MADISON, WISCONSIN (SPECTRUM NEWS) — Reports of the sighting of an invasive, massive hornet in North America reached seemingly every social media feed this week. The Asian Giant Hornet grabbed people's attention with a catchy nickname: The Murder Hornet.
P.J. Liesch, University of Wisconsin - Extension Entomologist and director of the UW-Madison Insect Diagnostics Lab doesn't think calling it the “Murder Hornet” is fair.
Liesch saw reports of the insect killing people with a sting that can penetrate some clothing and looked into death rates in the hornet's native region — Eastern and Southern Asia. He pulled Japanese death data and looked at mortalities associated with stings.
“The overall number of mortalities caused by this insect is actually going to be pretty low, it may be a dozen or fewer per year, so the notion of them being called murder hornets seems to really be kind of blown out of proportion,” Liesch said.
The Asian Giant Hornet can be about one and a half inches long — queens can be two inches long. The hornets are known for feasting on bees, cutting off their heads before eating them.
In it's native region bees have evolved to have natural defenses against the Asian Giant Hornet. In North America, probably not.
“Under the right conditions they can decimate an entire hive of honeybees in the matter of just a few hours,” Liesch said.
The hornet was spotted in one U.S. State — Washington — and in parts of Canada near Vancouver. However, it hasn't been spotted alive this year. All reports of it are from 2019.
“So there's a chance they may not have made it through the winter, that's a big question mark at this point,” Liesch said.
Currently officials are looking for it in Washington. More than a 1,500 miles away from Wisconsin.
“Right now people in Wisconsin can relax about this, it's not an immediate threat,” said Andrea Diss-Torrance, a plant pest and disease special advisor with the Wisconsin Department of Natural Resources.
Torrance said while the hornets are strong flyers, there is no evidence that they are anywhere close to Wisconsin.
The Wisconsin Department of Agriculture, Trade and Consumer Protection agrees.
“This one just hasn't been confirmed anywhere near Wisconsin right now,” said Leeanne Duwe, a public information officer for DATCP.
Like any new invasive species DATCP is monitoring the situation from afar, watching their state and federal partners' progress and findings. However, that doesn't mean the agency is concerned about it at the moment.
“It's not on our radar right now, but it is something we are working to educate state beekeepers about,” Duwe said.
Communications with beekeepers about the hornet is coming through normal communications the agency would have with them.
Invasive species don't always make this type of public entrance into the country. Oftentimes they fly under the radar until they have established.
“This is a particularly unpleasant introduction and hopefully we'll be able to nip it in the bud and it does give a good warning to us, let's be aware and take precautions,” Diss-Torrance said.
Liesch said a good example of how invasive species are more often discovered would be the Emerald Ash Borer — a species responsible for killing about 800 million trees in Wisconsin: https://spectrumnews1.com/wi/madison/news/2019/10/09/invasive-insect-killing-ash-trees-across-wisconsin
“It may have been here a decade or longer before the scientific community really figured out what was going on,” Liesch said.
With the Asian Giant Hornet, knowing about it early is a good thing, it gives wildlife managers a chance to isolate and eradicate it before it spreads widely. However, it also means we don't know much about its potential impact.
For Wisconsin, it's not clear if it could even survive here. The hornet's climate is usually lowland mountain areas or subtropical climates.
“Will they be able to survive in a place like Wisconsin? We just don't know for sure,” Liesch said.
Like most invasive species, humans likely played a role in getting the Asian Giant Hornet to a new continent. It could have been through something like a shipping container, or even an intentional spread.
“We don't know for sure how this asian giant hornet got here, but humans were almost certainly involved to a certain extent,” Liesch said.
Threats to bees are not a new phenomenon. Things like habitat loss from urban sprawl and pesticides are huge threats to pollinators. So are diseases and bugs — some invasive — that can hurt populations.
“All of our bees are facing tough times, and there's a lot of different things going on,” Liesch said.
Liesch points out that Wisconsin has 400 to 500 species of bees. Many of them are wild, solitary and not based in hives.
DATCP hasn't received any calls of potential sightings of the Asian Giant Hornet. However, they have seen people online talk about potential sightings. The agency thinks those are a native lookalike Wisconsin has.
“It looks very similar to the cicada killer wasp because they're about the same size,” Duwe said.
The cicada killers are pretty harmless to humans, leaving people alone unless extremely provoked.
Duwe said if people think they see an Asian Giant Hornet to report it to DATCP, and not approach it themselves.