Ichneumon, << ihk NOO muhn, >> wasp is an insect that lives as a parasite of other insects or spiders. The larvae (young) of most ichneumon wasps develop inside the immature stages of other insects. Some grow inside the bodies of spiders.
Ichneumon wasps measure about 1/8 inch to 2 inches (0.3 to 5 centimeters) long. In addition, the female has an egg-laying organ called an ovipositor that may be up to about 61/2 inches (16.5 centimeters) long. Three threadlike strands make up the ovipositor tube. These strands slide back and forth to move eggs down the tube. Some species of ichneumon wasps drill into trees with their ovipositors and release their eggs in tunnels inhabited by the larvae of beetles and other wasps.
Ichneumon wasps are important to agriculture because they feed on many insects that destroy plants. There are many thousands of species of true ichneumon wasps and of braconid wasps, a closely related group.
