PORTLAND, Ore. (KOIN) – Officials in Washington state hope there’s a little less buzz when it comes to Asian giant hornets in 2022. That is, they hope the work they did to eradicate the invasive species sometimes referred to as “murder hornets” in 2021 will pay off.
In August and September 2021, the Washington State Department of Agriculture (WSDA) located and exterminated three Asian giant hornet nests. There haven’t been any other detections since the nests were removed.
Researchers also determined in early January that all three nests were related to the nest they eradicated in 2020. Karla Salp, the public engagement specialist for WSDA, said this is an encouraging sign there aren’t other hives out there.
“It shows that they all stemmed from that nest, and also more importantly, there was no crossbreeding with other nests that we had not detected. So, if we had gotten some crossbreeding DNA evidence, we would have known that there were other nests out there,” she explained.
Salp was careful to say that “the lack of evidence is not evidence of lack.” In other words, just because they don’t have evidence of other nests doesn’t mean there aren’t other nests out there.
However, another positive sign was that in every 2021 eradicated nest, there was a mature queen inside and that was the only queen. This means WSDA reached the nests in time before the queens were able to reproduce new virgin queens that could potentially go out and start new nests.
Salp credits this to timing. The 2021 nests were discovered in August and September, earlier in the season. The 2020 nest was eradicated toward the end of October and there were almost 200 queens in that nest at the time. Salp said some of them could have flown away and started the new nests they found the following year.
Right now, in January, the hornets are overwintering, which means they’re fairly dormant. The queens start emerging in early spring and WSDA says that will be what truly determines if their efforts to take down the invaders have been truly successful.
Salp said WSDA will start making a plan for 2022 in late winter or early spring. So far, all hives have been discovered in the same area east of Blaine, Washington, which leaves WSDA hopeful they haven’t spread far.
WSDA has used radio trackers to locate the nests. They either go out and capture a hornet after receiving a report of a sighting or they’ll use a live hornet caught in a wasp trap. They’ll cool the hornet to a temperature where they aren’t active and will tie a radio tracker to them and let them go. They’ll then follow that tracker to locate the nest.
Salp said there’s been a lot of interest from the public in wanting to help track the invasive insects and she credits that to much of WSDA’s success.
“We have found that people, just keeping their eyes open and reporting sightings to us, you know, getting a photo of what they’re seeing and sending that into us, that is actually more effective than our trapping,” she said.
She said WSDA is getting more detections from public sightings than they are from the tracking system itself.
Asian giant hornets, which are invasive pests not native to the U.S., prey on other insects like honeybees. A small group of hornets can wipe out a honeybee hive in just hours. That’s why WSDA is so determined to remove them from the area.
Salp said things grew quiet after the third nest was dealt with in 2021, but she said you never know if they’ll emerge again in 2022. She encourages anyone who sees an insect they believe might be an Asian giant hornet to take a photo of it and report it to their state’s invasive species manager.