■ Cicada killers are some of the largest insects that live in Nebraska, female wasps are typically 2 inches long. Males are 1.5 inches.
■ Female cicada killers are equipped with a stinger that they use to inject venom into a cicada they catch and then lay their eggs on top of. They also have spurs on their back legs to help them dig tunnels, where they bury the cicadas.
■ Male cicada killers do not have a stinger, instead they have a non-functioning pseudostinger. They will watch areas of female activity though and may fly towards people to inspect them
■ In the short term, insecticidal dusts like carbaryl may drive off cicada killers but renovations to the landscape are the long term solution that must be considered.
Cicada killer wasps are large insects, females are typically 2 inches in length and males 1.5. Both sexes are dark orange in color on the head and thorax and transition into black on the abdomen. There are three prominent light yellow stripes on the abdomen as well. Their legs and wings usually have an orange tinge to them. If you look closely at the last pair of legs on a female wasp you will also notice long spur like organs that they dig with.
In late June and early July, male wasps emerge and wait for females to arrive. Mating occurs and then females prep their nests. Females dig tunnels 12-15 inches below ground in loose, dry soil and make them 36 inches long. Females are also powerful flyers and catch cicadas on the wing. They sting cicadas to paralyze them and then take the cicada back to their tunnel. Once the cicadas are in the hole the female lays an egg that feed on the paralyzed cicadas. Male eggs get one cicada and female eggs get two to three. Much like a mason bee, the female will construct multiple cells in each burrow. Once the nest is full the female will seal the entrances and the eggs will hatch. Larvae develop over two weeks and they spend the winter as a larva in a cocoon then pupate in the spring and emerge as adults.
While these insects are not a sting hazard, they do frighten some people. The males in particular can be territorial and fly towards your face (but do not have a true stinger, only bear a pseudostinger). In years with high numbers cicada killers can damage lawns as they dig their tunnels. If control is desired there are very specific methods of achieving it. Renovating the portion of your landscape that is infested by watering it, changing the soil, or fixing cracks in retaining walls can all minimize the attractiveness of your yard. It may sound comical, but a tennis or badminton racket is also an effective control tool through swatting the large wasps. In terms of insecticides, applications of carbaryl dust (Sevin) or cyflutrhin (Tempo) made directly into the burrow entrances can be effective. Broadcast sprays of liquid insecticides over the area where cicada killers are nesting are not likely to reduce their population. Applications should be made at dusk, when the wasps are the least active.