by Blake Newton, UK Extension Entomologist
In Kentucky, annual cicadas are currently singing. For me, cicada-song is the sound of heat, humidity, and summer and I love it. Annual cicadas also mean the return of one of Kentucky's most amazing insects, the Cicada Killer Wasp. I just saw two of them this week. We are bound to see more of them as July progresses.
With a body length of about 1.5", the cicada killer is one of the largest wasps that live in Kentucky. They are easily confused with one of our other large wasps, the European Hornet. Cicada Killers do not live in colonies, though, like hornets do. Cicada Killers are solitary and they are much less likely to sting humans than a hornet. Generally, colony-dwelling bees and wasps (like honey bees, bumble bees, paper wasps, hornets, and yellow jackets) are much more likely to sting humans than solitary wasps and bees. So if you see these huge cicada killer wasps flying around in your yard, don't worry about them: they will only sting if provoked.
Cicada killer wasps don't actually kill cicadas: their larvae do. A female cicada killer will catch and sting an adult cicada (paralyzing it, but typically not killing it) and return it to her underground burrow. Their, she will lay an egg on the paralyzed cicada. The larva hatches from the egg and then devours the cicada.
I suppose it is ironic, but cicada killer wasps tend to miss-out on the mass periodical cicada emergences that occur in the United States. Periodical cicadas emerge every few years, and they tend to emerge in huge numbers. But they emerge early in the summer, before cicada killer wasps are flying. Because of this, at least in Kentucky, cicada killers specialize on annual cicadas--these are the slightly larger cicada species that emerge every year, typically later in the summer.
Read more about cicada killers and their relatives in our Critter Files section, Narrow-Waisted Solitary Wasps. And: Cicadas.