Living up to its name, the gypsy moth continues to wander in and around Washington.
"The gypsy moth is the most destructive forest pest insect ever introduced into North America," said Washington state Department of Agriculture pest program contact John Lundberg. "Our traps caught one in Sequim for the first time ever, but keep in mind one moth isn’t necessarily the start of a permanent population."
As caterpillars, the species consumes large amounts of plant life in the early summer and without natural predators in North America, the European moth’s populations have soared in areas like New England and the Midwest. It attacks more than 500 species of deciduous and
evergreen trees and has defoliated millions of U.S. trees.
In order to avoid permanent populations in the state, WSDA entomologists, or bug experts, place traps in communities statewide in June and retrieve the tent-shaped cardboard traps in September. Researchers placed more than 25,000 traps in trees across the state in 2007.
"The traps in no way eradicate the species or attack their numbers," Lundberg said. "We use them to track where they are going and possibly settling."
Lundberg said WSDA is likely to test more aggressively in the Sequim area to determine if the moth was a solo flier or a parent of thousands.
"The fact that we caught a moth shows that there is activity in Sequim, whether that means we will need to treat the area will likely be a decision based on next summer’s tests," Lundberg said. "Treatment involves the application of a biological insecticide."
If next year’s tests catch more gypsy moths, experts will begin looking for additional evidence of their presence, such as egg masses or pupal cases.
"Their eggs easily last through our winters and often are transported in from other areas," Lundberg said. "So you could have eggs on a spare tire and those little guys will emit a small silk-like strand to catch a ride on the wind to the nearest tree."
The Sequim moth marks the eighth to have been caught in Clallam County since 1989. The first moth found in Washington was in 1974. Lundberg emphasized that no community in Washington has had a permanent population of gypsy moths.
"Oregon and Washington have similar programs where we test, monitor and possibly treat the existence of the moths before they become permanently positioned in a community," he said. "Once they establish themselves, they spread very quickly and as an invasive species they have no natural predators and often do better when competing with similar species that originated from the area."
The moths came to the U.S. in 1869 under controlled conditions but eventually escaped and became permanently established in 19 states. The WSDA has more information on the topic and a list of captured gypsy moths available on its Web site http://agr.wa.gov/PlantsInsects/InsectPests/GypsyMoth/default.htm.
