Praying Mantis have been stalking our gardens and startling our young but are a good sign of a healthy ecosystem. Praying Mantis get their name from a Greek word meaning "prophet," "seer" or "diviner." How they stand when they are in position to catch their prey underwrites their name. Two things contribute to high numbers of praying mantis. They are larger later in the season and therefore more noticeable by an unsuspecting passerby, and warm temperatures cause populations to grow faster.
Two of the most common species are Chinese mantis (Tenodera aridifolia sinensis) and the Carolina mantis (Stagmomantis carolina.) A Chinese mantis is normally tan to pale brown with some green or yellow striping, and it is larger than the Carolina mantis, growing up to 5 inches. A Carolina mantis comes in a variety of colors (green, gray and brown) and patterns; it grows up to 2 ½ inches.
Alien in their façade, all mantises have a fierce pair of grasping legs allowing them to catch their prey, long legs that allow them to lunge and a triangular head that twists 180 degrees around so that they may see all around them. They wait motionless and use camouflage accompanied with a body designed to catch, making them formidable against unsuspecting insects. Some tropical species can mimic a beautiful orchid flower, leaves or twigs. They can change their color to match their surroundings in a period of days.
The most common prey are bees, wasps, flies, scale, mosquitoes, aphids, leafhoppers, grasshoppers, sometimes frogs and an occasional hummingbird. Considering they are nondiscriminatory eaters, they eat bad bugs and good bugs. I have personally seen them eat bees and butterflies. If you spy a preying mantis on your hummingbird feeder, relocate him carefully.
Males tend to be smaller than females. They tend to fly more than their female counterparts, particularly when the females are swelling with eggs. When a female is ready to mate, she emits a hormone. The male cautiously approaches because she may confuse him as prey if she is hungry. Rarely, she will eat his head for nutrition, but copulation persists, transferring his spermatophore. The male is usually allowed the chance to mate again.
After mating, a mass of eggs may be laid on branches or ornamental grasses and quickly hardens for winter slumber. Nymphs will emerge the following spring like an eruption from a foam appendage. They then start their journey to find insects, which may include their brothers and sisters. Most of the mantises that hatch from an egg case will die from starvation or cannibalism; they are territorial and by the end of the summer usually only one adult is left.
Most people are happy to see these ruthless garden warriors and hold off to cut back perennials and grasses until spring when the new crop has hatched.