BELLINGHAM, Wash. (AP) — A dozen traps to catch Asian giant hornets have been placed in multiple parks and green spaces in northwestern Washington state, adding to an already extensive effort to eradicate the invasive species.

The Bellingham Parks and Recreation Department has said nine volunteers have agreed to monitor the clear plastic bottle traps in 10 different areas in the city, The Bellingham Herald reported. The bottles contain a mixture of orange juice and rice cooking wine or sake intended to attract the hornets.

These 12 traps were set in Cornwall Park, Sehome Hill Arboretum, Big Rock Garden Park, Fairhaven Park/Hundred Acre Wood, Connelly Creek Nature Area, Euclid Park, Sunset Pond, Whatcom Falls, Galbraith and Northridge Park.

About 1,800 traps have already been placed, 600 from the Washington State Department of Agriculture and about 1,200 from citizen scientists, said Karla Salp, a department spokeswoman.

The traps were set after experts discovered two dead hornets in Bellingham on June 6 and near Custer on May 27, the first confirmed sightings of the species in the U.S. this year. Five Asian giant hornets have been found in Whatcom County since last winter.

Asian giant hornets — their Latin name is Vespa mandarina — are the world’s largest hornets. They are brutal to pollinators, known to decapitate honey bees, and by extension the crops the bees pollinate.

Asian giant hornets are native to mainland southeast Asia and Taiwan. Queens nest in the ground over the winter and emerge in April. Workers start foraging in late June.