Post navigation

Prev: (10/15/16) | Next: (10/15/16)

State says good news after Capitol Hill gypsy moth spray

Posted on by

Washington State Department of Agriculture officials aren’t declaring victory but the latest trap counts indicate its spring eradication strategy in the war against the invasive gypsy moth was a deadly one for the pest.

“While it is too early to declare the spring treatments a success, this year’s trapping results are very encouraging,” said Jim Marra, WSDA’s Pest Program Manager who oversaw the spraying program. “Two to three years of trapping after treatment are necessary before WSDA determines whether a treatment has been successful,” the announcement on the latest counts reads.

According to WSDA, more than 30,000 orange triangle-shaped traps placed on trees across the state following the spraying effort yielded hoped-for results: no Asian gypsy moths in the areas where planes dropped BTK, an organic pesticide. The “pheromone lure” traps designed to attract male gypsy moths collected the tiny winged pests through early September. Moths were captured in Clark (1), Cowlitz (1), King (7), Kitsap (8), Kittitas (1), Mason (1), Pierce (4), Spokane (1), and Thurston (1) counties, according to WSDA.

In April, an airplane flew above an area near the Miller Park neighborhood in early morning passes to deploy the organic pesticide. The state said Btk is not toxic to humans but recommended minimizing exposure.

Washington has been treating for gypsy moths since 1979. CHS wrote here about the differences between the moths, the history behind the infestation and why they’re such nasty neighbors.Gypsy moths caterpillars are incredibly voracious and not terribly picky, having been documented eating over 300 species of trees and shrubs. CHS first reported on the 2016 eradication plans in January and the presence of 22 moths found last year, six in 2014 and one each found in 2013 and 2012. State officials also found eight egg masses in the area last year, each of which can mean from 100-1,500 eggs.

The most likely explanation for how the moths ended up around the Hill is someone moving from out-of-state — likely from one of the 19 states in the mid-Atlantic, New England and upper Midwest where gypsy moths are well established. Females will lay their eggs on a flat surface, and the moths stay in that egg state for about nine months. “European gypsy moths usually come from people moving here, or bringing items from other states,” Karla Salp, community outreach and environmental education specialist for the Department of Agriculture told CHS earlier this year.

WSDA says the apparent good news in Washington follows the “largest gypsy moth outbreak in Eastern states since 1980, where the defoliation from hundreds of thousands of acres of trees could be seen from space this past summer.”

WSDA said it will make a decision on any 2017 spraying after it conducts “egg mass surveys” to look for signs of reproducing populations of gypsy moths in the catch areas, including around Capitol Hill and the Central District.

You can learn more at agr.wa.gov/gypsymoth.

Subscribe and support CHS Contributors -- $1/$5/$10 per month

Comments are closed.