A large solitary wasp, the great golden digger wasp occurs throughout Missouri. It is often seen feeding busily from flowers. The abdomen is orange or rusty-red in front and black at the end. The head and thorax have golden hairs. Like all solitary wasps, this species is not aggressive to humans.
Length: to about 1½ inch (females are larger than males).
Statewide.
Habitat and Conservation
This nonaggressive species is commonly seen visiting flowers for nectar. It prefers fields and other grassy, rather open areas. Nests are dug in sandy soils. These are not social wasps, but nesting aggregations ranging from a few to (rarely) hundreds of females can occur in open sunny sites with the right kind of soil.
Food
Adults feed on flower nectar. They capture and paralyze katydids and crickets, fly or haul them to their burrows, then place them in the nest cells as food for their young.
Life Cycle
This species spends about 1–2 months as an adult before dying. Females excavate long vertical main tunnels in the ground, with nest cells located in short side tunnels. Most nests have 2 or 3 cells, and a female usually digs 5 or 6 nests during her few months of summer activity. Sometimes two females will jointly provision a single nest. The young pass the winter underground in their nest burrows before emerging as adults the following year.
Human Connections
This species does much that endears them to gardeners: They catch grasshoppers, which commonly eat food and ornamental plants; they aerate the soil and improve water’s ability to soak into the ground with their digging; and they pollinate flowers.
They are not aggressive. With their impressive size and busy activity, these wasps are fun to watch. Many famous naturalists have written entertaining, fascinating accounts of this and other digger wasps; those of Howard Ensign Evans (“Wasp Farm”) and J. Henri Fabre are highly recommended.
Ecosystem Connections
Their pollination of flowers helps flowers to reproduce.
Their predation on insects helps control those populations.
They are eaten by many predators, including birds, mammals, reptiles, and more. They even provide a living for the humble parasites that specialize in them.
This wasp, in the genus Sphex, is a member of the family Sphecidae (SFEE-ci-dee), the thread-waisted wasps or digger wasps, which are all solitary. Relatives include mud daubers and the very closely related great black wasp (S. pensylvanicus). Solitary wasps do not have the aggressive defensive behaviors of yellowjackets and other wasps that nest in colonies.
