Great Black Wasp

Facts, Identification & Control

Appearance

The great black wasp is a very large wasp species, as its name infers. This wasp is black, mono-colored and without colored stripes, spots or other noticeable patterns on the body. Adult females of the species reach about 1-1 ½ inches long and are a little larger than the males.

Behavior, Diet & Habits

The commonly considered distribution of this wasp is the eastern 2/3 of the U.S. Great black wasps are not aggressive due to the fact they do not have a colony to defend and are categorized as solitary wasps. Although their common name sounds intimidating, their name comes from the size of the insect, rather than the aggressiveness of the insect. In fact, male adults do not have the ability to sting and their only purpose in nature is to mate. Females can sting, but only do so if their nest is threatened. Great black wasps are subterranean wasps, meaning they live underground and construct small underground nests where they care for their offspring.

These insects gather prey, most commonly grasshoppers, locusts, cicadas and other large, “fleshy” insects that they feed to their immature offspring. In areas where this insect lives, they can be seen flying with paralyzed insect prey in their mouth and stuffing the paralyzed insect into the underground nest. With all the hunting they do, it is necessary for the female adults to consume lots of high-energy food. Therefore, their primary food source is nectar from surrounding flowers.

Their preferred habitat is areas where prey is located, like meadows, pastures and residential areas where gardens, landscaping plants and flowers are found.

Nest

Great black wasp females build underground nests where she cares for and nourishes her offspring with insects that she captures and brings back to the nest. In areas where the great black wasp lives, they can be seen flying with a paralyzed prey insect in their mouth and then placing the prey in the below-ground nest.

Typically, the nest is constructed in soft, well-drained soil. The female wasp uses her mouthparts and legs to remove soil from the nest site and relocate the excavated soil to the ground surface. The nest is made up of long egg chambers that the female wasp makes from 2-6 paralyzed prey for the larvae feed on. When an egg chamber is ready, the female will lay an egg on the prey and close the chamber. When all egg chambers are sufficiently provisioned, she will close the entire tunnel complex by using her head to tamp down and compact the soil around the tunnel entrance.

Stings

Since great black wasps are solitary wasps, they do not have a large colony to defend as do the social wasps. Therefore, they are not aggressive and only the female adult can sting. Even though they can sting, they do so only if provoked and they sense their nest is being threatened.

More Information

Since the great black wasp is not aggressive and is an important predator of harmful insects and a good pollinator of flowering plants, there is no reason for the homeowner to control them. However, if their presence alarms you, slowly and carefully move away from the wasp and contact your pest management professional for his advice and recommendations. The great black wasp is also known as the Katydid Hunter and Steel-blue Cricket Hunter.