A Murder Hornet It Isn’t

I recently heard from an agitated homeowner who thought she had seen a “murder hornet” in her yard. Are these insects in Connecticut? She hadn’t and they’re not. Before you reach for a can of insecticide, know that what she saw was an Eastern Cicada Killer (Sphecius speciosus), a type of digger wasp. Although it too has a scary name, this wasp is actually a “gentle giant” and a native Connecticut insect.

The Asian Giant Hornet (Vespa mandarinia), the world’s largest wasp, is native to northern India and eastern Asia. It was discovered on Vancouver Island, Canada, in late 2019, and in Washington State shortly after that, where this year a second nest was recently eradicated. It has been nicknamed the “murder hornet” because it enters hives and decapitates the worker bees. Murder hornets pose a serious threat to the Honey Bee (Apis mellifera). These hornets can destroy a hive in just a few hours.

The United States Department of Agriculture, in cooperation with the Washington State Department of Agriculture, developed an ingenious way to find murder hornet nests. By trapping and hooking up a hornet with a transmitter, the scientists are led to its nest.

The Eastern Cicada Killer uses cicadas as food for its young. After mating, a female digs a tunnel in a loose, sandy patch of soil. Digging begins at the end of July in Connecticut and ends in mid-September. She flies into a tree, finds a cicada, and stings to paralyze it. It’s quite a chore for her to then take the cicada to her burrow, because her prey weighs almost twice as much as she does. She’ll climb up a tree to get some height and fly with the cicada as far as she can, often repeating this to reach her tunnel. There she will lay an egg inside it, and the cicada will become food for her offspring when it hatches. Research has shown that a paralyzed cicada actually lives longer than an unstung one!

Unlike murder hornets, which like Eastern Yellow Jackets (Vespula maculifrons) are social, colonial insects whose workers can sting repeatedly when their colony is threatened, Cicada Killers are solitary nesting wasps that don’t want to sting unless handled or stepped on. Even though solitary, these wasps will sometimes dig holes near one another in loose, dry soil they like. I once found five active tunnels in the sandy soil on the Yale Peabody Museum’s Horse Island in Branford, Connecticut. I was able to walk next to them with the insects flying around me. I wasn’t stung.

Japanese forest researcher Shunichi Makino described being stung by a murder hornet as “being stabbed by a red, hot needle.” For physiological ecologist Joe Coelho of Quincy University the sting of a Cicada Killer is “very mild, like a mere pinprick, and hurts less than the sting of a small sweat bee.”

Eastern Cicada Killer wasps are a part of our local ecosystem and help control cicada populations. Just let them be.