Giant Hornets Could Decimate Raspberry Pollinators

by Nate Sanford

illustrator: Hilary Cole

Author’s Note: On December 27, 2020,  funding was finally secured through the “Murder Hornet Eradication Pilot Program,” which was signed into law by as part of the government’s massive 2021 omnibus spending package. The program, introduced by the Secretary of the Interior, will set aside $4 million per year for the next five years. The money will be given to states with active murder hornet problems to help them fund the management, research and public education activities necessary to eradicate the Asian giant hornet and restore damaged bee populations.

Here’s one bit of good news for the winter: murder hornets are taking a break from murdering (at least for now). As days turn colder, the Asian giant hornets that besieged Whatcom County and parts of British Columbia for much of 2020 are either dying off or entering winter hibernation, prompting the Washington State Department of Agriculture (WSDA) to temporarily take down their traps.

But it’s not just giant hornets that are threatening bees; habitat loss, pollution, pesticides and other environmental factors continue to cause alarming declines in bee populations. The city of Bellingham is hoping to help combat this by creating sustainable habitats and pursuing designation as an official Bee City, but the challenge is far from over. And though scientists don’t yet know exactly when, come springtime, the killer hornets will wake back up.The Asian giant hornet (Vespa mandarinia) made headlines when it was spotted in Whatcom County last winter. The hornet is an invasive species that preys on honeybees and other pollinators. The insect’s half-centimeter-long stinger, thumb-sized body, and alarming “murder hornet” nickname drew national attention and cemented the hornets into the cultural ethos of a year that already felt apocalyptic. But, while the hornets can be dangerous to humans, they pose a much bigger threat to local honeybee populations.   

The first female worker hornet specimen in North America was captured by Ruthie Danielsen, a local beekeeper and member of the Mount Baker Beekeeping association. She caught the hornet in a homemade trap about half a mile from her house — and her hives. 

“I was thrilled and then I was horrified,” Danielsen said. 

Danielsen’s beehives have so far been spared from the Asian giant hornet’s wrath, but she’s not taking any chances. While the WSDA has removed most of its traps for the winter, Danielsen is leaving hers up until the weather gets colder and she can be absolutely certain that the hornets are in hibernation. 

Giant Hornets Decapitate Honeybees

Asian giant hornets can be devastating to local honeybee populations. The giant hornets need a massive amount of protein to survive and beehives are their main source of sustenance. When a hornet locates a honeybee hive, they will mark it with a pheromone and bring other hornets from their nest to finish the job. The hornet’s preferred method of attack is decapitation —  just 15 of them can destroy a beehive in a matter of hours.

“There’s absolutely nothing you can do when they’re in the middle of the attack,” Danielsen said. “They will mark that hive and say, ‘it’s mine.’ Once they mark it and they’re actively trying to kill it, it’s their hive now.” 

The wet, temperate climate of the Pacific Northwest is perfect for the Asian giant hornet. A recent study by researchers at Washington State University and the WSDA found that, if the hornets aren’t eradicated soon, they could continue to multiply and spread down the West Coast — decimating local honeybee populations and wreaking havoc on the agricultural economy.

Beekeeping is already difficult, with hives regularly experiencing losses around 40 percent each year. If the Asian giant hornets continue to gain ground in North America, these numbers would likely increase, making it difficult for commercial beekeepers to stay in business. 

“If the commercial beekeepers are having a problem staying in business, who’s going to pollinate all the raspberry fields in Lynden? In the agriculture that we have in Washington state? They all bring hives in by the truckload — are you going to bring your hives to an area that has an active Asian giant hornet count?” Danielsen said. 

Raspberry Crops Need Honeybees

Whatcom County produces 85 percent of the nation’s red raspberries, and is one of the largest berry growing counties in the country. According to the Whatcom Conservation District, there is already a shortage of honeybees in Whatcom County, meaning farmers often need to bring in truckloads of hives to help with pollination each year. If the Asian giant hornet population continues to expand, it could significantly impact agricultural operations not just in Whatcom County, but the entire state.

Since the hornets first appeared in late 2019, the WSDA has been working with local beekeepers and citizen scientists to place thousands of traps and locate nests. 

The above nest was captured in Blaine — it had 776 cells and about 200 queens total.
courtesy photo: Washington State Department of Agriculture

The first Asian giant hornet nest was eradicated in late October 2020. To locate the nest, entomologists from the WSDA trapped a live worker hornet and tied a radio tracking device to it. Once released back into the wild, the hornet led the team directly to its nest, in a wooded area on private property in Blaine, Washington. 

After locating the nest, a team of entomologists donned astronaut-like protective suits and wrapped the tree in cellophane. The team then sucked the hornets out of the tree with a vacuum and pumped the nest full of carbon dioxide to kill any hornets that remained.   

The nest itself was relatively small. Asian giant hornet nests in Asia have been found to contain upwards of 4,000 cells, and are capable of producing 700-800 queens. An analysis by entomologists at Washington State University found that the nest captured in Blaine only had 776 cells and about 200 queens total. 

But, despite its smaller size, the discovery and destruction of the nest was still significant. In a November press conference, Sven-Erik Spichiger, managing entomologist at the WSDA, said that had the nest not been discovered, each of those 200 queens could have gone off and started nests of their own. “It really seems like we got there in the nick of time,” he said.  

