One of the largest insects in Iowa is a "digger wasp" called the cicada killer wasp. Cicada killer wasps may be up to 2 inches long. They are black with yellow markings on the thorax and abdomen and they have rusty-orange colored wings.
The cicada killer wasp is a solitary wasp; that is, each female lives independently rather than in colonies, though many may choose to nest in close proximity. Each female produces offspring and does not depend on other members of a colony to share in the raising of young or the maintaining of a nest.
Cicada killer wasps are active in July and August. The female digs one of more tunnels in soft soil (often flower beds or gardens) usually along an edge such as where the driveway or sidewalk meets the flower bed or lawn or where the flower bed meets the turf. These edges are landmarks that help the female find her way back to the burrow. Tunnels are about the size of a quarter and may extend 24 inches or more into the ground. The female flies to nearby trees to capture an annual cicada that she stings to paralyze and then labors to carry back to the burrow. One or two paralyzed cicadas are placed in each cell at the end of the tunnel and a single egg is deposited before the female closes the cell and flies away, never to return. The eggs hatch into legless larvae that feed on the cicadas and develop into wasps that emerge the following summer.
The cicada killer, like other solitary wasps, has the capability to sting, but won't unless handled or threatened. Only female wasps have the ability to sting. Stings inflicted by solitary wasps are usually not severe but reaction varies with each individual.
Wasps are generally beneficial and a nest in an out of the way location where it is not likely to be disturbed should be left alone. On the other hand, nests in high-traffic areas may warrant treatment. You can destroy cicada killers and other digger wasps by applying an insecticide dust (e.g., Sevin or permethrin) into the burrow entrance during the night. Cover the nest opening with a shovelful of soil and reapply in two or three days if necessary.
Cicada Killer Wasp
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