What to Know About the Great Black Digger Wasp in Iowa

You’re out in the yard on a summer afternoon when you spot a large black wasp flying low to the ground. It looks a little intimidating—but is it actually dangerous? If you live in Iowa or other parts of North America, chances are you’ve just seen a Great Black Digger Wasp.

Here’s what you need to know about this wasp, including how it behaves and when to call for help.

Key Takeaways

• Great Black Digger Wasps are large black insects that build underground nests in sunny spots like yards and gardens.
• These wasps rarely sting people but stings can happen and may cause swelling or allergic reactions in some individuals.
• Infestations do not happen but nests can appear near walkways flower beds or areas where kids and pets play.
• Pest control professionals can safely remove nests while protecting pollinators like honey bees nearby.

What is the Great Black Digger Wasp?

The Great Black Digger Wasp is one of the largest wasps in Iowa, growing up to 1.5 inches long. It has a shiny black body, a narrow thorax, and dark wings with a bluish shimmer—no yellow markings like yellowjackets, hornets, or paper wasps.

As a type of digger wasp, it builds underground nests in sunny, sandy spots like gardens, lawns, or even sidewalk cracks. 

Unlike social wasps that form colonies and defend their nests, this species is solitary—each female wasp works alone to raise her young.

Are They Dangerous?

Yes, female wasps do sting—but not people. If you see one flying low over your yard, don’t worry. She’s probably hunting grasshoppers or katydids, not you. After paralyzing her prey, she takes it to her nest, lays a single egg, and her larvae feed on it once it hatches.

Most folks in Iowa will never get stung unless they try to handle one or accidentally step on it barefoot. These wasps are focused on hunting, not bothering people.

Unlike other common types of wasps, they won’t chase you or swarm if you get close. But if you’re allergic to painful stings, it’s still smart to be cautious.

While serious reactions are rare, a study found that wasp stings can cause anything from mild swelling to more serious allergic reactions, depending on the person.

Will They Cause an Infestation?

Because these are solitary wasps, you won’t see a large infestation like you might with yellowjackets or hornets.

Each underground nest is managed by one female Great Black Wasp, and while you might spot a few nests nearby, it’s nothing like the swarms of social wasps. That said, their nests can pop up in unwanted areas—like flower beds, pathways, or close to your home’s eaves.

If you notice multiple nests in a high-traffic area, especially where kids or pets play, you might want to take action.

Should You Remove Them?

In most cases, there’s no need to panic or rush to eliminate Great Black Digger Wasps. But if their presence is causing concern, it might be time to reach out to a pest control expert.

At Miller Pest & Termite, we offer professional services throughout Des Moines and we can help assess whether digger wasps or similar types of wasps like cicada killer wasps or mud daubers are active around your property.

Our pest control exterminators are trained to handle everything from wasp nests to termite problems, and we’re equipped to safely treat your home, garage, or eaves—up to 25 feet high—all while protecting beneficial pollinators like honey bees.

Contact us today and let us handle the problem—whether it’s one wasp or an entire nest.