Anatomy Mantises have large, triangular heads with a beak-like snout and
mandibles. They have two bulbous
compound eyes, three small simple eyes, and a pair of
antennae. The articulation of the neck is also remarkably flexible; some species of mantis can rotate their heads nearly 180°. Mantises also are unique to the
Dictyoptera in that they have tympanate hearing, with two
tympana in an auditory chamber in their metathorax. Most mantises can only hear
ultrasound. Mantises have two spiked, grasping 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 is a set of discoidal spines, usually four in number, but ranging from none 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 used as a walking appendage, made of four or five segments and ending in a two-toed claw with no
arolium. The abdomen of all mantises consists of 10
tergites, with a corresponding set of nine
sternites visible in males and seven visible in females. The abdomen tends to be slimmer in males than females, but ends in a pair of
cerci in both sexes. They locate their prey by sight; their compound eyes contain up to 10,000
ommatidia. A small area at the front called the fovea has greater visual acuity than the rest of the eye, and can produce the high resolution necessary to examine potential prey. The peripheral ommatidia are concerned with perceiving motion; when a moving object is noticed, the head is rapidly rotated to bring the object into the visual field of the fovea. Further motions of the prey are then tracked by movements of the mantis's head so as to keep the image centered on the fovea. The use of stereoscopic vision differs from humans or primates because they specifically utilize this vision for capturing and spotting prey. The eyes are widely spaced and
laterally situated, affording a wide
binocular field of vision and precise stereoscopic vision at close range. The dark spot on each eye that moves as it rotates its head is a
pseudopupil. This occurs because the ommatidia that are viewed "head-on" absorb the
incident light, while those to the side reflect it. As their hunting relies heavily on vision, mantises are primarily
diurnal. Many species, however, fly at night and may then be
attracted to artificial lights. They have good night vision. Male mantises in the family
Liturgusidae are more frequently collected at night, suggesting greater nocturnal activity or attraction to light sources. This pattern likely extends to other mantis families, where males are also more commonly observed during nighttime surveys. Nocturnal flight is especially important to males in locating less-mobile females by detecting their
pheromones. Flying at night exposes mantises to fewer bird predators than diurnal flight would. Many mantises also have an auditory thoracic organ that helps them avoid bats by detecting their
echolocation calls and responding evasively.
Diet and hunting Mantises are generalist
predators of
arthropods. Larger mantises sometimes eat smaller individuals of their own species, as well as small vertebrates such as lizards, frogs, fish, and particularly small birds. Most mantises stalk tempting prey if it strays close enough, and will go farther when they are especially hungry. Once within reach, mantises strike rapidly to grasp the prey with their spiked raptorial forelegs. Some ground and bark species pursue their prey in a more active way. For example, members of a few genera such as the ground mantises
Entella,
Ligaria, and
Ligariella run over dry ground seeking prey, much as
tiger beetles do. The foregut of some species extends the whole length of the insect and can be used to store prey for digestion later. This may be advantageous in an insect that feeds intermittently.
