Traps for gypsy moths set across county

Expect to see hundreds of these gypsy moth traps across Clark County. (Washington Department of Agriculture)

More than a thousand triangular football-size cardboard traps will be placed across Clark County over the next two weeks, as the state Department of Agriculture renews its annual hunt for destructive gypsy moths.

For 35 years, Washington and Oregon officials have kept the tree-munching pests from establishing a foothold in the Pacific Northwest. The moths' caterpillar form devours the leaves of trees and shrubs, weakening the trees and threatening forests.

When a moth is discovered, the state sprays the surrounding area with a biological insecticide.

The number of gypsy moths caught in Washington has varied from as many as 1,315 in 1983 down to just 17 in 2002. Twenty-one were caught last year.

Almost 24,000 cardboard traps, laced with an artificial female scent lure, will be placed statewide this summer. They will be checked every two to three weeks for males, entrapped while looking for love.

"A gypsy moth only lives two to three weeks as a moth," said John Lundberg, spokesman for the Department of Agriculture. "Then, what do they do? They don't eat. They copulate."

Individual moths live for only a year, but their damage endures.

In the absence of predatory insects and disease in the moth's home range, experts believe the moth is capable of weakening and ultimately killing wide swaths of trees in North America.

Washington spends about $1 million each year on gypsy moth control, Lundberg said, with about three-quarters of the cost going toward the trapping program.

Short of a widespread invasion, state officials are reluctant to introduce the birds and rodents that serve as the insect's natural predators in Asia and Europe.