

The mantis thorax consists of a prothorax, a mesothorax, and a metathorax. In all species apart from the genus Mantoida, the prothorax, which bears the head and forelegs, is much longer than the other two thoracic segments. The prothorax is also flexibly articulated, allowing for a wide range of movement of the head and forelimbs while the remainder of the body remains more or less immobile. The articulation of the neck is also remarkably flexible; some species of mantis can rotate the head nearly 180 degrees.

Mantids may have a visual range of up to 20 metres. Their compound eyes may comprise up to 10,000 ommatidia. The eyes are widely spaced and laterally situated, affording a wide binocular field of vision) and, at close range, precise stereoscopic vision. The dark spot on each eye is a pseudopupil. As their hunting relies heavily on vision, mantids are primarily diurnal. Many species will however fly at night, and then may be attracted to artificial lights. Nocturnal flight is especially important to males in search of less-mobile females that they locate by detecting their pheromones. Flying at night exposes mantids to fewer bird predators than diurnal flight would. Many mantises also have an auditory thoracic organ that helps them to avoid bats by detecting their echolocation and responding evasively.

Mantids can be loosely categorized as being macropterous (long-winged), brachypterous (short-winged), micropterous (vestigial-winged), or apterous (wingless). If not wingless, a mantis will have two sets of wings: the outer wings, or tegmina, are usually narrow, opaque, and leathery. They function as camouflage and as a shield for the hind wings. The hind wings are much broader, more delicate, and transparent. They are the main organs of flight, if any. Brachypterous species are at most minimally capable of flight, other species not at all. Even in many macropterous species the female is much heavier than the male, has much shorter wings, and rarely takes flight if she is capable of it at all.

The abdomen of all mantises consist of ten tergites with a corresponding set of nine sternites visible in males and seven visible in females. The slim abdomen of most males allows them to take flight more easily while the thicker abdomen of the females houses the reproductive machinery for generating the ootheca. The abdomen of both sexes ends in a pair of cerci.