Look Out for Emerald Ash Borer

“I have recently heard about an insect pest that is wreaking havoc on ash trees in the northeast. What is this pest and will it be headed our way?”

Yes – unfortunately, we are dealing with yet another invasive pest, the emerald ash borer (EAB). This insect is already in Georgia and Tennessee, so it’s just a matter of time before it will be discovered in Alabama.

Emerald ash borer

Emerald ash borer (Agrilus planipennis). Photo: Leah Bauer, USDA Forest Service Northern Research Station, Bugwood.org

The EAB is an exotic invasive from Asia that was discovered in Michigan in 2002 and has been recorded in 27 states and 2 Canadian provinces.

Since its discovery EAB has killed hundreds of millions of ash trees in North America. Affected species are black, white and green ash (Fraxinus nigra, Fraxinus americana, and Fraxinus pennsylvanica). EAB has recently been found in white fringetree (Chionanthus virignicus), as well. Consequently, regulatory agencies and the USDA have been required to establish and enforce quarantines and fines to prevent potentially infested trees, logs or hardwood firewood from moving out of areas where EAB occurs. This insect has cost municipalities, property owners, nursery operators and forest products industries hundreds of millions of dollars.

What is this pest’s mode of action? The EAB adult females deposit their eggs on the bark of ash trees, usually high in the canopy of trees in the thin branches. When the larvae hatch, they bore into the tree and feed on the inner bark. The feeding disrupts the nutrition system of the tree and as more larvae infest the tree, this causes a slow death, usually 2-4 years from the time of infection. At the time you realize you have this insect in your forest or landscape, it will be too late for any measure of control.

At spring emergence, adults leave a D-shaped hole in the bark of the infested tree. Since woodpeckers like to feed on EAB larva, heavy woodpecker damage on ash trees may be a sign of infestation.

Although EAB can fly, its flying radius is fairly minimal, but where our awareness of these insects comes into play is when we could be the ones transporting them. The public can be a valuable asset in slowing the spread of EAB and preventing the pest from entering non-infested states.

emerald ash borer in alabama

Emerald ash borers (Agrilus planipennis). Photo: Debbie Miller, USDA Forest Service, Bugwood.org

This time of year people are heading to the mountains and may pack fire-wood to take or purchase firewood upon arrival. Check the map and know where the EAB has been found. If you are in an area that is noted as having EAB, do not buy firewood or take firewood from that area to another. If you do buy firewood, use it only in the county where you bought it. Ash firewood that has dried naturally can still harbor larvae.

Below is a link to view where the EAB has been identified: http://www.emeraldashborer.info/documents/MultiState_EABpos.pdf

Regarding EAB, researchers and regulators can do their part, but we also need you the citizens. For the latest information on Emerald ash borer, please visit http://www.emeraldashborer.info/.

By Bethany O’Rear, Regional Extension Agent, Alabama Cooperative Extension System.  Contact Bethany at bethany@aces.edu.

The Alabama Cooperative Extension System (ACES) operates as the primary outreach organization for the land-grant functions of Alabama A&M and Auburn Universities. ACES is committed to affirmative action, equal opportunity and the diversity of its workforce.  Educational programs of ACES serve all people regardless of race, color, age, sex, religion, disability, sexual orientation, or national origin.



Alabama Extension

The Alabama Cooperative Extension System operates as the primary outreach organization for the land-grant functions of Alabama A&M and Auburn Universities and answers home-gardeners' questions each week on Birmingham Gardening Today.

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