According to Texas A&M University, sand wasps (Sphecius specious)--also known as cicada killers, digger wasps and mud daubers--dig tunnels and make nests about 6 inches deep and 6 inches horizontally in sand or sandy soil. They are most noticeable and active in the middle of the summer when one of their primary food sources, cicadas, have made their appearance. While sand wasps can be beneficial (like by killing cicadas, which harm trees and plants), it might be best to keep them away, especially if someone at home is allergic to wasps or if the wasps are nesting near where children play.
Mulch sandy areas with about 2 to 3 inches of a fine mulch, such as shredded bark or compost. In sandy soils and garden beds, this can keep the wasps from nesting in your landscape in the first place and keep them from returning or escaping from their nests.
Care for your lawn properly to help it grow thick and fill in bare spots to keep the wasps from nesting in your sandy soil conditions. Begin to fertilize your yard with a fertilizer labeled for your grass type and reapply as directed on the label. Fill in bare spots with seeds and keep it well-watered, especially the first year. Also, mow grass at recommended heights, usually between 2 and 3 inches high.
Cover a sandbox in the fall to prevent the queen from discovering it as a nice home to hibernate during the winter. A lid will not be enough unless it is completely flush with the sandbox. You may have to securely staple or tape a sheet of heavy-grade plastic to the top of the sandbox.
Spray sandy areas with a pesticide labeled for wasps in the spring before they emerge from the soil (usually around the last frost of the season) and in early fall when the queen is looking for a place to nest. Avoid spraying areas where children and animals play unless you temporarily section off those areas until the pesticide has thoroughly dried or as indicated on the insecticide’s label, according to Department of the California Environmental Protection Agency.
Control cicadas. Spray plants and trees with a pesticide that is safe for your plants and that kills cicadas. A product with the pesticide carbaryl may work well for your landscape. Usually, you must reapply every five to seven days for good control.