“Holy smokes! What the heck is THAT???!!” It was early August 2007 and I was moving into my current home in Cocoa. The guys from the moving company had spotted an enormous wasp patrolling around in the front yard and were in fear for their lives. Cicada-killer wasps tend to have that effect on people. They are HUGE—the females can be almost 2 inches long—and they do appear to be aggressively looking for some poor victim to sting. And a wasp that big must have one HECK of sting, right?
Well, basically, no. The poor cicada-killer gets a bad rap. Read on to learn more about this fascinating and misunderstood critter.
The eastern cicada-killer (Sphecius speciosus) can be found throughout much of North America, pretty much everywhere east of the Rockies. Females dig their nesting burrows, which may be up to 4 feet long, into sandy soil during summer. The nest will contain several chambers. The female cicada-killer hunts until she finds a cicada, and then stings it. Her venom paralyzes the cicada, which she carries alive back to the nest (no small feat, since the cicada may be three times her own weight) and puts it into one of the nesting chambers. Then she lays an egg on the cicada and seals up the chamber. When the egg hatches, the cicada-killer larva feeds on the paralyzed cicada. It will overwinter as a pupa and then emerge the following summer to start the cycle over again.
Cicada-killers may look ferocious but they’re actually quite harmless. The males don’t possess a stinger, and the purpose of the female’s stinger is to inject paralyzing venom into cicadas, not to be a weapon of defense. It is said that you pretty much have to actually catch one in your hand and squeeze her in order to get stung. Those who know say the venom is quite weak. I can attest to their non-aggressive nature: in 2012 I counted 22 nests in my front yard. I mowed every week, sometimes inadvertently crushing the entrance holes so that the owner of the nest had to rebuild. I never got stung or even chased by the big wasps.
Male cicada-killers are often seen patrolling around and zooming over to investigate anything that enters their vicinity (including humans). While it may appear that they’re looking for victims to attack, what they’re actually on the lookout for is competition for females. They may buzz up and check out an invader who wanders into their territory, but they won’t attack unless the invader is another male cicada-killer. On the other hand, aerial dogfights between two or more males are common and they sometimes slam into trees, buildings and by-passers as they battle one another.
While some people get upset at the prospect of their perfect lawns being defaced by little sand hills that result when cicada killers build their nests, the damage tends to be minor and temporary. Once nesting season is over, rain and lawn irrigation will gradually pound the sand back into the ground. Cicadas, on the other hand, actually do inflict damage on desirable landscape trees and shrubs by laying their eggs under soft new bark. According to NC State Extension Service, 100 female cicada-killers can rid the world of about 16,000 cicadas during a typical nesting season. (Humans haven’t found an effective or efficient way to control cicadas, by the way.)
Interestingly, adult cicada-killers don’t actually feed on cicadas, but on flower nectar. I see this as another reason to plant flowering plants! Big and scary as they are, cicada-killers spend most of their lives in the larval stage, underground, munching on still-living cicadas that were provided by their parents. Once they emerge from the pupal stage, they only live 4-6 weeks. Once they have mated and laid the eggs for the next generation, they die.
So if you see one of these huge wasps cruising around, take a few minutes to stop and watch. Locate the female’s nest and wait patiently. You may be rewarded by seeing her return with a cicada, which she’ll drag down the entrance hole, then emerge and return to the hunt a few moments later. It’s fascinating to watch—who needs tv when you can see things like this in your own backyard!