While finding wildflowers and discovering new (to me) pollinators to feature in my Pond film, this most elegant looking thread-waisted wasp caught my attention. She was spotted foraging in the Joe-pye.

Ammophila nigicans is one of 69 species of thread-waisted wasps known in North and Central America. She is a large wasp, up to 1.5 inches, and is a velvety gun-metal blue black with a reddish orange band across the abdomen. All thread-waisted wasps feature a very narrow waist, called a petiole, which is actually part of the abdomen. It’s interesting to think about because all bodily functions must go through that very narrow petiole.

Ammophila wasps are also called “sand wasps” which derives from the Greek for “sand lover.” To feed its young, a female first digs a hole in sand or clay. Once the single-cell nest is excavated she sets off to find a large caterpillar. The female paralyzes the caterpillar with her stinger then drags the caterpillar to the excavated hole. She lays an egg in the nest and buries caterpillar and egg together. The developing larvae will have all the food it needs to grow into a robust wasp. The caterpillar overwinters underground, emerging the following year. You can see A. nigircans on the wing in Massachusetts from mid-June through September.

The thread-waisted wasp is a solitary wasp, as opposed to the social family of wasps. Social wasps are what we typically associate with when thinking about wasps. Social wasps include Yellowjackets, Paper Wasps, and  Bald-faced Hornets and they share the characteristic of building papery nests that they will defend very aggressively. Solitary wasps are just that and considered relatively benign. They only sting if you pick one up and handle it or step on one.

A note about Joe-pye –

Joe-pye (Eupatoriums) must have the sweetest nectar. I find so many species of insects attracted to the clusters of of tiny florets. After many wildflowers and garden favorites have finished blooming for the summer, Joe-pye begins its flowering period and often finishes up right around the time New England Asters and Seaside Goldenrod begin blooming. The broad flower heads also act as a refueling station for Monarch Butterflies. We’ll find hummingbirds, native bees, and myriad species of butterflies, including Tiger Swallowtails, drinking nectar from the florets. Additionally, scientists have identified over 32 species of Lepidoptera that use Joe-pye as a host plant for their caterpillars.

Beyond providing nectar and food for wildlife, Joe-pye is essential to protecting water quality at ponds, streams, and wetlands. The plant’s deep roots help to reduce erosion and flooding  by stabilizing the soil. The roots also act as a natural filter by absorbing excess storm water run-off and fertilizers. Although Joe-pye is typically found growing in wetlands, it does well in average garden soil, too.