The recent stretch of warm weather has moved forward the scheduled treatment to eradicate the Asian and European gypsy moths in Gig Harbor and throughout Western Washington.
The Gig Harbor treatment is estimated to begin April 29, according to Karla Salp, Community Outreach & Environmental Education specialist for the Washington State Department of Agriculture (WSDA).
To combat the highly invasive pest, WSDA will be spraying local foliage with Btk (Bacillus thuringiensis var. kurstaki) beginning about 30 minutes before sunrise and ending by 8 a.m. on the scheduled treatment day.
Btk is a biological insecticide that targets caterpillars and has been used safely for more than 25 years in the eradication of gypsy moth caterpillars.
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“We’ve chosen the safest product available that’s also effective at treating the moths,” Salp said. “It’s believed to not have any health problems for humans.”
Registered by the U.S. Environmental Protection Agency, Btk has been has been approved for use on organic food crops and is not considered harmful for humans, pets, birds, fish or bees.
While Btk is found naturally in the environment and is considered a safe product, Salp said the department still recommends that people and pets can minimize their exposure by remaining indoors during spraying and for the following 30 minutes.
Both species of gypsy moth, European and Asian, are destructive to trees, plants and shrubs and present a serious threat to the local environment, with Asian gypsy moths considered more worrisome because it can fly and rapidly increase its population.
An additional concern with the Asian gypsy moths, Salp said, is that this species will eat foliage from a wider range of trees, including evergreens. Unlike deciduous trees, which will become stressed by the loss of leaves but typically recover, needles lost from an evergreen tree do not grow back and tend to lead to the tree’s death.
Forty-two gypsy moths were trapped last year in Washington, including 10 Asian gypsy moths. One gypsy moth was found within Gig Harbor.
About 10,500 acres will be treated with Btk by WSDA in Western Washington, with each site treated a minimum of three times spaced between three and 10 days apart. Treatments will be applied by air and will be weather dependent as rain or wind could cause a change in application schedules. All treatments are expected to be completed by mid-May.
Residents in treatment areas can receive up-to-date information and treatment notifications by visiting agr.wa.gov/gypsymoth to sign up for notifications by e-mail, text message or robo call issued the day before any applications.