We have seen really huge (about 2 inches long) wasps going in and out of several holes in our lawn. They look like queen yellowjackets, but I don’t see any smaller yellowjacket workers along with them. What can we do about them, they’re pretty scary? F.H., Candia, NH

Cicada Killers Are Solitary Wasps

Cicada killer wasp holding paralyzed cicada

A yellowjacket nest will have a larger queen but you won’t see her coming and going from the nest, she’s busy laying eggs. I think you are seeing cicada killer wasps; they are the largest wasps in our area and they don’t have colonies. These wasps have to be big because cicadas are their prey; they need to be powerful enough to paralyze a cicada and drag or fly with it back to their ground nest.

The cicada killer wasp is, as you say, up to 2 inches long with brown, black, and yellow coloration. The female wasp digs burrows in lawns or in bare ground, leaving a pile of dirt around the dime-sized opening. Although these wasps nest singly, several females might dig burrows in the same general area. After the female wasp brings a paralyzed cicada back to the burrow, she stuffs it into the opening, lays an egg on it, then seals the burrow. She then repeats the whole process several times. When the wasp larvae hatch out, they feed underground on their cicada meal for 10-11 months, until they are full grown.

Cicada Killer Wasps Are Not a Threat

Cicada killer wasps are gentle giants. They are extremely docile and nonaggressive. The females have stingers but they only use them if they are physically attacked – in other words, if you sit or step on one. The male wasp guards the nest area while the female does the work. He can be intimidating and noisy, but he can’t sting. He’s all bluff.

In most cases, you don’t need to do anything about cicada killers. They are only around a short time, the nests are completed and sealed in a few weeks. Once the cicadas have died, the wasps are gone because there is no more prey to capture. If the wasps are nesting in an area where children play or if there are just too many and they are doing too much damage to your lawn, an exterminator can treat the nesting site to kill the wasps. Eliminating areas of bare, sandy soil where cicada killers like to nest will help keep them away in the future. Think grass or mulch. In the meantime, try to watch the cicada killers at work, they are truly fascinating.

By Buchanan Bill, U.S. Fish and Wildlife Service [Public domain], via Wikimedia Commons