The Praying Mantid is a beneficial insect sometimes known as the “destroyer of other insects.” Praying mantises eat an array of pest insects—up to 21 different species including aphids, leafhoppers, mosquitoes, beetles, caterpillars, spiders, moths, and grasshoppers.
Mantises do not distinguish between pest insects, neutral insects, and other beneficial insects; mantises are prey insects and will eat just about anything they can capture—including others mantises.
One hundred mantises or about will rid an average garden of most pest insects in short order. Mantises follow the food supply, so once a garden is rid of pests most mantises will move on.
There are as many as 1800 species of Praying Mantid (also called Praying Mantis). They commonly grow from 2½ to 4 inches long, but some Asian species can grow up to 12 inches long.
Here is an overview of the Praying Mantid:
Scientific name: Tenodera aridifolia sinensis
Range: North America, Europe, and Asia
Life cycle: Praying mantises go through three stages of metamorphosis in the course of one year: egg, nymph, and adult. A mantid nymph emerges from its egg case in late spring or early summer; each egg case contains 100 to 400 eggs. The nymph and adult look the same, except the nymph is smaller and has no wings. As a mantid grows it molts or sheds its exoskeleton 5 to 10 times until it is fully grown. The adult will live on through the summer and autumn until it is killed by cold weather; in warm-winter regions mantids may live on in a state called diapause—a biological quite period. Female mantids deposit eggs in autumn then die about three weeks later; the eggs hatch the following spring. Egg cases are hardy and can survive in sub-zero temperatures. Praying mantids thrive in temperate climates that average 70° to 80°F and 60 to 65 percent humidity.
Description of adults: Green or brownish long bodies with papery wings and enlarged front legs adapted for grasping prey; commonly 2½ to 4 inches long.
Nymphs: Nymphs are about ⅛ inch long when they emerge from the egg. They look like small adults except they do not have wings; they feed on aphids, beetles, bugs, leafhoppers, flies, bees and wasps, caterpillars, butterflies, and each other. Nymphs molt or shed their exoskeleton several times before they reach full size.
Eggs: An egg case called an ootheca is a hard foam-like, straw-colored mass or case that contains 100 to 300 eggs. The case can be found attached to twigs or the underside leaves late summer into spring. Wingless hatchlings emerge in spring and begin feed on insects smaller than themselves, usually aphids. As nymphs grow to adults they feed on progressively larger insects.
Feeding habits: Nymphs and adult mantises are ambush predators. They stand perfectly still blending in to their surroundings then catch their prey with their grasping, spiked forelegs. They hold the prey with one leg between the head and thorax, and the other on the abdomen. They eat their prey alive often starting with the head first and then carry on with the body in pieces.
Coverage: One egg case can supply enough mantises for a small garden; three eggs cases provide enough mantises for 5,000 square foot garden. The number of mantises in a garden will decrease as the food supply decreases. Tie egg cases to twigs or branches or place them in a container with holes large enough for nymphs to escape; this will protect egg cases from birds and rodents.
Praying mantid egg cases can be purchased. Keep them refrigerated until you are ready to place them in the garden. Attach the egg cases to twigs or plant stalks or branches until they hatch.