The citrus long-horned beetle, anoplophora chinensis, is a serious tree pest native to Korea and China and was discovered in Tukwila. The beetle, with its shiny, jet-black body and long blue-black antennae, is a lesser-known, but close relative, of the tree-killing Asian long-horned beetle.

Citrus long-horned beetle females lay 200 eggs, each. Each egg is separately deposited into the bark of a tree. Beetle larvae hatch, tunnel into the heartwood and feed on the tree until they kill it. Both Asian and citrus long-horned beetles can kill a variety of hardwood trees such as maples, oaks, willows, and poplars.

Until the summer of 2001, the beetle genus had never been seen on the West Coast. As compared to its cousin, the citrus long-horned beetle is able to endure a range of climates and produce a greater number of eggs.

In early August 2001, a Tukwila nursery discovered an unusual beetle in a shipment of bonsai trees imported from Korea. The owner took a captured beetle to the U.S. Department of Agriculture Plant Inspection Station at SeaTac Airport. State biologists, who responded within hours, discovered more beetles and isolated the source of the infestation.

However, several citrus beetles escaped into a Tukwila greenbelt before all could be contained. A scientific advisory panel determined the citrus long-horned beetle was a great, if not greater risk than Asian long-horned beetle. If it became established in Tukwila, the insect profoundly could damage the environment and economy of not only the Pacific Northwest but also the whole of North America.

Because of the beetle’s year-long life cycle, state and federal officials knew they had less than 12 months to plan and carry out an eradication project. All the beetles must be found and killed before the next generation of beetles emerged and reproduced more widely in the greenbelt and residential area. That meant cutting down several thousand susceptible trees into which the escaped beetles may have flown and laid eggs.

Next, the immediate band of trees surrounding the cut zone received injections of a systemic pesticide to kill any beetles that escaped during the tree-cutting. State agriculture officials also worried about the artificial spread of the beetle in firewood, tree clippings, and other wood debris. Officials placed a quarantine a half-mile outside the beetle introduction site prohibiting Tukwila residents from moving beetle host material (wood, clippings).

The Department of Agriculture launched an education campaign to explain the necessity of the eradication project. Outreach activities included open house meetings, newsletter, and a monthly yard waste disposal day so that residents living in the quarantine area could bring their tree clippings to a chipping site for removal. In addition, residents whose trees had to be cut received financial aid to buy replacement plants.

The U.S. Forest Service funded the restoration of the greenbelt. The funding allowed the Department of Agriculture, in partnership with the State Nursery and Landscape Association, to offer residents coupons to offset their costs and purchase replacement trees and plants. For the next five growing seasons, the department maintained the firewood quarantine in Tukwila and surveyed the area extensively for any signs of the beetle.

A rapid response to a potential invasive species threat and adequate funding to stem the problem, allowed state and federal agencies to carry out the tree removal and tree injection program in Tukwila. In December 2006, after several years of collecting negative survey data, the Department of Agriculture removed the quarantine on Tukwila and officially declared citrus long-horned beetle eradicated from Washington.

The program’s success is attributed to the decisive and immediate action taken. The program went forward because the agencies involved were able to impress upon the public and elected officials the serious nature of the threat and the necessity for action.