State trappers are now placing brightly colored gypsy moth traps in trees, shrubs and other foliage in a continuing effort to protect Washington’s forests, agriculture and cityscapes from a destructive plant-eating pest. The traps are a key tool for detecting invasive gypsy moth across the state.
Twenty-five trappers hired by the Washington State Department of Agriculture’s (WSDA) are hanging 18,000 small cardboard traps in residential neighborhoods, business districts, ports and in rural areas. The traps will be checked every two to three weeks during the summer and early fall before being taken down in October.
John Townsend, state trapping coordinator for WSDA, looks forward to the annual trapping season. “Our trappers play a big role in keeping permanent populations of gypsy moth out of Washington. Trapping this season will detect any populations of gypsy moth that WSDA may propose to eradicate next year.”
The traps are non-toxic and contain a sex pheromone that attracts male moths. Inside the trap is a sticky coating that traps the moth—showing entomologists where a population of the pest may be developing.
WSDA has completed gypsy moth eradication efforts at the 43-acre site at South Hill Mall in Puyallup and at a 13-acre residential area of Eatonville. Five treatments with a biological insecticide were applied at the Puyallup project and four treatments were conducted at Eatonville. The timing of the eradication spraying, conducted between May 8 and June 28, was based on the emergence of gypsy moth caterpillars to prevent their development into moths.
“Cool, damp weather delayed the start of our treatments this year,” said Jim Marra, managing entomologist with WSDA’s Pest Program. “This is one of the longest gypsy moth spray seasons that staff can remember. We needed the caterpillars to hatch out and be a certain size before the spray can be effective.”
South Hill Mall and surrounding areas, as well as the Eatonville neighborhood near Eatonville Highway and Hilligoss Lane, will receive additional traps this summer to help determine whether any gypsy moth caterpillars escaped the treatments. These areas will be officially declared eradicated if no gypsy moths are detected for two consecutive years.
Gypsy moth has been detected in Washington every year since 1977, but permanent populations have not been established because of the state’s aggressive summer trapping and spring eradication efforts. Gypsy moths, which aren’t native to the U.S., arrive in the Pacific Northwest on ships from foreign ports or by hitching a ride with people traveling from other parts of the country. Nineteen states in the East and Midwest are permanently infested with gypsy moth, causing extensive environmental and economic damage each year.
The gypsy moth is the worst forest pest ever brought into the U.S. In its caterpillar form, the pest attacks more than 500 species of trees and plants. The caterpillar quickly strips trees and plants of leaves, destroying some and weakening others so they are susceptible to plant diseases. The caterpillar destroys wildlife habitat, degrades water quality and triggers costly quarantines of timber, agriculture and nursery products.
WSDA’s trap and pest detection programs include gypsy moth, apple maggot, sudden oak death, spartina, Mediterranean snail and Japanese beetle to protect Washington’s environment and to safeguard the agriculture, horticulture, nursery, timber and forest industries.
