News - Local News

POSTED: Monday, Jul. 06, 2009

Sign of summer: Small green traps go up in fight against gypsy moth

Crews are putting up 950 bright-green traps in Whatcom County as part of an annual effort to keep a non-native pest from taking hold in Washington state, where it could destroy hundreds of thousands of acres of trees.

Nearly 24,000 small cardboard traps have been put up in the state's 39 counties to trap European and Asian gypsy moths, which, in their caterpillar forms, are voracious eaters of foliage.

"They're very aggressive defoliators. They eat an awful lot of leaf material during their larval stage," said Jim Marra, managing entomologist for the state Department of Agriculture.

The tent-shaped cardboard traps are used to catch male gypsy moths, which are lured there by the scent of what they think is a female moth. The traps are checked every two to three weeks, then taken down in September.

Whatcom County is seventh highest in the state for the number of traps being put up. King County tops the list with 5,400 traps.

Two European gypsy moths were trapped in Point Roberts last summer, while 21 were caught statewide.

This year, four places in Whatcom County are being trapped heavily: a four-square-mile area near Sea Links Golf Course in Birch Bay and two locations in Point Roberts, one near Mill and Austin roads and the other near APA Road and Highland Drive. European gypsy moths have been caught in the past in those areas.

The other location being trapped heavily is the Port of Bellingham, because officials fears Asian moths might come off foreign ships docked there. Other ports in the state are receiving similar treatment for the same reason.

In fact, the state is on high alert for the Asian gypsy moth this year because U.S. Department of Homeland Security officials inspecting ships that came from infested ports found egg masses hitching a ride into Washington state.

There were 24 such "interceptions" along the entire Pacific coast last year, with 13 of them in Washington state, according to Marra.

"Last year was a very bad year. Apparently, Japan has some very high populations right now so ships visiting Japanese ports got infested with (Asian) gypsy moths," he said.

Deemed the worst forest pest ever to be brought into the U.S., the invasive critters will chow down on the leaves and needles of more than 500 species of trees and shrubs.

"You name a tree, it will attack it," said John Lundberg, spokesman for the state Department of Agriculture. "It's unlike the boll weevil that attacks cotton or the apple maggot that attacks apple trees."

Defoliated trees die or are weakened and, therefore, susceptible to disease.

The Asian variety is of particular concern because it attacks evergreen as well as deciduous trees and its female can fly up to 20 miles before laying her eggs - making it a much greater threat than the European gypsy moth, agriculture officials said.

The first European gypsy moths were caught in Washington state in 1974. The first was trapped in Whatcom County in 1982; a total of 138 have been caught here since then.

The first Asian gypsy moths were found in the state near the Port of Tacoma in 1991.

While there have been periods of gypsy moth infestation in the state of Washington, no permanent reproducing population has taken hold. State agricultural officials want to keep it that way, saying early detection is critical.

"Once a population becomes established, then eradication is no longer an option," Marra said.

That's partly because they reproduce rapidly - one female can lay up to 1,500 eggs.

Washington is one of the hottest states in the West for gypsy moth introduction, according to Marra.

That's because many people move here from infested areas and unwittingly carry egg masses on their vehicles or birdhouses; the state is home to alders, cottonwoods, hawthorns and oaks, some of the caterpillars' favorite foods; and temperatures are moderate.

The first European gypsy moths were found in the U.S. in Medford, Mass., in 1869. They were brought to the U.S. by a man trying to mate a gypsy moth with a silkworm.

They escaped and have since established themselves on more than 156 million acres in 19 states in the East and Midwest, where they have taken hold. In those areas, gypsy moth caterpillars have caused extensive damage, defoliating millions of acres and causing tens of millions of dollars in damage each year.

In Pennsylvania, where outbreaks have been greatest in recent years, some 1.5 million acres have been defoliated in the past two years.

Residents in states hit hard by the pests say they can hear the hungry caterpillars munching away on leaves at night.

LEARN MORE

Additional information about Washington state's 35-year-old gypsy moth control program is available by calling the gypsy moth hotline at (800) 443-6684. Or go online to agr.wa.gov.

WHICH GYPSY MOTH?

The state Department of Agriculture traps adult gypsy moths to track populations and to try to prevent them from becoming established.

Adult moths emerge from pupae after 10-14 days. They do not feed, and live a few days to several weeks. Adult moths are present in Whatcom County from July through August.

Female: White to cream-colored wings, tan body, about 2-inch wingspan.

Male: Smaller than females, about 1.5-inch wingspan, dark brown, feathery antennae.