Plant Industry - Emerald Ash Borer

Emerald ash borer (Agrilus planipennis Fairmaire; EAB) is a metallic-green beetle that bores into ash trees (Fraxinus sp.), ultimately killing them. The beetle is not native to the United States and was first detected in the United States near Detroit, Michigan in 2002. Since then, the beetle has been detected in Quebec and Ontario and 35 states in the US, including North Carolina in June 2013.

Emerald Ash Borer close up
Emerald Ash Borer on Penny for scale
David Cappaert, Michigan State University, Bugwood.org Howard Russell, Michigan State University, Bugwood.org

EAB lay their eggs on the bark of ash trees. When the eggs hatch, the larvae bore through the bark and into the cambium and feed on the transportation tissues, which disrupts the movement of nutrients and water within the tree, eventually killing the tree.

Adult EAB can fly at least ½ a mile from the tree where they emerge, but are more commonly spread when humans move infested materials such as nursery stock, logs, and firewood into uninfested areas. Symptoms of EAB in ash trees include a general decline in the appearance of the tree, such as thinning from the top down and loss of leaves. Clumps of shoots, also known as epicormic sprouts, emerging from the trunk of the tree and increased woodpecker activity are other symptoms.

Emerald ash borers overwinter as larvae. Adult beetles begin to emerge from May to June and can be found in the summer months. The adult beetle is ¼ to ½-inch long and is slender and metallic green. When the adults emerge from a tree, they leave behind a D-shaped exit hole. The larvae can also create serpentine tunneling marks, known as feeding galleries, which are found under the bark of the infested trees.

D-shaped exit hole for EAB
serpentine galleries
D-shaped exit hole
Serpentine galleries under bark
David Cappaert, Michigan State University, Bugwood.org William M. Ciesla, Forest Health Management International, Bugwood.org

EAB was first detected in North Carolina in Granville County in June 2013 and was subsequently found in Person, Vance and Warren counties. In March 2015, EAB was found in a stand of ash trees in Wayne County. Two more EAB detections occured in June 2015--one in Franklin County as a result of the Cerceris fumipennis Biosurveillance Program and the other in Wake County from a purple prism trap. During trap pull in July and August 2015, the beetle and evidence of its life stages were discovered in counties throughout the state. As a result of the widespread presence of EAB in North Carolina, Commissioner Troxler signed an emergency order placing the entire state under quarantine for emerald ash borer (see FAQ on EAB Quarantine & Compliance Agreements).    
 

EAB Statewide Quarantine

    
Entire state quarantined for emerald ash borer in North Carolina

 

Counties under Quarantine for EAB
All 100 counties

Home and landowners are encouraged to report any symptomatic activity in ash trees to their local N.C. Forest Service County Ranger. To find your county ranger, go to http://ncforestservice.gov/contacts/contacts_main.htm. Rangers can also suggest treatment options for homeowners.

For information regarding selecting and applying a pesticide to treat or protect ash trees from EAB, please read the Emerald Ash Borer Insecticide Guide produced by the N.C. Forest Service.