S phecius speciosus, otherwise known as cicada killers, are 2 1/2 inch long, black-and-yellow burrowing wasps. Despite their formidable appearance, these wasps are basically harmless.
The aggressive males do not have stingers, and the timid females, which fly close to the ground and avoid humans whenever possible, seldom sting, even when provoked. Nonetheless, the burrowing activities of a single female can wreak havoc on a sparse lawn, while the dive-bombing antics of the males can make it uncomfortable to share your yard with them. Getting rid of cicada killers can be a simple process, if they are relatively new to your area.
Step 1: Cicada killers burrow in dry, exposed soils and sands. Growing a lush, healthy lawn is the best defense against them. Before cicada season hits in August, address any bare patches of lawn by seeding or mulching before the wasps have a chance to nest.
Step 2: If cicada killers are present in your yard, follow the low-flying female to her nest. Her burrows are easily identified by the horse shoe mound of dirt surrounding their opening.
Step 3: Once the burrows are located, use a shovel to fill in the holes and hydrate the area heavily with water. It is best to do this during the day while the females are away.
Step 4: Once the burrows have been filled back in and watered down, cover the area with a thick layer of cedar mulch or stone. Cicada killers will seldom burrow into mulched areas and cannot burrow into stone or rock. Keep the area watered for several more days to discourage any further activity.
Step 5: If the burrows are in an area that cannot be covered effectively, sprinkling Sevin Dust around the opening of the hole may help but is typically ineffective, as only one female wasp inhabits each burrow at any given time.
Step 6: The female wasp lays her eggs in each burrow and drags a cicada or two into the burrow for her spawn to feed on over the winter. Filling in the hole will get rid of the current cicada killer, but you will need to watch for early signs of activity the following year to prevent her offspring from nesting in the same general area once they emerge from their winter home.