An adult emerald ash borer (Granville County).
On May 28, the N.C. Forest Service was un-warmly welcomed back from the long holiday weekend. During a standard check of emerald ash borer traps in Granville County, Forest Health staff and county personnel found the first evidence of emerald ash borer in North Carolina. N.C. Forest Service and NCDA&CS Plant Industry Division checked neighboring counties and found indications that the emerald ash borer is also present in Person and Vance counties.
While this finding was expected at some point, its presence in the state is nonetheless unfortunate. The emerald ash borer, which is native to Asia, is a wood-boring beetle that infests and kills all species of ash in the U.S. In North Carolina, four species of ash are threatened: green ash, white ash, Carolina ash and pumpkin ash.
Infested ash trees exhibit general decline in tree health. The crown thins and whole branches may die. In addition, there could be sprouts growing from the trunk of the tree, vertical splits in the bark, and/or increased woodpecker activity. When any combination of these symptoms is noticed, a closer inspection for direct evidence of the beetle should occur. The most obvious sign of the beetle is the quarter-inch D-shaped exit holes in the bark, caused when the adult beetle emerges from the tree. Upon removing the bark from the tree, winding, S-shaped larval galleries can be seen.
It is these larval galleries that sign the death warrant for an infested ash. As the larvae grow and eat the tissues of the tree, the tree loses its ability to transport water and nutrients. Effectively, the tree is girdled.
Clockwise from left: An ash with a thinning crown, a D-shaped exit hole, winding larval galleries (Granville County).
Most infested ash trees in the state will likely succumb to the beetles’ attack. However, for those willing to spend the time and money protecting their ash trees, insecticide options are available. These insecticides can protect the tree for one to two years, and should not be applied until the emerald ash borer is within 15 miles. The same insecticides may offer recovery for trees with minimal infestations and at least half of the tree crown healthy. Contact your county ranger for more information.
Granville, Person and Vance counties are now under a state quarantine to prevent the spread of this pest throughout the state. The movement of ash wood products and hardwood firewood outside the quarantine area is not permitted without a permit from the NCDA&CS.
This is the second time this year that the NCDA&CS announced the findings of a new invasive forest pest in North Carolina. In January, thousand cankers disease and the quarantine of walnut wood in Haywood County was announced.
To learn more about the emerald ash borer, visit the Forest Service’s FAQ on emerald ash borer.