spider wasp

Photo by James Taulman.

This female black wasp with orange antennae and wings hunts for wolf spiders, which it wrestles with and attempts to sting on the belly in order to immobilize the spider. The reason that the wasp must sting the spider underneath is that the nerve chord in invertebrates runs along the lower (ventral) side of the body, unlike the upper (dorsal) location of the nerve chord of vertebrate animals.

If successful, the wasp then drags the helpless spider to a burrow, where she lays an egg on the still-living spider. The wasp larvae feeds on the spider as it develops and overwinters in the burrow. The new wasp then emerges from the burrow the next summer. Males wasps mate with females and feed the rest of the summer on nectar and pollen. Females are the only ones that hunt for spiders.

Adult female wasps only live a few months during the summer and depend on finding a suitable spider and being able to overcome it in order to successfully produce offspring. I observed the wasp in these photos as it transported the spider about 18 meters to a burrow where the spider was deposited. The wasp probably found the spider in the burrow and chased it to the location where I first spotted the pair, after the wasp had just stung and immobilized the spider. Then it dragged it backwards back to the burrow. The sting of the spider wasp is said to be one of the most intensely painful of any insect or arthropod, compared to an electric shock.

James Taulman is a semi-retired research wildlife biologist, having worked with the U.S. Forest Service research branch and taught zoology, ecology, and other courses in several university positions. He is currently living in the East Mountain region of New Mexico and explores natural areas observing native wildlife and conducting independent research projects.