As we head into the latter end of summer, the trees are alive with the sound of insect music thanks to annual cicadas. Depending on your opinion of their singing talents, you might be delighted or horrified to learn of the cicada killer wasp. This parasitoid wasp is one of the largest wasp species in Kentucky. They have to be big because they hunt those large cicadas, sting, and paralyze them, and then drag their body to a hole in the ground where the wasp will lay her eggs on the cicada. After the eggs hatch, the immature wasps will slowly devour the cicada alive. It's a bug eat bug world out there!
Cicada Killer Basics
Adult cicada killer females are up to 2 inches in length, while males are a little smaller, usually around 1.5 inches long. Both sexes have orange-colored heads and thoraxes with black abdomens that have yellow designs on them. The females have spurs on their back legs, which will help them with digging tunnels used as a nest for their larvae. Females also have a stinger at the tip of their abdomen, while males have a pseudostinger (it isn't hooked to a venom sac).
These are not social wasps; they don't have a colony with a queen and workers like yellowjackets or European hornets. Solitary females construct their burrow in the soil and hunt for cicadas. Males can be found hovering near areas of female activity. Females tend to disregard people, but males may attempt to deter humans from approaching burrow areas by hovering near your face. As mentioned before though, they don't have a true stinger, so they are all bark and no bite.
Cicada killer burrows can be quite long underground. An individual female may excavate about 100 cubic inches of soil to make a home for her young. When they sting a cicada, they either fly it back to the nest, drag it, or do a series of aimed "jumps" where they carry it to a tree or bush and jump/glide to get it home. In the burrow, a chamber with a female egg may get 2 to 3 cicada to eat while male eggs get 1 cicada. The height of cicada killer season is late July and early August.
Confusion Over Identity
Because of their size, there have been many inquiries about cicada killers being the Northern giant hornet (scientific name Vespa mandarina, but most famously known as the "murder hornet" in popular media). There are many differences between the species. For example, whereas cicada killers are solitary wasps, the Northern giant hornet is a social insect. This means they have a much higher propensity to sting. The two species also look different upon closer inspection. The Northern giant hornet's head is much larger and broader than the cicada killer; they also have a yellow-orange coloration for their head and their abdomen is banded black and yellow-orange. The cicada killer is darker overall and has distinct patterns rather than bands on their abdomen.
Cicada Killer Considerations
Cicada killers are not considered a stinging hazard. They can sting and it has happened before, but it is rare. Because they are solitary, they lack the defensive mindset that leads to stinging incidents occurring with bees and hornets. Because of this, it is rare that cicada killer wasps need to be managed.
However, cicada killer populations can build in a local area over time. They like areas with loose, dry, light textured soils in the open sun. UK entomologists routinely receive reports of them digging in between parts of retaining walls and also appearing on open playgrounds. They can be scary for people and annoying as they fly around. Sometimes, simply setting up a sprinkler and regularly running it in the area can make it wet enough that the wasps are discouraged away. Other times, a more physical approach to removal can involved using a tennis racket to kill them. It sounds like a joke but is a very effective method of control! Just don't get tennis elbow. For an insecticide-based approach, applying a dust insecticide into the entrance of the burrow will work to kill populations coming in and out of the hole.
Categories: Kentucky, General