CICADA KILLERS

Sphecius speciosus

By

Louise Weyer

Program Assistant

The cicada killer, often called a hornet, is a large wasp that may be up to two inches long.  The body is black with horizontal yellow markings on the first three abdominal segments and on the sides of the thorax.  Its legs are yellowish and the wings are dusky.  These solitary wasps are found throughout North America.  The adult has a life span of 60 to 75 days.

The cicada killer overwinters as larvae within a cocoon in the ground.  Pupation begins in spring and adults appear in July and August.  The adults feed the nectar of flowers.  After mating, the female begins to burrow a vertical nest six inches deep, another six inches horizontally and one-half inch in diameter with 10 to 20 oval cells perpendicular to the main tunnel.  She dislodges soil by her mouth and uses her legs for kicking out the dirt.  The dirt forms a regular U-shaped mound, six to eight inches in diameter around the nest entrance.

After the nest is constructed, the female searches for cicadas.  She stings the prey to paralyze it, turns it on its back, and drags or glides with it to the burrow.  Each cell is provisioned with cicadas, one prey for males and two for females.  The female lays an egg on the cicada and seals the cell.  The egg hatches within two to three days, and the larvae feeds on the cicada for four to ten days until only the outer shell remains.  The larvae spin a silken case in which they overwinter.  There is only one generation per year.

These solitary wasps are harmless to humans; however, the female can inflict a painful sting if touched, caught in clothing or disturbed by equipment.  Males have an aggressive territorial behavior and are easily disturbed but do not sting.  Cicada killers are considered a nuisance when they dig holes in lawns, flowerbeds, window boxes, planters, berms, and gardens and leave mounds of dirt.  Homeowners become frightened by their large size and annoyed by their flying around in search of cicadas.

Usually it is not necessary to control cicada killers unless their presence near planters, door entrances, etc., is a nuisance. 

Cultural practices can prevent establishment of cicada killer colonies.  Since they dig their burrows in sunny and light textured soil areas with scant vegetation, lawns can be protected by maintaining a healthy turf.

If chemical control is necessary, insecticides labeled for wasp control may be used.  Locate the nests during daylight hours, and treat after dark or before dawn when the female is in the nest.  At close range, adults can be killed with a wasp aerosol as they light on foliage or enter the nest burrow.  Apply insecticides in accordance with the manufacturer’s label, and follow safety precautions.

Reference:  Ohio State University Extension Factsheet, William F. Lyon