Great Black Wasp

Sphex pensylvanicus

Great Black Wasp

Sphex pensylvanicus

Harmless

Not dangerous

Effectively harmless to people. It is solitary, has no colony to defend, and stings katydids rather than anything your size. Stings on humans are very rare and require handling one.

Size20–35 mm

MarkingsEntirely satin-black, including the legs, with a blue-violet sheen on the wings · Long-bodied and narrow-waisted, 20–35 mm

WhereGardens, meadows and prairie, on nectar plants. Nests in burrows in bare soil.

SeasonAdults mid to late summer

How to tell it apart

Entirely satin-black, including the legs, with a blue-violet sheen on the wings
Long-bodied and narrow-waisted, 20–35 mm
No yellow or orange anywhere — that rules out most of the wasps people fear
Almost always on flowers, especially mountain mint and goldenrod
Flies purposefully between blooms rather than circling people or food

Where you’ll find it

Across most of the United States except the Pacific Northwest.

Gardens, meadows and prairie, on nectar plants. Nests in burrows in bare soil.

Adults mid to late summer.

How it behaves

Solitary, which changes everything about how it behaves. There is no nest full of sisters to defend, so there is no defensive aggression and nothing to provoke by walking past. The female digs a burrow, hunts katydids and grasshoppers, paralyses them and carries them back to provision a cell for a single egg. Adults are heavy nectar feeders and genuinely useful pollinators, which is why you meet them on flowers.

You’ve found one indoors

Nothing. It is one of the better wasps to have in a garden and it is not interested in you, your food or your house. If one is indoors, it will go to a window; open it.

Common questions

Do great black wasps sting people?

Very rarely, and essentially only if handled. They are solitary and have no colony to defend, which is the reason social wasps sting and this one does not.

Is it a tarantula hawk?

No, though the confusion is reasonable. A tarantula hawk has bright rust-orange wings against a blue-black body. This wasp is black throughout, with only a faint blue sheen on the wings.

It is digging in my lawn. Is that a problem?

No. Each female digs a small burrow for her own offspring; there is no expanding colony and no structural damage. The holes close over within the season.

Commonly confused with

Tarantula Hawk Take care
Cicada Killer Harmless
Mud Dauber Harmless

Keep identifying

Identify another animal from a photo or return to the Ants & wasps guide.

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Where this was checked

iNaturalist — Sphex pensylvanicus checked 2026-07-30

Last reviewed 2026-07-30. We identify, we don’t diagnose — what we can and can’t tell you.