The Cicada Killer Wasp (Sphecius speciosus) is a large insect. While their size and buzzing flight can be intimidating, these are solitary wasps that are generally docile toward humans. Conflict arises when their nesting behavior, which involves digging burrows in lawns and gardens, becomes problematic. This article provides safe, effective, and targeted methods for eliminating existing nests and preventing their return through habitat modifications.
Identifying the Cicada Killer and Assessing the Risk
The Eastern Cicada Killer is one of North America’s largest wasps, measuring between 1.5 to 2 inches in length. They have robust, black bodies marked by yellow or orange bands on the abdomen, and their wings are clear with a rusty tint. Females dig nests and are usually seen flying low while searching for a suitable burrowing spot or carrying paralyzed prey.
A key indicator of their presence is the burrow entrance, often a perfect D-shape, surrounded by a fan-shaped mound of excavated soil. The risk of being stung is low because they are solitary and do not defend a colony. Only the female possesses a stinger, which she reserves almost exclusively for paralyzing cicada prey, rarely stinging humans unless physically handled. Male wasps are territorial and will fly at intruders, but they lack a stinger entirely, making their displays harmless.
Targeted Methods for Eradicating Individual Nests
The most effective control method involves applying insecticidal dust directly into the burrow entrance. Dust formulations containing active ingredients like carbaryl or permethrin are effective because they cling to the wasp’s body. The best time to treat the burrows is at dusk or night when the wasps are inactive and resting inside the nest.
To apply the dust, direct the nozzle or duster tip into the opening, injecting a small amount of insecticide a few inches down the tunnel. The wasp will contact the dust when it leaves or enters the burrow. After application, gently seal the entrance with soil to trap the vapors and the contaminated wasp inside.
Secondary methods, such as pouring boiling water down the hole, can be used for single, isolated nests, but this approach is less reliable. Burrows can extend 12 to 15 inches deep, with horizontal tunnels reaching up to 70 inches, making it difficult for water to reach all parts. Treating individual burrows is more targeted and efficient than using broadcast sprays, which are ineffective and can harm beneficial insects. Wear protective equipment, such as long sleeves and gloves, when treating nests.
Strategies for Preventing Future Burrowing
Cicada Killer Wasps prefer to nest in dry, sandy, or sparse soil exposed to full sunlight. Habitat modification is an effective preventative strategy. Increasing the soil’s moisture content during summer is effective, as wasps avoid digging in damp ground. Implementing deep, regular watering makes the lawn less appealing for nesting females.
Improving turf density is another barrier, since thick, healthy grass makes burrowing physically difficult. Mow the lawn at a higher setting, such as three to four inches, which encourages deeper root growth and provides more soil shade. For garden beds or bare patches, applying a two-to-four-inch layer of mulch or installing landscape fabric creates a physical impediment preventing soil access.
After treating active nests, rake away the excavated soil mound and fill the hole to deter new females from using the location in subsequent seasons. If an area experiences recurring infestations, consulting a professional pest control service may be necessary. Specialists can apply preventative granular insecticides to the soil surface that target overwintering larvae, interrupting the life cycle.