Great Black Wasp

Great Black Wasp on Swamp Milkweed

In spite of the “swamp” in its name, Asclepias incarnata can thrive in conventional garden soils. A clumping perennial with rose-colored flowers, it also has tremendous ecological value. Milkweeds are best known as the host plants for the larvae of the monarch butterfly, but they also support many other insects, including the great black wasp (Sphex pensylvanicus). This native wasp is a solitary species that nests in the ground and feeds its larvae live insect prey, especially catydids. The adults primarily eat nectar and prefer species with shallow flowers like milkweeds. These wasps are important pollinators of both common and swamp milkweed, and, like all predators, play a vital role in keeping nearby insect communities in balance.

Location: Urban garden in Cambridge, Massachusetts

Photo ©
Claudia Thompson