CICADA KILLERS VS. EUROPEAN HORNETS – TUESDAY, AUGUST 15, STEVE CLARK – Entomologist Dr. Art Evans and 88.9 WCVE producer Steve Clark discuss the natural history of solitary cicada killers and compare their behavior with that of the social European hornets.
SC: I’m Steve Clark with Dr. Art Evans, entomologist, and this is What’s Bugging You. I used to be visited frequently by cicada killers.
AE: Oh, yeah.
SC: I love ‘em, but I haven’t seen them in several years.
AE: Oh, now is the season. Just the other day I was walking in our neighborhood, and I saw an area that had several dozen of them. I suspect that they were all males. They all looked a little bit on the small side, and occasionally two of them would grapple with one another, and I was hoping that these would be mating pairs, but they always looked about the same size. Generally the females are a wee bit larger, and they didn’t stay coupled very long. But I love cicada killers and talk about an insect that freaks most people out. (laughing) Many people, and rightly so, are scared by wasps. They think they will sting, and that’s not the case with cicada killers. The males are incapable of stinging. Their sole purpose in life is looking for a female, and the females, which are capable of stinging, focus that activity on their prey, cicadas. Both the males and females are nectar feeders, but the females seek out cicadas, sting and paralyze them and then stuff them into a burrow where they lay their egg on them. The grub hatches from the egg and feeds on that paralyzed cicada.
SC: Now I know they’re ground nesters, right?
AE: Yes they are. Typically they like open ground that is sloped, and their tailings, if you will, are very conspicuous. They’re coffee ground sized, very course. Where I see them in our neighborhood, they’re usually right at the edge of the sidewalk, and even though they’re solitary, sometimes females will share the same entrance to a burrow. The other thing I found that was interesting about their biology is like all ants, bees, and wasps, males result from unfertilized eggs and the females result from fertilized eggs. In the case of cicada killers, the female knows exactly when she’s going to fertilize her eggs, because she stuffs that burrow with two cicadas. Females get more food; males only get one cicada.
SC: Are they the first ones to emerge?
AE: The males are typically the first ones to emerge, and I think we’ve talked before on this show about their early emergence, and they’ll sort of perch in prominent places and await for the females to emerge from their burrows so they can pounce on them right away. A lot of people get confused with European hornets.
SC: European hornets.
AE: Yeah, European hornets have a lot more yellow to them, whereas cicada killers have more black and have a very different behavior.
SC: They’re splendidly banded and colored.
AE: Yes they are. I remember once I was in Pocahontas State Park years ago and I heard this cicada just scream, (laughing) and I looked up and I saw this big thing flying toward me and I thought, oh a cicada killer has it. And it slammed down on the ground right in front of me. I started looking at it and realized something’s odd here, because the wasp was tearing big chunks out of the cicada, and that’s when I realized it wasn’t a cicada killer. Cicada killers don’t do that. They sting and paralyze a cicada, stuff it down the burrow. This was a European hornet that had captured a cicada and was ripping chunks off the very live cicada, and it was protesting the whole time. (laughing) And I did manage to get a few pictures of those on slide film. I’ll have to see if I can find one of those, and we’ll put it up on the website.
SC: Dr. Art Evans is the author of Beetles of Eastern North America. You’ll find photos, audio, and a link to Art’s Facebook page at ideastations.org/radio/bugs.
Photo (Top): Female cicada killer, Sphecius speciosus. Note the long, pointed, and mostly black abdomen and inside margin of compound eyes that are not notched. Photo by Matt Bertone, North Carolina State University. Used with permission.
Female worker European hornet, Vespa crabro. Note the shorter, mostly yellow abdomen. The inside margin of the compound eyes are distinctly notched. Photo by Matt Bertone, North Carolina State University. Used with permission.
European hornet attacking an annual cicada Neotibicen species. Note the hornet’s notched eyes. Photo by Arthur V. Evans, ©2000