The emerald ash borer is about the size of a dime. Its larvae feed on the sapwood of ash trees.

By John McVey

Special to the Chronicle

BERKELEY SPRINGS – It’s a mystery how the emerald ash borer found Morgan County, but the invasive insect was reported in a housing development in the county earlier this year.

The infestation of destructive insects, which are native to Asia, was discovered by a homeowner in a southern Morgan County subdivision, said Jody Wilson, the West Virginia Department of Agriculture’s Plant Industries Division emerald ash borer regulatory officer.

The homeowner’s ash trees were dying. The ash trees’ leaves were turning yellow and the branches were curling back on themselves.

The infestation could be four years old, Wilson said, and there were quite a few insects found. A trap caught nine to 10 adults in short order, she said.

Besides the natural spread of the insects, the most common transportation method is insects hitching a ride on firewood brought into an uninfested area from an infested area, but that was not the case in Morgan County, Wilson said.

She said the insects could have been brought in on pallets during construction, but there was no real way of telling how they got to the Eastern Panhandle.

So far, the pests have not been found in any of Morgan County’s neighbors – Berkeley and Hampshire counties in West Virginia and Washington County in Maryland.

The insects were originally reported in Fayette County in southern West Virginia in October 2007, which remains the only other site in the state where the bugs have been found.

“We thought it would have been found in the Northern Panhandle,” Wilson said. “We’re really watching Ohio County.”

The borers have been found in areas of Ohio and Pennsylvania that border the Northern Panhandle.

However, the spread of the emerald ash borer throughout not only West Virginia, but all of North America probably is only a matter of time.

There is no widespread treatment to prevent the spread of the insects, Wilson explained. There only are some chemical pesticides that can be used to treat yard trees on a small scale.

“There’s nothing to do unless science comes up with something,” Wilson said. “We’ll probably lose the entire ash tree population North America in 25 to 30 years.”

Emerald ash borer

Smaller than a penny, the iridescent green and copper emerald ash borer beetle was found first in the Detroit metropolitan area in 2002, where the city’s ash trees had been dying off for several years, according to the U.S. Department of Agriculture’s Web site.

Since then the insects have spread throughout Michigan and neighboring Ontario, Canada. They have been found in Wisconsin, Illinois, Indiana, Missouri, Ohio, Pennsylvania, Maryland and Virginia as well as Quebec, Canada – and Minnesota was added to the list this year. The beetles have been identified in 59 ash trees in St. Paul.

It is believed the EAB made its way to Detroit on wood shipping material from Asia.

The female beetle lays eggs in crevices of the bark of the ash tree. The minute larvae bore through the bark into the sapwood, a tree’s new growth and where nutrients are carried to all parts of the tree.

As the worms feed, they leave little hollow trails behind until the tree is girdled, meaning all the sapwood has been eaten away. This creates a ring around the trunk, which cuts off the movement of nutrients to the rest of tree, killing it.

The trees die from the crown down.

The EAB attacks all 16 native species of ash trees in North America, Wilson said.

Females can travel from a half-mile to seven miles to mate and lay their eggs, she said.

Wilson related how a wide band was cut through a forest in Michigan to try to stop the migration of the EAB, but the insects were found across the barrier in a matter of days.

“The discovery of emerald ash borers in Morgan County illustrates just how effective these non-native insects and other invasive species can be at moving around undetected, until they begin to visibly damage our forests, urban environments and agricultural crops,” said West Virginia Commissioner of Agriculture Gus Douglass in a news release.

Ash trees

Ash trees make up about 4 percent of West Virginia’s forest cover, which is not a big portion of the state’s hardwoods – but the loss of any tree species is serious, Wilson said.

Six of the native species have commercial value, according to the USDA.

In West Virginia, the trees were harvested and sold, but the export of ash lumber out of the state has been halted, because of a quarantine placed on the state by the USDA to try to prevent the spread of the insects, she said.

In-state movement and sales still are allowed except to parts of the state from Morgan and Fayette counties, which are under a quarantine by the state Ag Department, she said.

However, the threat of EAB infestation has put a crimp in ash lumber sales, Wilson said, because lots of places are afraid to accept ash lumber from anywhere now.

Ash trees are very popular as urban trees and for residential landscaping, she said.

“The national urban impact from EAB could exceed $20 billion,” the USDA estimates.

The trees play an important part in the health of streams, growing naturally along stream banks, she said.

Ash wood is lightweight, but very strong, which makes it ideal for baseball bats, hockey sticks and oars, according to the USDA Web site. Most of the wooden baseball bats made in the United States are ash.

The wood also is used for flooring, furniture, tool handles and supplies for dairies, poultry operations and beekeepers.

Some of the highest densities of ash trees are found in the Eastern Panhandle, according to the USDA.

It is estimated that the EAB already have destroyed more than 25 million ash trees in North America.

The trap

Contrary to popular suspicions- such as aliens, the United Nations and Charlie Brown’s kite – the deep purple, triangular- or prism-shaped contraptions hanging from trees throughout the area are EAB traps.

Wilson said 16 traps have been placed in each of the state’s 55 counties. They are hung on ash trees.

“The traps have a lore made from Manuka oil that emits a scent that mimics a stressed ash tree that attracts the EAB,” she said.

The oil comes from the Manuka tree, which is native to Australia and New Zealand.

Made of plastic, the about 24-inch-long traps are coated with a non-toxic glue.

“They’re very sticky,” Wilson said. “Purple was shown to be the most attractive color to EAB.”

The traps were hung in May and will be taken down in September, she said. They also will be checked in July to see if any of the insects have been caught.

The state EAB programs are funded by the USDA. In the current fiscal year, West Virginia has received $233,000 from the USDA for the state EAB program, USDA spokeswoman Sharon Lucik said.

Firewood

The most common way the beetles are transported from one area to the another is by people taking firewood with them when they go camping.

“Please don’t move firewood around,” said Buddy Davidson, West Virginia Ag Department communications officer. “Buy your firewood where you camp and burn it all. Don’t leave unburned firewood behind.”

Pennsylvania does not allow firewood from outside the state to be used in the Keystone State’s parks.

Wilson added that it is not a good idea to transport firewood from one place to another anyway, because other destructive insects can be spread with the firewood.

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