Asian giant hornets could start emerging ‘any day now,’ says WSDA

Washington and British Columbian entomologists, along with scientists from the U.S. federal government, are suiting up for another year of battle with the Asian giant hornets.

The hornets have spent the winter hibernating, but queens will be emerging from any remaining nests within the next few weeks.

In a press conference Wednesday, Washington State Department of Agriculture (WSDA) representatives stated that they are once again focusing the trapping effort in northwestern Whatcom County, where all of the American sightings have been so far. The nest destroyed last year was found east of Blaine.

At the end of last year, entomologists suspected there were two other nests in downtown Blaine and the Birch Bay/Custer area, respectively. Those nests were not located before the hibernation period.

Washington gears up for second year of fight against Asian giant hornets

“The original nests are likely dead for the year,” said state entomologist Sven Spichiger during the press conference. “However, that means queens have the possibility of emerging from any nests that may have been in the area and forming new ones.”

A single nest can produce hundreds of queens. As Spichiger explained, the nest caught last year had 200 of them — and that nest was considered to be on the small side. He said we have to assume that any other nests in the area would contain at least that many queens — each one of those ready to fly off and establish its own nest.

“We would see queens start emerging anytime now on warm days. They’ll start the activity of founding new nests,” he said. “And so any queen that’s detected by the public and taken out of commission destroys the chance for another nest.”

This means time is of the essence for stopping the hornet expansion. People statewide should keep an eye out for the Asian giant hornets, but most especially those living in Whatcom, Skagit, San Juan, Island, Jefferson, and Clallam Counties. If you see a 2-inch orange hornet, report it to the Department of Agriculture right away.

The good news is that this citizen effort has yielded very real results. Last year, of the 31 sightings in Washington, about half were called in by residents.

“We can’t thank the citizen scientists enough,” Spichiger said.

The department announced that citizen scientists can now make their own DIY traps using one cup of brown sugar mixed with one cup of water as bait. This is more cost-effective than the type of bait most commonly used last year — rice wine and orange juice — though both kinds have demonstrated their effectiveness. People should not start putting up traps until July, to reduce the likelihood of catching local insects instead of Asian giant hornets.

Even if the invasive hornet population grows, Spichiger said they are still optimistic because the Asian giant hornets do not appear to have traveled beyond the northwestern corner of Whatcom County.

“Every year that goes by, we risk losing control of it. The pressure is on to eradicate as quickly as possible, but we also understand reality. … When I start seeing this pop up in multiple counties, multiple sites, that’s when we’ll know we’ve lost [the battle],” he said. “But right now, we are really just in northern Whatcom County.”

Total eradication remains the end goal for 2021.

“We will expend every effort and every resource that we have to make it happen,” Spichiger said. “Ultimately, that is our goal. … It’s as likely as we will make it, but it is a daunting task.”

The closed border is not stopping entomologists from Washington and B.C. from working together, since hornets have been spotted on both sides of the Peace Arch.

Paul van Westendorp, a provincial apiculturist with the British Columbia Ministry of Agriculture, Food and Fisheries, said British Columbia had six Asian giant hornet sightings last year, all just miles from Whatcom County in the B.C. Lower Mainland.

The first Asian giant hornet found in North America was caught in Nanaimo on Vancouver Island in 2019; however, van Westendorp said he is hopeful the island is now hornet-free.

“Since [2019], no single hornet has been sighted or collected. … If again there are no reports of these Asian giant hornets on Vancouver Island after two years of absence, hopefully we will be able to declare Vancouver Island free of Asian giant hornets,” he said.

Both countries believe the hornets may have accidentally come over from Asia on a container ship in 2019. It is not known whether the Nanaimo and Washington hornets are related, or if two different sets of hornets may have hitched a ride across the Pacific in the same year.

Asian giant hornets are commonly called “murder hornets” because of their tendency to decimate the hives of smaller bees. However, their stings are only deadly to humans in extremely rare cases.

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