NOVEMBER
1999

 

 

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

 

 

 

 

11-24-99

Tropical Mantids Spend Winter in Egg Mass

Praying mantids are a group of insects that most people recognize. But not everyone calls them mantids. Both the name praying mantid and soothsayer are used in England. These names reflect the way the insect rests or waits for prey. The knees are bent and the front legs appear as if the insect could be holding a prayer book.

In some of the southern parts of the United States, mantids are known as mule killers. This is apparently based on the rather curious superstition that the brownish substance that sometimes comes from the mouth of the mantid will kill mules. 

Mantids are also called “rearhorses” from the rearing posture that is assumed when they are about to grasp another insect. This is when most people see mantids, for like most other predatory insects they seem to always be ready to nab a meal. A mantid's appetite for other insects is what endears it to humans. We just love to watch insects being destroyed.

Mantids are most common in tropical regions of the world. Some are called flower mantids because they resemble the flowers of certain plants. One especially striking flower mantid is a vivid pink color, which matches the color of an orchid where it hunts. Since it blends in so nicely with the flower, the mantid just sits and waits for unsuspecting insects to land. The color also protects the mantid from other predators that might be willing to turn the tables on the mantid and make a meal of it.

A few mantids live outside tropical regions. There are about 20 species of mantids that live in the United States, and most are found in the South. One of these is known as the Carolina mantid. It is one of the smaller mantids and not nearly as large as the European mantid, which also is common in the eastern part of the United States.

The European mantid was most likely introduced into the United States in northern New York. It probably came into this country as egg masses on nursery stock. Another foreign mantid came from Japan and showed up around Philadelphia in 1896. Unlike most other insects that become pests when introduced to our shores, we actually are happy that the mantids are here because of their predatory nature.   

Foreign mantids arrived here in the overwintering, or egg mass stage. Several insects spend the winter in the egg stage but many, like grasshoppers and corn rootworm beetles, are in the soil. The soil, like a blanket, protects them from harsh winter temperatures. 

A few insects tuck their eggs under the bark of trees or drop them in leaf litter. But praying mantids lay their eggs in a frothy mass attached to the stem of a plant. Occasionally, an egg mass will be discovered on the side of a house or on a window pane.

Even though the egg masses might be in plain sight, they often go unnoticed. Mainly because most of us don't recognize mantid egg masses when we see them. These masses are large and may contain up to 400 eggs laid in parallel rows of about 40 per row. The eggs stand on end and are inclined toward the center channel, much like feathers on the shaft of an arrow.

The egg mass is white when it is laid but quickly turns a tannish-brown color. The mass blends in nicely with the bleak colors of winter vegetation and are easily overlooked—unless you know what you are looking for. 

As Pulitzer Prize-winning author Annie Dillard stated in her book “Pilgrim at Tinker Creek”: “I have just learned to see praying mantis egg cases. Suddenly I see them everywhere; a tan oval of light catches my eye, or I notice a blob of thickness on a patch of slender weeds.”

 

Writer: Tom Turpin
Editor: Elaine Lambert