Emerald Ash Borer
Image Credit: U.S. Department of Agriculture
Emerald Ash Borer Emergency Order
For more information on invasive forest pests, visit our Emerald Ash Borer Pest Alert page.
- What is the Emerald Ash Borer (EAB)?
The Emerald Ash Borer (Agrilus planipennis) is a very small, wood-boring bark beetle. The destructive metallic green beetle is responsible for the death or decline of hundreds of millions of ash trees since it arrived in the United States and Canada.
- How did it get here?
The Emerald Ash Borer is native to China and eastern Asia. It probably came to North America in wood packing material in shipping crates. EAB was first discovered in North America near Detroit, Michigan in 2002. However, evidence suggests that is had been present here even longer. Since its discovery the beetle has spread to 31 states as well as parts of Canada.
- How does it harm trees?
Adult EABs, only a half-inch long, feed on ash foliage, but this is not usually harmful to the trees. It is the larvae of the beetle that cause the most damage. After hatching, the larvae begin feeding on the tissue between the bark and the sapwood. This feeding disrupts the movement of water and nutrients in the tree, eventually causing the tree to die.
- What trees are at risk?
In North America, the EAB attacks only ash trees (Fraxinus spp.), although there does seem to be a preference for certain species. In South Carolina, we have green, white, pumpkin, and Carolina ash trees. All of these appear to be at risk.
It also has been proven that EAB can complete its life cycle on the White Fringe Tree (Chionanthus virginicus), a U.S. native understory tree and also on cultivated olive trees (Olea europea).
- How can we prevent the spread of EAB?
EAB adults are strong fliers but usually only fly very short distances (about 1⁄2 mile). It is human behavior that has unknowingly contributed to the artificial spread of the insect. The movement of common ash products such as firewood, nursery stock, and lumber has been the primary means of the beetle’s spread. You can help by not moving firewood out of your local area and always buying firewood where it will be burned.
To prevent artificial spread of the insect, USDA has established quarantines to prohibit the movement of ash materials and hardwood firewood out of EAB infested states.
- How did we find it in South Carolina?
Agriculture officials set traps in the Palmetto State for more than a decade in order to detect insect's presence. The purple traps are baited with natural oils that contain compounds produced by ash trees when they are stressed. Research has shown that EAB is attracted to these compounds but they are not harmful to humans, pets or wildlife.
The Department of Plant Industry at Clemson University also works closely with the USDA Plant and Animal Health Inspection Service to monitor for EAB through visual surveys of ash trees both in the nursery industry and in the environment.
- What should I do?
If you suspect you have an exotic invasive pest or think you have an infestation, please contact the Department of Plant Industry or your local Clemson University Cooperative Extension Service office.
Department of Plant Industry
511 Westinghouse Road, Pendleton, SC 29670
103 Barre Hall Clemson, SC 29634