Ichneumon wasps are perhaps the largest animal family on the planet, made up of between 60,000 and 100,000 different species. Approximately 5,000 to 8,000 can be found in North America, and of these eleven are of the genus shown here (Hymenoptera: Ichneumonidae: Ophion sp.). These are among the most common Ichneumon wasps in North America and they also happen to be attracted to lights. Because of this it’s not unusual to see them from late spring to late summer hovering around porches at night.
Although Ichneumon wasps are a vast and very diverse group of insects, one notable characteristic they all have in common relates to their wing venation. There are technical terms to describe this, but most people just call it the “horse head” shape that appears mid-wing:
Many insects feature one or more simple eyes called “ocelli,” often in conjunction with larger compound eyes. Ophion species have three very prominent ocelli, effectively giving them five notably large eyes. While the compound eyes have enough resolution to make out images, the ocelli only detect light and motion.
Adult Ophion wasps breed during the warmer months of the year. Inseminated females seek out caterpillars and lay an egg on each one they find. Once the egg hatches the wasp larva bores into the caterpillar host and slowly devours it from within, eventually pupating and emerging as an adult. This parasitoid behavior is like parasitic behavior, but it ultimately kills the host. Since the caterpillars of many butterflies and moths are economically damaging pests of crops, many Ichneumon wasps are important biological control agents. Ophion species do not happen to be among of the more useful to humans.