Asian Giant Hornets: What You Should Really Know About Them

May 13, 2020

Can you tell which of these insects is an Asian giant hornet? Neither can most people. Experts emplore you, don't kill what you don't know! Top left: Morrison's bumble bee (Bombus morrisoni): native to Utah. Top right: western cicada killer wasp (Sphecius grandis), native to Utah. Bottom left: spider wasp (Pepsis species), native to Utah, Bottom Right: Asian giant hornet (Vespid mandarinia).
Credit Images of Morrison's bumble bee, western cicada killer, and spider wasp by Dr. Joseph Wilson. Image of Asian giant hornet by Wikimedia.

Dr. Joseph Wilson knows a little something about Vespa mandarinia, the species commonly called the Asian giant hornet

“These are social wasps, they have a life-cycle similar to a yellow jacket or a bald-faced hornet," Wilson said. "So the Asian giant hornet is particularly good at raiding honey bee hives because it is big, it’s two inches long, it has really big mandibles. Generally what they’re after is the brood of the honey bee, so the larvae of the honey bee as a protein source.”

Wilson is biology professor at Utah State University at the Tooele campus. 

Despite their dramatic lifestyle, Wilson said the threat to honey bees in the U.S. from Vespa mandarinia has been overblown.

“There’s not any evidence that they Asian giant hornet is established in North America," Wilson said. The records that we have are from last fall in British Columbia, they found a single nest and they destroyed that nest. They found two dead individuals just over the border [with Washington state].  They were within the flight distance of that nest that they destroyed.  So since then there haven’t been any new sightings, and no live sightings have ever been seen in the U.S.”

Since honey bees are not native to North America, colonies here are mostly domestic, and can be easily protected by their keepers.

“One way bee keepers in Japan have done this is they put a wire mesh over the entrance of the hive with holes big enough that the honey be can get through but small enough that the Asian giant hornet can’t," Wilson said.

Wilson said the panic over this insect is causing people to unnecessarily kill beneficial bees and wasps.

“I just don’t want people killing stuff just because they’re scared of a murder hornet that doesn’t live here," He said. "This isn’t the big threat that we should be worried about for bee decline. We already have that with Varroa mite, and pesticide use, and landscape changes, and things like that.”