May 11 2020 09:34 AM

The world’s largest hornet carries a painful, sometimes lethal sting.

Photo: Washington State Department of Agriculture

More than two inches long, the world’s largest hornet carries a painful, sometimes lethal sting and an appetite for honeybees. It is also the newest insect invader of Washington state, according to an article by Washington State University.

The Asian giant hornet, Vespa mandarinia, was sighted for the first time in Washington last December and started to become active in April. WSU researchers are working with the Washington State Department of Agriculture, beekeepers and citizens to find it, study it and help roll back its spread.

It is not known how or where the hornet first arrived in North America. Insects are frequently transported in international cargo and are sometimes transported deliberately.

At home in the forests and low mountains of eastern and southeast Asia, the hornet feeds on large insects, including native wasps and bees. In Japan, it devastates the European honeybee, which has no effective defense.

Hornets are most destructive in the late summer and early fall, when they are on the hunt for sources of protein to raise next year’s queens. V. mandarinia attack honeybee hives, killing adult bees and devouring bee larvae and pupae, while aggressively defending the occupied colony. Their stings are big and painful, with a potent neurotoxin. Multiple stings can kill humans, even if they are not allergic.

Beekeepers, WSU Master Gardener volunteers and other Extension clients are often the first detectors of invasive species. WSU scientists are now spreading awareness of the hornet to citizens and developing a fact sheet to help people identify and safely encounter the insects.

As partners with the Washington Invasive Species Council, they also urge citizens to download the WA Invasives smartphone app for quick reporting of sightings.

Scientists with the WSDA Pest Program are taking the lead on finding, trapping and eradicating the pest. WSDA will begin trapping for queens this spring, with a focus on Whatcom, Skagit, San Juan, and Island counties.

The agency plans to collaborate with local beekeepers and WSU Extension scientists and entomologists with WSU focusing its efforts on management advice for beekeepers.