Asian giant hornets spotted in western Washington

COUPEVILLE — State officials are asking Washington residents to report sightings of the Asian giant hornet, also known as the Japanese giant hornet, known for killing honeybees.

The Asian giant hornet can be from 1.5 to 2.5 inches in length, according to Tim Lawrence, WSU Island County Extension director. It is the largest hornet in the world.

“There are a lot of (insects) that look similar,” Lawrence said. “It is distinct in the head. It is very yellow. If you see a very large wasp and it has a yellow head, the (state department of agriculture) would be interested in talking to you.”

The giant hornet is native to Asia. In Japan, they are a major problem. The hornet attacks honeybee colonies, killing the entire hive and eating the pupae and larvae, together known as the brood.

No one knows how the Asian giant hornet got to the United States.

“There is speculation that it could have come over on a cargo ship,” Lawrence said. “Someone might have purposely introduced them. We don’t know.”

The hornets have only been spotted on the west side of the mountains, in the area approximately between Blaine and Bellingham. So far, no giant hornets have been spotted on the east side of the state.

The Asian giant hornet only spreads into a new territory at the rate of 15 miles per year. Since the hornets only recently arrived, it is probable that there currently are not any in the east side of the state yet, which the WSDA would like to see continue.

“That’s why the WSDA is putting out so much effort right now,” Lawrence said. “It would be great if we were able to find all of them and destroy them. That’s a difficult task.”

The giant hornets pose what could be a major problem for raspberry and blueberry growers in Whatcom County. With the introduction of the giant hornet, beekeepers are going to have to make some decisions about the way they do pollination in the area.

“Beekeepers are going to have to make the decision of if they will trap the hornets or move the bees,” Lawrence said.

In Japan, beekeepers use sticky traps to catch the giant hornets. Once stuck, the hornets release a pheromone that attracts other giant hornets to the trap. They also have designed traps for small bee hives that trap the hornets as they come out the top of the hive. But after some use, the hornets figure out the trap and will not enter the hive. Instead, they will wait at the bottom of the hive and grab honeybees there.