Last year we had an infestation in the yard of very large, black & yellow wasps, which I understand are cicada killer wasps. How can I get rid of them?
Cicada killer wasp is the largest wasp species in Nebraska. They are up to two inches long and are boldly marked with yellow stripes on a black body. Cicada killers are most abundant during midsummer when their prey, the cicada, is active.
Cicada killer wasps create underground burrows, often around sidewalks, driveways and retaining walls.
The good news is cicada killer wasps don't appear until July, so it's not something you have to worry about right now. They're a very large, black & yellow wasp, that create nests in the soil but they are quite docile. If you leave them alone, they'll Leave you alone. They're beneficial, their larvae feed on cicadas, grasshoppers & cricket, so you shouldn't be concerned. But if you do need to control them, just put some carbaryl (Sevin) dust on the end of a shovel and sprinkle it over the holes.
Cicada Killer Wasp, The Ohio State University Extension
Cicada Killer, Kansas State University Research & Extension