Don’t let their impressive size cause fear of this mild-mannered beneficial insect.
This large wasp is black and dark brown with some narrow bands of yellow or yellow-orange striping on the abdomen. The thorax can be dark brown, while wings are amber. Their bodies are long and thick, and like the European hornet, recognizable for their impressive size. At 1-1.5 inches (26-38mm), they are more than twice the size of a typical yellowjacket. Cicada killers are solitary wasps (there is no colony and no queen), and they nest in the ground. You may see and hear their loud, buzzy flight. Females stay busy digging the nest and provisioning the young inside. The very visible males guard burrows dug by females and chase off other males in the area. Cicada killer wasps become active when you begin to hear cicadas, usually mid-July. They continue their work until September or when you stop hearing cicadas.
Females have stingers used, not just for egg-laying, but for delivering venom that paralyzes cicadas, which are carried back to the nest as a food source for her young.
The occasional sighting is not a concern, and foraging females are not a danger. Stings by cicada killers are rare and likely to occur only if the female wasp is handled, often grabbed or stepped on by accident. Males are intimidating, as they guard nesting females and chase off competitors, but harmless (no stinger!). Look for areas where soil or sand has been excavated. Unless their activity is a direct conflict with your family’s activities, it’s best to ignore cicada killers. They reduce cicada damage in trees.
If you see them foraging, there are likely cicadas in your trees and good nesting sites nearby. Cicada killer females build nests in bare, soft or sandy soil and sometimes in gaps in stone walls. Because of this, they might be found in playgrounds, gardens and golf courses or any place with bare soil. Though solitary nest builders, cicada killers tend to create their own communities because they are apt to find the same areas attractive. Furthermore, females prefer to nest in the same areas they came from the previous season.
As mentioned above, the risk of being stung by a cicada killer wasp is low. Unlike yellowjackets and bald-faced hornets, cicada killer wasps do not defend their nest from disturbance. Therefore, the first question to consider is whether or not you need to take any action. If the nests are located away from where people walk or recreate, they can simply be left alone. If nests are found where people could accidentally step on females or where children may encounter them, control may be needed.
To reduce the numbers of cicada killers, start by considering how the nesting area can be made less attractive to the wasps. Cover bare soil with a thick layer of weed barrier fabric and mulch or stones or let the grass grow long to deter nesting. Cicada killers do not prefer nesting in wet soils, so place a sprinkler in the area for a few hours a day to saturate the soil. A longer-term strategy is to follow recommendations from the Cornell Turfgrass program to grow dense grass or ground covers to deter nesting. As a last resort, call your local cooperative extension office for recommendations of an insecticide sprayed or placed directly in the nest opening.
Always have an action plan in place to care for people and animals who have been stung by any wasp or bee.