Asian Giant Hornet (Washington State Department of Agriculture photo)

Asian Giant Hornet (Washington State Department of Agriculture photo)

Local beekeepers face another threat

  • Thu May 14th, 2020 1:30am
  • News

To the dismay of local beekeepers, the Asian Giant Hornet has been seen in the region. Growing to three to four times larger than a yellowjacket, the Asian Giant Hornet, or Vespa mandarinia, is the largest hornet in the world and carries a potentially lethal sting.

These enormous hornets have a reputation for decapitating honeybees — which is likely how they acquired the popular nickname “Murder Hornet.” While that isn’t good news, they are not aggressive toward humans, according to experts.

“It is not a ‘Murder Hornet,’” said Washington State Department of Agriculture entomologist Chris Looney, who has Ph.D. in environmental science. “It’s just a regular old invasive bee-eating hornet from Asia.”

The Asian Giant Hornet has been spotted on both Vancouver Island, Canada, and in Blaine, Washington. A nest was found on Vancouver Island and two hornets, whose DNA did not match those of the Canadian-found ones, were found in Blaine.

One of the two hornets discovered in Blaine was analyzed by a scientist in Japan who determined it came to the United States from South Korea, according to the State Environmental Policy Act report.

To make matters worse, Looney added, the Pacific Northwest is similar in climate to the giant insect’s native habitat of Japan and the temperate regions of Asia, making Western Washington an ideal home.

“I fear the islands could be really in the crosshairs of an expanding population,” Looney said.

Orcas had a scare earlier this year with one potential sighting, however, it turned out to be a false alarm, and was a native hornet, according to San Juan County’s Washington State University Extension Director and Regional Agriculture Specialist Brook Brouwer, who has a Ph.D. in crop and soil sciences.

Giant Asian Hornets are typically only aggressive toward people if they feel threatened, their stingers are long enough to penetrate bee attire, and the venom is more toxic than the native bee, hornet and wasp species, Brouwer said. Between 30-50 people die annually in Japan from Giant Hornet stings, according to the United State Department of Agriculture — either from receiving a multitude of stings, or having an allergic reaction.

In comparison, an average of 62 people die each year from hornet, wasp or bee stings in the United States, according to the Centers for Disease Control and Prevention.

There are several theories regarding the hornet’s recent arrival, according to Brouwer. Researchers believe they were either introduced on accident — by hitching a ride in a cargo ship from Asia to a West Coast port or in someone’s belongings — or on purpose. A number of travel magazines and food blogs demonstrate a variety of ways to eat the protein-packed insect.

According to the WSDA, the hornets grow between 1.5 to 2 inches long and have large cartoonishly prominent eyes on their orange-yellow head. The abdomen is striped black and yellow, similar to a yellowjacket.

The insects form large colonies and usually nest in the ground.

“Asian giant hornet attacks and destroys honeybee hives. A few hornets can destroy a hive in a matter of hours,” the WSDA website said. “The hornets enter a ‘slaughter phase’ where they kill bees by decapitating them. They then defend the hive as their own, taking the brood to feed their own young. They also attack other insects but are not known to destroy entire populations of those insects.”

The slaughter phase, the website explained, typically occurs late summer or early fall. Brouwer added that from March through April queens begin to emerge from hibernation, so the time to eradicate the hornets is now.

Looney said he is concerned about the hornet’s arrival.

“Anytime a species shows up in a new ecosystem the potential for deleterious effects is high, even if we can’t perfectly predict those effects,” Looney said, explaining that the hornets are an adaptive apex predator. “[Asian Giant Hornets] are a known pest of honeybees.”

While the hornets’ arrival could be devastating to the local honeybees, Looney said does not believe they will completely decimate the bees’ population.

“If [the hornets] become established and can reach populations they have in their native range, they will cost beekeepers money and heartache,” Looney said. “For some, the cost and effort of protecting hives could be too much.”

One longtime beekeeper told Looney he was getting out of the business after the reported attack on his hive. Looney emphasized that it has not been confirmed the hive was attacked by hornets.

WSDA has sap-baited sticky boards available to trap queen hornets. There is also information on the agency’s website about other types of traps. To learn how to build a trap, visit https://bit.ly/2yHUKwr. Looney explained that while becoming a part of the WSDA trapping program is a big commitment, it would help to expand the agency’s ability to track the invasion. Resources include obtaining materials to build and maintain traps; logging the traps on WSDA’s online mapping system; checking traps weekly for at least 17 weeks through the summer and fall; and submit any collected specimens to WSDA. More information can be found at https://bit.ly/35FUEl4.

Brouwer emphasized that due to the hornet’s powerful venom, it is recommended that people contact either an extension agent or WSDA to handle any found nest rather than trying to kill the hornets themselves.

Honey bees are not the only insect the hornets prey upon. In their native habitat, the Vespa mandarinia diet consists of 60 percent beetles, according to Looney. Wild bees like bumblebees have not been identified as a major food source.

“Researchers in Japan don’t describe [Asian Hornets] as especially agile, so there should be many bees species they just can’t catch,” Looney said. “I would hope things like ground-nesting bees might be relatively safe.”

Taking and sending photos is incredibly important, Looney said. To report sightings, visit https://bit.ly/3bdzcEX.

“Without a picture, we can’t decide where to spend our limited resources, so take a picture. Even very bad pictures often have enough information for us to make an ID so don’t hold back and keep those pictures coming,” Looney said.

For more information, visit https://bit.ly/3fwwtde, or the WSU Extention Office at https://extension.wsu.edu/sanjuan/.