Cicada killers: Large, solitary wasps

By SARA SCUDIER

OSU Extension Master Gardener Volunteer

CANFIELD

We will soon be seeing the most impressive wasp found in Ohio. They are a sight to behold, but not to fear. That is, unless you are an annual cicada.

Eastern cicada killers are large, solitary wasps. The cicada killer is one of the largest wasps in North America. Adults are approximately 1‚Öõto 1 1/2‚Öù inches long, robust, with a black body marked with yellow to white stripes. The head and thorax are dark red, while the wings and legs are brownish. Typically, the male wasps are smaller than the females.

They overwinter as larvae in the soil, and the adults emerge in mid-June to early July. Adults live about 60-75 days and feed on nectar, while the immature stages feed on annual cicadas provided to them by the female wasp.

Males have especially aggressive territorial behavior, but they are incapable of stinging and die soon after mating.

Females feed, mate and dig burrows for several weeks before hunting for cicadas on nearby tree trunks and lower limbs. The wasp stings its prey, turns the victim on its back, straddles it, and drags it or glides with it to the burrow.

Each burrow includes several cells where larvae are raised. Each cell is furnished with at least one cicada (sometimes two or three) and a single egg before being sealed off. Female eggs are provisioned with two or three cicadas while males only get one.

As a result, male cicada killers are much smaller than females. Males establish territories near nesting females and aggressively defend their territory from other intruding males. The eggs hatch in two to three days. Depending on the number of cicadas in its cell, the larva feeds for four to 10 days until only the cicada’s outer shell remains. During the fall, the larva spins a silken case, shrinks and prepares to overwinter. Cicada killers have only a single generation per year.

Like other solitary wasps with no large colony to defend, cicada killers usually ignore people as they go about their business of digging holes and hunting for cicadas. A mound of fine soil surrounds the burrow of each female cicada killer.

Since colonies of burrows are common, infested lawns usually contain several mounds that can smother the grass. Adequate lime and fertilizer applications accompanied by frequent watering to promote a thick growth of turf can usually eliminate a cicada killer infestation in one or two seasons. Cicada killers are generally considered beneficial and control is rarely needed.

To see photos and for information, go to http://go.osu.edu/cicadakillers.