Wednesday, June 2, 2021

On the lookout for "murder hornets" along state roadways

Update Thursday, June 17: The Washington State Department of Agriculture and the U.S. Department of Agriculture have confirmed the first report of an Asian giant hornet for 2021. A resident in Marysville reported the deceased hornet on June 4.

By RB McKeon

While our maintenance crews are always on the lookout for noxious weeds along our highways, for the past year or so there's been another type of pest that has gotten our attention and probably yours. And while Japanese knotwood and Scotch broom may strike fear into some, it's nothing compared to hearing about the infamous "murder hornets!"

That's right, we're talking about the old Vespa mandarinia, AKA Asian giant hornets or, yes, murder hornets. And our crews have been taking an active role in helping prevent this new pest from spreading.
A close-up look at an Asian giant hornet
Courtesy Karla Salp, Washington State Department of Agriculture

What's a murder hornet?

This invasive species of hornet from Asia was found last year in Whatcom County. While native hornet species are a natural part of the state's eco-system, these non-native hornets can dominate local species and pose a serious threat to Washington honeybees – thus earning the nickname murder hornets. Although these insects are not typically aggressive towards humans, their stings are extremely painful and can leave permanent scars. And if you want to see these murder hornets murdering, you can watch this video shared by our friends over at the Washington State Department of Agriculture.

Why do we care?

As managers of more than 100,000 acres of public land across the state, our agency plays an important role in identifying, managing and mitigating invasive species. Most of the time this work, in partnership with the County Noxious Weed Control Boards and the Washington state departments of Agriculture and Ecology, is focused on combatting a host of noxious weeds found along highways. This work is vital in being stewards of our public lands, including protecting crops that support economic health and preserving native vegetation that is necessary for a healthy eco-system.

Watching for and trapping suspect hornets may not seem like one of our agency's duties, but it's all part of our commitment and responsibility to protect the environment. We live here too, and don't want our crews to be stung by these hornets or see native species harmed in our communities.

"As stewards of state lands, we have a responsibility to minimize any harm that our transportation system has on the environment and the economy," said Ray Willard, our roadside maintenance program manager. "When something like invasive hornets threaten our state, our crews are always willing to go the extra mile, learn new protocols and support our state partners."
Our crews will be putting out and monitoring traps like these in search of Asian giant hornets.
Courtesy Karla Salp, Washington State Department of Agriculture

OK, so what's the plan?

This year, we will again help track these hornets. Beginning in July, our crews will set hornet traps in Northwest Washington along the highway right of way and monitor them throughout the season. This is part of the Department of Agriculture's overall focus on trapping in Whatcom, Skagit, Island, San Juan, Jefferson and Clallam counties. The plan is to have at least 1,200 traps in place across the state between all agencies and citizen scientists, along with working with cross-border agencies in British Columbia to track the hornets.

Traps are relatively simple to make, requiring a plastic bottle and simple ingredients like orange juice, rice wine or brown sugar. Traps are placed at least 6 feet high on trees near forest edges. As our crews are out doing regular maintenance, preservation and construction work they are able to check traps weekly for any captures and turn anything of note over to the Department of Agriculture for further analysis. If you are interested in participating in trapping as a citizen scientist, WSDA has details on its website.
This Asian giant hornet was found with a nest during a 2020 tree removal.
Courtesy Karla Salp, Washington State Department of Agriculture

How can I tell if it's a murder hornet?

But how do our maintenance crews (or you) know what to look for? What's the difference between a murder hornet and any old regular hornet? The Department of Agriculture created a short training video for workers, highlighting the risks these hornets pose and what to do if we come across them. Asian giant hornets are:
  • Usually 1½ -2 inches in length
  • Have a large orange head with prominent eyes
  • Have a black and orange/yellow striped abdomen
  • From large colonies that usually nests in the ground
If you see a suspect hornet

If you see or think you've seen one of these hornets, please report it online at or via email If it's safe to do so, photograph it and send the photo to the contact above and put the specimen in a jar or baggie in the freezer until you hear back. These hornets are not typically aggressive toward humans, but they will still sting people who attempt to handle them. They will also sting while defending their nest or defending a beehive they are attacking. Please don't swat at or otherwise disturb the hornets and just focus on reporting the sighting or specimen. The Washington State Department of Health has information about what to do if you are stung.