One of our larger Nebraska insect is emerging and taking flight right now. Cicada killer wasps are impressive looking insects with the females usually routinely measuring 2 inches in length and males hitting the tape measure at 1.5 inches. 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 some spurs.
Female are powerful flyers and catch cicadas on the wing. She will sting the cicada to paralyze it and then take her quarry back to a hole in the ground. Sometimes they will jump from tree branches in the hopes of launching themselves towards their burrow. Most other times though she drags her quarry back to the burrow. 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. Female cicadas do all the hunting and digging, even occasionally working together to construct a burrow. Each tunnel can be 12-15 inches below ground and can up to 36 inches long. 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 in June-July.
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 stinger). In years with high numbers they may also do some damage to 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 and making it less attractive to wasps should be the first thing Nebraskans consider. In terms of insecticides, applications of carbaryl dust (Sevin) or cyflutrhin (Tempo) made directly into the burrow entrances are effective. Broadcast sprays over the area where cicada killers were nesting will likely not be effective in reducing the cicada killer population. Applications should be made at dusk, when the wasps are the least active. It may sound comical, but a tennis or badminton racket is also an effective control tool. Swatting and the wasp with these will physically control them. Just remember to ice down your elbow when you finish, don’t want to get cicada killer elbow!