Nature's Praying Predator

One fall afternoon, as I trimmed a Japanese barberry bush, my wife noticed a tan, walnut-sized glob on a twig near the center of the bush. A few shriveled leaves were attached to one side.

She thought it was some disease or gall. After closely inspecting it, I thought it might be an insect egg pod.

"Let's not disturb it and see what hatches in the spring," I said.

Winter passed, and the late April sun warmed the brick on our south-facing front porch. One afternoon I arrived home from work while it was still light. Instead of my wife greeting me at the back door with her usual kiss, she said, "Well, Mr. Pod Protector, come take a look at your little bundle of joy."

As I approached the bush, I saw the tan-colored glob. Dangling below it on a tiny thread was a swaying, squirming mass of grayish-green nymphs clinging to the thread and to each other. There was no mistaking the little critters with triangular-shaped heads, thin-segmented abdomens, and raptorial front legs for anything but praying mantises.

The next day the tiny mantises were performing gymnastics on the barberry bush branches and prowling on the ground. Observing this "outpouring" of life perked our interest in the insect and "egged" me on to take a closer look at the life history of the praying mantis.

From Eggs to Nymphs

After mating with a male in late autumn, the female mantis lays eggs in a foamy liquid secreted from her abdominal glands. She places the foam on and around a twig or branch, where it quickly hardens to form a protective shell about the size and color of an English walnut. The egg case, or "ootheca," is hard to locate because of its color and often secluded location. A female mantis can produce one or more egg cases. Last winter, our barberry bush held six oothecae.

The baby mantises, or nymphs, hatch on warm days in April. They may hatch all at once or in batches. Two hundred or more mantis nymphs may emerge from a single egg case. The young nymphs hang by a thread from the ootheca until their skins harden. It takes the entire spring and summer for a nymph to mature into adulthood.

As a mantis nymph matures and grows, it periodically replaces the outer covering of its body through a process called molting. It sheds its outer covering, or exoskeleton, and replaces it with