Praying mantises belong to the insect family of Mantidae ("mantids"). All mantids have enlarged forelegs (“raptorial legs”) adapted for grasping prey and lined with sharp spines for holding what they catch. At rest, mantids assume an upright posture with forearms folded, which makes them look as if they are praying; hence their common name, “praying mantis.”
Praying mantises mate in the fall, and the females lay dozens to hundreds of eggs in a frothy secretion attached to a plant stem that hardens into a Styrofoam-like egg case. It is commonly believed that the female eats the male’s head during the mating process. In fact, this happens most often when mantises are in captivity, much less often in the wild. The eggs overwinter within the egg case and hatch in the spring into small versions of the adult. Young praying mantises get bigger over the summer and eventually develop wings when they reach adulthood early in the fall.
Praying mantises are predaceous; they eat anything they can catch — mostly flies, beetles, crickets, moths, and grasshoppers. They are ambush predators, sitting and waiting or very slowly stalking with the front legs raised up, poised to clamp down on whatever insect moves in front of them (including other mantises). The grasping response of the mantis is incredibly fast. Prey rarely escape and are quickly devoured headfirst.
There are nearly 1500 species of mantids worldwide, but most of them are tropical. Only three species live in the upper Midwest. The smallest is the native Carolina mantid — mottled, dusty brown in color and about two inches long. The other two species – the European mantid and the Chinese mantid – were introduced to North America in the late 1800’s. The European mantis is about three inches long and pale green. The Chinese mantis is about the same size and bright green or light brown.