One might think it is the prey that should be praying, because the Mantids' are swift, accurate and deadly. They have specially shaped forelimbs, with spines that lock together into a deadly grip. Very few insects once captured can ever escape. Mantids also have that curious habit of meticulously grooming themselves after the meal, a grotesque image that would inspire any horror film maker. They have been called the Tyrannosaurus rex of the insect world
Mantids are very useful because they are veracious generalist predators. That is, they will attack and kill anything that is small enough for them to catch. Soft bodied insects in particular are at risk - aphids, leafhoppers, caterpillars, bees, bugs, beetles or any other thing that crawls or flies, the Mantid is veracious and undiscriminating. Being generalists, they will even take other useful insects, such as wasps and robber flies. I once saw a mantid consuming a small Brown froglet - it must have weighed at least several times what the Mantid weighed.
Mantids are very useful because they are able to start consuming almost as soon as they hatch - they only have to wait until their outer coat has hardened. Mantid junior looks just like mom and pop, but smaller, and always wingless. Junior Mantid is called a nymph, and will probably start out on small defenceless prey such as aphids, before graduating to small faster insects such as mosquitos, and then to caterpillars and larger, swifter food sources. as the Mantid matures.
Mantids are useful because they can hunt by day and by night.
Mantids are fast. They are able to sit motionless for long periods, or to rock slightly back and forth, emulating a twig blowing in the breeze. When they strike it is sudden and startling. Sometimes they will just grab their prey in their strong, armoured and spiked front legs, and just start chewing away, slowly consuming their live prey.
As a young boy, I watched them for hours in the field or captured them and kept them in a shoebox or aquarium. I observed them catching a wide range of insects for food, or experimented by feeding a range of insects, whatever I could capture, grasshoppers were the standard fare. They rarely refused a soft-bodied live prey, but did not take beetles or cockroaches unless hungry, and ignored anything that was already dead.
Some species of Mantid have wings, others are wingless, or only one sex may have wings.
You could mistake a stick insect for a Mantid - they are usually larger, and often sit very still for long periods. They are apparently vegetarian. A true Mantid never eats its vegetables.
Mantids belong to the Order Montodea, family Mantidae. They are represented by many species in Australia. Most are green, for camouflage, and vary in size from quite small to around 750mm. They lay a frothy egg mass, which slowly hardens, and hatches from fifty to four hundred young. That is if the eggs themselves are not parasitised by wasps, flies and beetles. Inside the egg case, they are capable of over-wintering - protected by an air cushion from the winter chill. If you notice a grey-brown egg mass in a native shrub, it is probably a Mantid Ootheca, or egg case. I love to watch them on a warm morning in September, when they hatch. The young Mantid is itself vulnerable to predation when it is young, from ants, spiders and yes, they can be cannibalistic. Not many insects are strong enough to tackle an adult Mantid, but birds, lizards, small marsupials or the larger frogs may take them, or they can be parasitised by nematodes.
If I see an egg mass that is under threat from ants or wind, I sometimes take it into the shed. I take care to put it in an open paper bag near the louvre windows, so they can find their way out if I miss the hatching. If I see the hatching coming, I take it outside and put it in the shrubbery, close to the garden.
A limitation on Mantid usefulness is that they are solitary, cannibalistic and not very active hunters, - they lay in waiting. Being generaliats they may also remove some beneficial insects. It is good to encourage native species in your area by using organic gardening methods and avoiding pesticides. Provide a shrub and low tree habitat where ever possible to encourage over-wintering.
If we need another horrible image of the Mantid, it would surely have to be the uncertain fate of the male after courtship and mating (actually only some species). If he does not impress her majesty before the act, she may well eat him. If he is not fast off the mark after the act, she probably will. If he does not get the right grip, she can turn around and bite his head off. No matter, the mating act is not controlled by the brain, but by a ganglia, or 'nerve centre'. The ganglia in the thorax control movement of legs and wings. Abdominal ganglia control abdominal movements including those necessary for copulation. Even if she bites his head off, copulation will probably be effectively concluded.