The Washington State Department of Agriculture has detected Asian and European gypsy moth presence in Western Washington — including in the Nisqually Valley and in Lacey, near Marvin Road just north of Interstate 5.
Gypsy moths can defoliate millions of acres of forest in a single year. In 2008, 30,900 acres of New Jersey forests died as a result of repeated gypsy moth defoliation. If gypsy moths become established in Washington state, costly quarantines will be imposed on our state’s nursery, forestry and Christmas tree industries. In addition, forest defoliation will destroy wildlife habitat, increase the risk of wildfire, affect water quality and can disrupt stream habitat for migrating salmon.
The state Department of Agriculture plans to conduct aerial spraying this spring to control gypsy moths, including in the two areas in Thurston County where Asian gypsy moths were found. Three to five applications of the insecticide Bacillus thuringiensis kurstaki (Btk) will be sprayed while the moths are in their caterpillar stage.
Agriculture officials believe this treatment poses very little risk to the public and the environment, and will effectively eliminate the moths. Experts at the state Department of Health have reviewed Btk, and concluded that it is not toxic to people and it does not harm water supplies. Btk is not known to cause human disease.
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The Department of Agriculture uses a process to evaluate and create a control program similar to the process that Thurston County uses for county-owned or managed properties. The process uses Integrated Pest Management principles to evaluate the pest, determine when control is needed, and identify the control measures that pose the least risk to public health and the environment. This review process is consistent with the goals of Thurston Thrives “to avoid exposures to materials and wastes that are harmful.”
While Btk has an excellent safety record, the Department of Health recommends that people in the spray areas take the following precautions:
▪ Remain indoors for at least 30 minutes after the spraying. It is a good idea to keep pets inside too.
▪ Children should wait until moisture from the spray has dried on grass and shrubs before playing outside and should wash their hands after playing outside. Gardeners should follow the same precautions.
▪ If you come into contact with the wet spray, wash the affected skin with soap and water. If wet spray gets into your eyes, flush them with water for 15 minutes.
People who are more susceptible to infections or respiratory irritation should pay particular attention to these precautions. This includes people with an underlying illness such as leukemia, AIDS or other immune system deficiency, people receiving radiation or chemotherapy, and people with asthma, emphysema or allergies.
People with concerns about exposure to Btk, their health, or their immune system should contact their health care provider.
The Department of Agriculture is conducting a public information campaign to inform citizens about the treatment proposal. It includes letters to residences and businesses in the affected areas, and an open house in each of the affected areas. Residents can sign up for text messages, emails or phone calls to be notified of treatment activities.
Reach Dr. Rachel C. Wood, health officer for Thurston and Lewis counties, at 360-867-2501, email@example.com, or @ThurstonHealth on Twitter.