Christine Talbot, age 9, of Portland, Maine, for her question:
How long before a praying mantis reaches full size?
The large, green praying mantis spends a lot of time quietly waiting among the leaves. With her head bowed and her hands folded neatly under her chin, she seems to be kneeling in prayer. You might think this is why people welcome her in the garden. But, of course, insects don't say their prayers. The praying mantis is welcome because she devours hordes of other insects that feed on our favorite plants.
Her long green body may be five and a half inches long, and she can spread her wings as wide as a big dragonfly. The praying mantis is one of the largest insects known. You might think that it takes her a long time, maybe years, to reach her full size. It does take her longer to grow up than most insects, but her whole life lasts no longer than a year. She spends the winter as an egg and hatches in the early spring. She grows up, step by step, and reaches her full size during the summer season. She then lays her one batch of eggs and dies before the winter arrives.
The mother praying mantis lays a batch of 200, or maybe as many as 400 small eggs. She wraps them inside a ball of brown foamy material as big as a golf ball and fixes it on a brown twig. The foam dries and the eggs inside stay warm and cozy all winter. When the first breath of spring warms the air, the eggs hatch. The babies look like tiny copies of the big mother mantis though they have no wings.
The tiny mantis is, of course, very hungry, and she instinctively begins to search for other insects to eat. She sits quietly on a green leaf with her thick, spiked arms folded under her chin. Her head tips and turns slowly as her round, red eyes watch for passing insects. Maybe a small fly comes too close. In a flash, she grabs him in her waiting arms and chomps him up for dinner.
The baby mantis eats and eats until her skin bursts. But no harm is done because a new, larger skin will grow underneath. This is called molting. In the next few weeks she molts several times, and each time she sheds her old skin, she is one size bigger. After several molts, two small pads of flesh appear where her wings should be. After the last molt, the praying mantis comes forth with four wide wings. The two front wings are stiff and leafy green which she folds neatly over her long body. Under these outer wings, she has a pair of thinner wings, folded like gauzy fans. We see them only when she flies. When the praying mantis reaches full size, she spends the rest of the summer devouring insects. And in the fall she lays her batch of eggs to hatch next spring.
A lovely butterfly was once a grubby caterpillar and then a sleeping chrysalis. Most insects go through three or four stages of this sort by a process called metamorphosis. But the praying mantis grows up in a different manner. The babies look like their mothers, though they have no wings. They are called nymphs. And nymph insects grow by shedding their tight skins for bigger ones. After the last molt, the nymphs reach their full size and come forth with wings. All this growing up happens in a few summer weeks.