State scientists heading to South Korea to study trapping methods of Asian giant hornet

Since 2019, Asian giant hornets have attacked honeybees in Washington, threatening everything from local gardens to billions of dollars of bee-pollinated crops.

Scientists said the invasive bug also attacks other insects, and it has researchers worried about the impacts if the Asian giant hornet becomes established in the state.

Spring is the time of year when queen hornets emerge and begin laying eggs to form a colony. However, even if scientists make it through the 2022 spring season without a hornet spotted, the Washington State Department of Agriculture (WSDA) said that won’t be enough to declare victory.

"We still have a chance to eradicate them. But we won’t consider them eradicated until we have at least three years of no sightings and none caught in traps," said Karla Salp, public engagement specialist for the Washington State Department of Agriculture.

WSDA has eradicated four Asian giant hornet nests—one in 2020 and three in 2021. It has been eight months since the invasive bug was detected in the state. It raises questions if all of them were exterminated.

"The chances of us being done with this problem is very slim in reality," said Ted McFall, owner of McFall Beeyard in Custer.

McFall is a third-generation beekeeper in Whatcom County. While he was creating new hives at his apiary ahead of the honey season, he was also preparing for what could be another deadly season for his colonies. In November 2019, the Asian giant hornet decapitated an entire hive of 60,000 bees. 

"It was the most bizarre thing that I’ve ever seen as a beekeeper—to show up to an otherwise healthy colony that should have been thriving and doing very well," said McFall. "Whenever this new thing showed up on our shores, I researched everything that I could possibly learn about them and we’re still learning."

Through his research, McFall said he learned the killer hornets were after one thing.

"Asian giant hornets can smell the larva inside the hive. And so they’ll go inside the hive and kill all the adult bees, and then they’re going to rip out their pupa and bring that pupa back home to their nest because the Asian giant hornet have a lot of larvae they need to feed," said McFall while pointing to larva inside one of his hives.

WSDA said all four of the eradicated nests were related. It left researchers wondering if there are other connected nests out there, or if there are new queens that created new nests. New nests could be disastrous since a single nest can produce over 300 new queens.

"Are we going to find nine nests this season? We don’t know. Are we going to find none? The good news is that after we removed that third nest last season, we didn’t have any additional detections. So, that’s promising in itself. However, you just don’t know because we don’t have great traps for these hornets," said Salp.

Trapping the hornet is one thing-- to build a better trap, state entomologists are traveling to South Korea to learn prevention methods and about the hornets in general.

"Our hornets that were found in Washington were believed to be from [South Korea]. And so, we’ll be working with some researchers there to do some additional research on things like trapping, trying to figure out some traps that work well. We also have colleagues in the U.S. Department of Agriculture that are heading to Japan also working on trapping," said Salp.

WSDA is also working on new technology to better detect and track the Asian giant hornet during flight in areas where they are more prevalent. The state is also accepting applications for new paid positions in Whatcom County for trapping. The job will start this summer and operate through the winter of 2022.  WSDA is also preparing to launch a new volunteer program in June to support sighting and reporting efforts.

So far, most of the trapping has been done by community members, referred to as "citizen scientists" by WSDA. The state said more than half of its confirmed detections were from public reports. That’s thanks in part to so many people setting traps with materials provided by the state. McFall said public participation is crucial, especially for beehives like his at having a chance of survival.

"It’s a lot harder for bees to make a good living nowadays. And so, the reality is that we don’t need an additional problem for the bees, and especially something like the Asian Giant Hornet that shows up and slaughters entire colonies at once. It’s not like it just kills some of them and then the colony recovers. It slaughters all of them," said McFall. "If the community was not involved, this would be a lost cause and we’re just going to have to suffer bee slaughters. So luckily there’s a good chance that we might be able to beat this thing just because so many people are looking for this thing."