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18 gypsy moths caught in Washington in summer 2009

OLYMPIA — The gypsy moth, a destructive forest pest that causes millions of dollars of damage each year in the eastern and midwestern parts of the U.S., continues to show up in Washington. The Washington State Department of Agriculture (WSDA) caught 18 gypsy moths at seven sites this summer, the second lowest number of catches ever in the state. The lowest number was 17 catches in 2002.

Multiple moths were caught this summer at three sites, the Midland neighborhood near Tacoma (seven catches), Sunset Beach near Belfair in Mason County (five catches) and Everett (two catches). Single moths were detected in Bellingham, Issaquah, Renton and Tumwater.

WSDA placed 23,000 traps in the field in June and monitored them throughout the summer. WSDA employees are now conducting physical inspections of the multiple-catch sites, looking for additional evidence of gypsy moth activity, such as egg masses, pupal cases and cast skins. State entomologists will review the results of the inspections, along with the catch data, before determining whether to propose an eradication treatment for next spring. All moths caught this summer underwent a DNA analysis and have been determined to be the European gypsy moth.

The gypsy moth is one of America's worst forest pests. It attacks more than 500 species of deciduous and evergreen trees, has defoliated millions of U.S. trees and spreads quickly once established. Gypsy moths normally arrive in Washington in the form of egg masses attached to outdoor articles, such as picnic tables, birdhouses, and children's toys brought here from the19 permanently infested states in the East Coast and upper Midwest. Some moths arrive on foreign ships docked at Washington ports.

The number of moths caught annually in Washington varies widely, ranging from a high of 1,315 moths in 1983, to the low of 17 in 2002. WSDA caught 21 moths at 17 sites in 2008, 24 moths at 10 sites in 2007, and 75 moths at 18 sites in 2006.

Permanent populations of the gypsy moth have never been detected in Washington. WSDA's most recent treatment for gypsy moth took place in Kent in 2007.

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