The rapid response by the state was largely made possible by preparations that had been in place for several years. State surveys for Asian longhorned beetles had begun in 1996 at large container ports and pallet-recycling centers following the initial discovery of beetles in New York, and state entomologists had received training from the New York program So when the call came, they were ready to react.
A second beetle at the Tukwila nursery soon announced its presence after the WSDA team arrived, landing on the head of one of the state inspectors. Entomologists eventually captured a third beetle that day, but a fourth outmaneuvered the entomologist¿s nets and escaped into a nearby greenbelt, or wooded area.
The next day WSDA scientists carefully inspected Muth¿s maple trees and found a total of nine exit holes. From this evidence, they concluded that there were up to five beetles at large in the nearby suburban area--an area heavily populated with potential host trees. The final piece in the puzzle was put into place a few weeks later when dissection of the captured beetles showed that one was a fertilized female capable of laying eggs. This discovery established that the beetles had emerged from the trees long enough to both feed and mate, and therefore posed an infestation threat.
If the beetles could arrive in one shipment, USDA officials realized, they could also be in others. They expanded their detective work, quickly reviewing recent import records and suggesting state inspections of additional nurseries.
As a result, a week after the Tukwila beetles were discovered, state entomologists found a second introduction site at a nursery near Olympia, Wash. The seven bonsai maple trees involved had come from a completely separate shipment from Korea. Luckily, only two beetles were thought to have emerged, based on the exit holes found. One beetle had been caught by nursery personnel a few days before the state¿s inspection, and was later determined to be a female. Since these beetles mate only after emerging from the tree, the remaining insect at large, whether male or female, did not pose a reproductive threat.
Like a tiny rock that generates expanding ripples in a pond, the beetle release in Tukwila required a growing circle of response. "We spent a lot of time and effort looking at the logistics of a quarantine, sizes, and what kinds of things should be involved," explains Clinton Campbell, WSDA pest program manager.
The WSDA convened a Science Advisory Panel of local and national experts on longhorned beetles. The panel recommended aggressive action to stop the beetle from becoming established. In April 2002, the state finalized a plan to create a circular quarantine area a quarter of a mile in diameter around the Tukwila nursery. Potential host trees within an eighth of a mile from the nursery would be cut down and chipped, while trees in the next eighth mile would receive a systemic pesticide injection into the main trunk.
The tree cutting, which took place during July 2002, was both precedent setting and contentious. "For forest insects, this is the only case that I know of where we are taking control steps without knowledge that there is an actual infestation," says Haack, who was also a member of the Science Advisory Panel.
Most property owners reluctantly accepted the control plan, but three who lived across 10 lanes of highway from the nursery filed suit against the state to stop their trees from being cut. They felt it was unlikely that any beetles could have flown across such an imposing concrete and asphalt obstacle. "It was very difficult to convince people we had a problem, because we had nothing we could show them," recalls Brad White, WSDA managing entomologist. The dispute was later resolved in County Superior Court in favor of the state¿s right to destroy the trees.
Complicating matters, entomologists also had to contend with stringent state and city environmental regulations, because the site contained steep slopes and a wetland. To bypass the usual red tape, state officials drafted an emergency proclamation to allow the tree removal without the usual state and local environmental permits. Governor Gary Locke signed the proclamation in June 2002, just prior to the beginning of tree felling. The control program to date has cost approximately $1 million.