Chinese mantises live longer, grow faster, and produce more young when they are able to eat
pollen. File:Tenodera sinensis 2 Luc Viatour.jpg|
Tenodera sinensis feeding on a
cricket File:Pm eating pm.webm|thumbtime=46|
Tenodera sinensis consuming a smaller immature mantis File:Mantis catches grasshopper.webm|thumbtime=3|A
chinese mantis catches a
differential grasshopper Antipredator adaptations Mantises are preyed on by vertebrates such as frogs, lizards, and birds, and by invertebrates such as spiders,
large species of hornets, and ants. Some hunting wasps, such as some species of
Tachytes, also paralyze some species of mantis to feed their young. Generally, mantises protect themselves by camouflage, most species being cryptically colored to
resemble leaves or other backgrounds, both to avoid predators and to better snare their prey. Those that live on uniformly colored surfaces such as bare earth or tree bark are dorsoventrally flattened so as to eliminate shadows that might reveal their presence. The species from different families called
flower mantises are
aggressive mimics: they resemble flowers convincingly enough to attract prey that come to collect pollen and nectar. Some species in Africa and Australia are able to turn black after a molt towards the end of the dry season; at this time of year, bush fires occur and this coloration enables them to blend in with the fire-ravaged landscape (
fire melanism). Mantises, like
stick insects, show
rocking behavior in which the insect makes rhythmic, repetitive side-to-side movements. Functions proposed for this behavior include the enhancement of
crypsis by means of the resemblance to vegetation moving in the wind. However, the repetitive swaying movements may be most important in allowing the insects to discriminate objects from the background by their relative movement, a visual mechanism typical of animals with simpler sight systems. Rocking movements by these generally sedentary insects may replace flying or running as a source of relative motion of objects in the visual field. As ants may be predators of mantises, genera such as
Loxomantis,
Orthodera, and
Statilia, like many other arthropods, avoid attacking them. A variety of arthropods, including some early-instar mantises, exploit this behavior and mimic
ants to evade their predators. File:Choeradodis stalii MHNT dos.jpg|Leaf
mimicry:
Choeradodis has leaf-like forewings and a widened green
thorax. File:Gottesanbeterin Abwehr.JPG|Adult female
Iris oratoria performs a bluffing
threat display, rearing back with the forelegs and wings spread and mouth opened. File:Gemmatus.jpg|The jeweled flower mantis,
Creobroter gemmatus: the brightly colored wings are opened suddenly in a
deimatic display to startle predators. File:Ant-Mantis.jpg|Some mantis
nymphs mimic ants to
avoid predators. File:Schizocephala bicornis, Grass Mantis, Udaipur.jpg|The grass mantis
Schizocephala bicornis mimics dry grass both to avoid predators and to approach unwitting prey. File:Mantis Hymenopus coronatus 2 Luc Viatour.jpg|
Aggressive mimicry:
Malaysian orchid mantises are camouflaged pink or yellow, matching the coloration of local
orchids.
Reproduction and life history The mating season in temperate climates typically takes place in autumn, To mate following courtship, the male usually leaps onto the female's back, clasping her thorax and wing bases with his forelegs. He then arches his abdomen to deposit and store sperm in a special chamber near the tip of the female's abdomen. The female lays between 10 and 400 eggs, depending on the species. Eggs are typically deposited in a froth mass-produced by
glands in the abdomen. This froth hardens, creating a protective capsule, which together with the egg mass is called an
ootheca. Depending on the species, the ootheca can be attached to a flat surface, wrapped around a plant, or even deposited in the ground. The cryptic
Tarachodes maurus positions herself on bark with her abdomen covering her egg capsule, ambushing passing prey and moving very little until the eggs hatch. In temperate climates, adults do not survive the winter and the eggs undergo a
diapause, hatching in the spring. Around 90% of the predatory species of mantises exhibit sexual cannibalism. Adult males typically outnumber females at first, but their numbers may be fairly equivalent later in the adult stage, In
Tenodera sinensis, 83% of males escape cannibalism after an encounter with a female, but since multiple matings occur, the probability of a male's being eaten increases cumulatively. Under such circumstances, the female has been known to respond with a defensive deimatic display by flashing the colored eyespots on the inside of her front legs. The reason for sexual cannibalism has been debated; experiments show that females on poor diets are likelier to engage in sexual cannibalism than those on good diets. Some hypothesize that submissive males gain a selective advantage by producing offspring; this is supported by a quantifiable increase in the duration of copulation among males which are cannibalized, in some cases doubling both the duration and the chance of fertilization. This is contrasted by a study where males were seen to approach hungry females with more caution, and were shown to remain mounted on hungry females for a longer time, indicating that males that actively avoid cannibalism may mate with multiple females. The same study also found that hungry females generally attracted fewer males than those that were well fed. The act of dismounting after copulation is dangerous for males, for it is the time that females most frequently cannibalize their mates. An increase in mounting duration appears to indicate that males wait for an opportune time to dismount a hungry female, who would be likely to cannibalize her mate. == Relationship with humans ==