Insects overwinter in a variety of ways. Many overwinter in the pupal stage and emerge as adults the following spring. Others spend the winter as adults, resting in some protected environment until the weather becomes warm enough in the spring to signal them to emerge. Still others overwinter as partly grown immatures, nymphs or larvae, and complete their development to the adult stage the following spring. Finally, there are many species of insects that overwinter in the egg stage. In the case of plant-feeding insects, the eggs are usually laid on or near the host plant, and predatory species deposit their eggs in places where the emerging young will have a good chance of finding prey.
Chinese mantids overwinter in the egg stage, and the eggs are protected in a special structure called an ootheca, which is about ¾ inches long, roughly similar in height and width, and can contain several hundred eggs. Female mantids use special glands to produce the substance that hardens into the styrofoam-like ootheca that surrounds and protects their eggs. This insulative covering provides protection from rain and cold, as well as from predators and parasites.
Chinese mantids are a non-native praying mantis species that entered the U.S. more than a hundred years ago, quite possibly as overwintering oothecae attached to nursery plants that were being imported from the Orient. They are considerably larger than our native mantids, with mature females exceeding four inches in length. These mantids are large enough that they have been observed capturing young hummingbirds, making them one of the relatively few arthropods known to prey on vertebrates. Paradoxically, Chinese mantids, or their egg cases, are often offered for sale to gardeners as “beneficial insects.” The idea being that because they eat other insects, mantids must be beneficial. However, Chinese mantids are much more likely to feed on bees and butterflies than on pest insects and are not really “beneficial.” But they are interesting miniature wildlife, and some people keep them as pets.
Last Issue of the Year: It is time for the Bug’s Eye View Newsletter to go into overwintering. This is the last issue of the year, but Bug’s Eye View will resume next spring.
Blake Layton, Extension Entomology Specialist, Mississippi State University Extension Service. The information given here is for educational purposes only. Always read and follow current label directions. Specific commercial products are mentioned as examples only and reference to specific products or trade names is made with the understanding that no discrimination is intended to other products that may also be suitable and appropriately labeled.
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