Invasive insects destroying local ash trees

This pest is killing ash trees. [Emerald Ash Borer Network]

If you have an ash tree, it’s most likely infected with the emerald ash borer, an invasive insect that has killed millions of ash trees in the United States since 2003.

The Fairfax County Department of Public Works and Environmental Services is urging residents to hire a reputable tree company to eradicate these pests before their trees die or remove trees if it’s too late to save them.

“This is a rapidly advancing tree mortality and safety issue for property owners in the county,”  said Charles Layton of the Forest Pest Branch in the Fairfax County Urban Forest Management Division. “It’s unfortunate but true that every ash tree in Fairfax County is infested. We just can’t see it yet. There is a very small window of opportunity for treatment, but early treatment can be effective.”

Experts believe the half-inch long bright green beetle was brought to the U.S. from Asia on solid-wood packing material carried in cargo ships or airplanes. After being spotted in Ohio, the insects quickly spread and have now taken root in 23 states, according to the Emerald Ash Borer Information Network.

Quarantines and fines are in place to prevent the further spread of the emerald ash borer, but the damage so far has cost municipalities and property owners hundreds of millions of dollars. The environmental cost is incalculable.

Ash tree. [Gardening Know How]

It’s actually the beetle larvae that harms trees. They feed on the inner bark and disrupt the tree’s ability to transport water and nutrients, the network states.

“There is a safety concern because when ash trees die, the branches become very brittle,” says Fairfax County urban forester Rachel Griesmer-Zakhar. “The branches fall unexpectedly and can easily injure a person or pet, or damage a home or vehicle.”

To spot emerald ash borers, she says people should look for dead areas in the crown of an ash
tree, light-colored areas on the bark, and D-shaped holes on the bark. The Urban Forest Management Division uses the insecticide TreeAge on ash trees to kill the beetles.

Ash trees may be difficult to identify accurately, and residents can send a photo of a tree to [email protected].

Layton advises homeowners to hire a professional tree care specialist and avoid
people soliciting tree work door to door, as they could be incompetent
or scammers. Contact the International Society of Arboriculture to find a certified arborist.

For more information, contact the Fairfax County “urban forester of the day,” at 703-324-1770, the Fairfax County office of the Cooperative Extension, 703-324-5369, or Master Gardeners of Northern Virginia.