Spichiger said that a small number of queens likely escaped before the nest was eradicated, and, if they’ve mated with male hornets, they may go on to start nests of their own. Other hornet specimens discovered near Blaine, Birch Bay and Custer also led the researchers to believe there are other, undiscovered hornet nests still out there. 

Is Genie Out of the Bottle?

Spichiger is cautiously optimistic the hornet threat can still be contained. “If I had told you we have 17 different hits in 17 different counties, I’d tell you the genie is out of the bottle, but right now, it’s just us and British Columbia and it’s a fairly contained event at the moment, so it’s absolutely possible,” he said. 

Because this is the hornets’ first time in North America, there are still a lot of unknowns. Winters in the Pacific Northwest are milder than the winters in Japan and South Korea where the hornets are typically found. Scientists are working to conduct more research, but a lot of the hornet’s behavior is still a mystery. Scientists know the hornets are entering their overwintering phase, but it’s unclear how many will survive, or when they’ll re-emerge.  

“Every time we learn something new, we find out how much more we don’t know,” said Danielsen.  The WSDA is planning to spend the winter improving its trapping techniques and developing its public involvement program.

The WSDA also plans to continue coordinating with authorities in British Columbia, where several Asian giant hornets have also been sighted. People are unlikely to find live hornets flying around during the winter months, but the WSDA is still encouraging citizens to be on the lookout and report any sightings, alive or dead, on the WSDA website.

The Asian giant hornets have captured the public’s attention, but they aren’t the only threat to honeybees. For decades, bee populations across the country have been steadily declining at an alarming rate. U.S. National Agricultural Statistics Service shows a 60 percent reduction in honeybee hives over the past 50 years. The causes are numerous, and experts believe climate change, habitat loss, pesticides, disease and other human factors all play a role. 

Bee City USA

One way to combat this decline is by promoting habitats for pollinators. The city of Bellingham is attempting to do this by pursuing designation as an official “Bee City” through the Bee City USA program. 

The Bee City initiative was introduced by Mayor Seth Fleetwood, who said he has a special connection to bees and other pollinators. As a child, Fleetwood was a self-described lepidopterist, and he still has his butterfly collection from the early 70s. At the start of Fleetwood’s term, he was contacted by an old friend whom he hadn’t seen in almost 40 years. The friend told Fleetwood about Bee City USA, a program that encourages cities across the country to adopt policies that encourage sustainable habitats for bees and other pollinators. 

 “It was just right up my alley, I was really excited to want to promote this sort of thing,” said Fleetwood during a September Bellingham City Council meeting, during which he strongly encouraged council members to support the initiative. 

“The object of it is to create basically a greening of the city and create pollinators and promote private creation of pollinator gardens throughout the city,” said Fleetwood. 

The measure was passed unanimously. According to Clare Fogelsong, Environmental Policy Manager and lead on Bee City efforts, the city is on track to become officially certified within the next few months.

Fogelsong said Bellingham already meets many of the requirements outlined by Bee City USA, but that additional steps are being taken to make the city more habitable for pollinators. The work will include planting more pollinator-friendly plants and implementing policy to improve the city’s pest management methods. The program will also result in the creation of a Bee Committee, made up of city staff and volunteers. The Bee Committee will be tasked with hosting educational events, raising awareness and exploring new strategies to improve bee habitats in Bellingham. 

Along with working on habitat restoration projects, Fogelsong said his office has also been closely monitoring the Asian giant hornet threat. When the hornets were first discovered in Whatcom County, city staff met with the WSDA and distributed hornet traps to public parks in Bellingham. “We were very concerned about it, and I’m pleased that we haven’t trapped any so far in Bellingham,” Fogelsong said. 

Controversial Nickname

The “murder hornet” nickname that some have used to describe the hornets is somewhat controversial. Some scientists, including Spichiger, think the name is too alarmist. The hornets do kill a small number of people in Asia each year, but so do a number of other stinging insects. 

“These are not gonna hunt you down and murder you,” said Spichiger. “If you walk into a nest, your life is probably in danger. I mean that’s the sheer realty, but your life is in danger if you walk into the nest of other stinging insects as well.” 

But some people think the more lurid “murder hornet” nickname is actually helpful. At the start of 2020, the issue wasn’t getting much attention outside of beekeeping circles. It wasn’t until The New York Times published an article with the word “murder hornet” in the headline that public interest skyrocketed. Danielsen doesn’t use the name herself, but she is glad it got people talking. She said that, while trapping and research are helpful, public awareness is the most important factor in combating the threat.

In May, lawmakers in Washington D.C. introduced H.R. 6761, the “Murder Hornet Eradication Act,” which would set aside $4 million a year to help fund eradication efforts. After more than six months, the bill is still in limbo. 

So far, only Democrats have signed on to the bill, something Danielsen said is both surprising and disappointing. Without additional funding, she said it will be difficult to monitor the thousands of traps and conduct the necessary research.

The arrival of the Asian giant hornet has frequently drawn comparisons with the onslaught of Covid-19: a mysterious new threat that originated in Asia arrives in Washington state. It starts to get attention in early 2020, but there are signs that it was here before then. No one knows how it first arrived here, but at this point it doesn’t really matter. The issue is mysterious, and yet to be fully understood. It starts with a few isolated incidents, but quickly grows into a serious threat. And, if more research isn’t done soon, it could spread across the country, spiral out of control and cause irreversible damage.  
“Why is this a goddamn partisan issue?” Danielsen said.

Nate Sanford is a journalism student at Western Washington University. You can follow his work on Twitter @sanford_nate.


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