Nature Smart by Stan Tekiela

Cicada Killer taken in southern MN

I received a text the other day from my neighbor about a killer in our neighborhood. Immediately I was on alert and wanted to know more. After all, it’s not every day that a killer is reported in your neighborhood. The next text I got had a picture of the killer. This confirmed the killer’s identity. As I looked at the picture I thought, yep, we have a killer in the neighborhood, I better get over there right away. Of course, I’m talking about a Cicada Killer Wasp (Sphecius speciosus).

More accurately this wasp is called the Eastern Cicada Killer, because it occurs in the eastern half of the country and up into the upper Midwest. It also ranges as far south as Mexico and Central America. But most people, myself included, just call it “Cicada Killer”.

The Cicada Killer is a very large solitary wasp, ranging in size from one to two inches long. They have four large brown or golden wings, and a black abdomen (hind part) that has irregular shaped yellow stripes. Some say that it looks similar to a yellow-jacket or hornet but those are a very different kinds of insect. The Cicada Killer is a ground dwelling wasp.

Females are larger than the males. They are big enough that when you see one for the first time, they will definitely catch your attention. The Cicada Killer is one of the largest wasps in the United States.

Now for the interesting part. Females digging underground chambers in well drained or sandy soils where she lays her eggs after mating. In fact, this is the easiest way to find evidence of a Cicada Killer is to look for small piles of dirt that she has excavated. Often these nests are under large rocks or under asphalt driveways. They use the rock or driveway as a heat sink, to help rise the temperature of the egg chamber and incubate the egg. Often the nests are on south-facing hillsides or any place where the sun is shining to warm up the land.

So, at this point in the article, you are probably asking yourself several questions. Are these wasps dangerous and why are they called killers. The Cicada Killer can deliver a nasty sting, but they are not an aggressive wasp and will only sting if handled roughly or stepped on. They save their stinging for something much more diabolical.

Females hunt for Cicada’s, the large and noisy insects of summer, but she doesn’t eat them. She stings them with a paralyzing toxin. After paralyzed and helpless, she flips the Cicada over and carries it upside down back towards her nest. The problem is, the Cicada usually weights more than the wasp so she must get up high in a tree so she can “glide” down towards her nest. She deposits the helpless Cicada into her underground chamber. She will lay a single “male” egg on the Cicada before sealing the entrance to the chamber. She will have upwards of ten chambers per nest. When she lays a “female” egg, she will leave two or three paralyzed Cicada in the chamber. When the egg hatches the larval wasp (looks like a maggot) will have a fresh meal waiting for them. It is widely believed that the reason the females are larger is because they have more to eat in the larval stage. After eating, the larva changes into a pupa then metamorphose into the adult wasp and they leave the nest chamber.

As adult wasps they are not dangerous for people. They feed on flower nectar only and rarely sing humans. The adult males hang around the nesting sites looking for females to breed with. If you watch them, it looks like they are aggressively attacking anything that approaches the nesting chambers. In fact, they are just going out to investigate if what they are seeing is a female they can mate with. When they discover it is just a dragonfly or a honeybee, they return to their favorite perch and keep a watchful eye open for a female. If another male Cicada Killer approaches, they often fight but grabbing each other in mid-air and try to drive the other off. When this happens their flight pattern is erratic and they often bump into things. Eventually one lets go and is driven off. The male returns to his perch.

More than likely you have a killer in your neighborhood also. But don’t panic, they are harmless and cool critters that are fun to watch. Until next time…

Stan Tekiela is an author / naturalist and wildlife photographer who travels the world to capture images of wildlife. He can be followed at www.facebook.com and twitter.com. He can be contacted via his web page at www.naturesmart.com.