Harmless in practice. The males that fly at you cannot sting — they have no sting at all. Females can, and are so unbothered by people that stings are rare even among those who dig up their burrows.
Size25–50 mm
MarkingsVery large, 25–50 mm, which is what triggers most reports · Rusty-red thorax with black-and-yellow banding on the abdomen
Adults in high summer, timed to the cicada emergence.
How it behaves
The frightening behaviour and the sting belong to different sexes. Males hold small aerial territories, and will fly straight at a person, a dog or a lawnmower to see it off — with no sting whatsoever. Females ignore people almost completely; they are busy digging burrows, catching cicadas, and hauling them back, often climbing a tree to launch because the cicada is too heavy to lift from the ground.
You’ve found one indoors
Nothing, in most cases. They are solitary, the colony you think you have is many independent females using the same good patch of soil, and the whole thing is over in weeks. If the burrows are somewhere genuinely unworkable, the durable fix is ground cover — they need bare soil, and thick grass makes a site unusable next year.
Common questions
Is this a murder hornet?
No. Northern giant hornets are not established in the United States, and a large wasp digging in a lawn in the eastern US in July is almost always a cicada killer. The colour pattern differs too: this one has a rusty-red thorax.
One keeps flying at me. Will it sting?
It is a male, and it physically cannot. Only females have a sting, and they are the ones ignoring you completely while they work.
Will they damage my lawn?
Barely. Each burrow throws up a small mound of soil and the grass recovers. They are not eating roots and there is no expanding nest.
How do I tell it from a yellowjacket?
Size and behaviour. A cicada killer is two to three times the length of a yellowjacket, is not interested in your food or drink, and nests alone in soil rather than in a paper nest full of sisters.
Tom Norton · CC-BY