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24 gypsy moths trapped in Washington last summer

OLYMPIA – The gypsy moth, a destructive forest pest, continues to pop up in Washington. The Washington State Department of Agriculture (WSDA) caught 24 gypsy moths at 10 sites this summer.

Entomologists captured more than one moth at three sites. Nine moths were lured to WSDA’s small, green cardboard tent traps at Wauna, near Purdy. Other multiple-catch sites were: Kent (five moths) and Birch Bay near Bellingham (three moths).

The seven single-catch sites were at Key Peninsula near Purdy (Pierce County); Lake Wenatchee near Leavenworth (Chelan County); Marysville (Snohomish County); Ravenna neighborhood of Seattle (King County); near Chinook Pass (Yakima County); Sequim (Clallam County); and Totem Lake near Kirkland (King County). These areas will be heavily trapped next summer.

WSDA placed more than 25,000 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 and pupal cases. State entomologists will review the results of the inspections before determining whether to propose an eradication treatment for next spring.

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 relentlessly 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 infested states, primarily from the East Coast and upper Midwest. Some moths arrive on foreign ships docked at Washington ports.

The number of moths caught yearly in Washington varies widely – ranging from a high of 1,315 moths in 1983, to a low of 17 in 2002. WSDA caught 75 moths (18 sites) in 2006, 31 moths (15 sites) in 2005, and 68 moths (24 sites) in 2004.

Permanent populations of gypsy moth have never been detected in Washington. All moths caught this summer underwent a DNA analysis and have been determined to be the European gypsy moth.

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