Emerald Ash Borer

Emerald Ash Borer

North America’s many Ash trees have come under attack from the Emerald Ash Borer (EAB).  This invasive insect pest is from Asia but was first discovered in North America (Michigan) in 2002. In 2009 it was detected in Kentucky and since then has continued to spread. This pest presents a serious threat to all ash trees in Kentucky including those planted in urban areas.  As EAB spreads across Kentucky, woodland owners will be faced with difficult decisions about how to respond.

What is it?

EAB (Agrilus planipennis) adults are 3/8 to 3/4 inch long and very narrow (about 1/5” wide). The wing covers are emerald green and the top of their abdomen, visible when the wings are spread, is metallic purple-red. When emerging from trees, they leave characteristic “D” shaped exit holes.

Newly emerged adults feed for several days, chewing irregular notches along leaf margins, before mating. Mated females will feed for another week or two before laying eggs in bark crevices or under bark flaps on the trunk. When the eggs hatch, larvae feed inside the tree and this is when EAB damage occurs.


What does EAB do?

EAB larvae feed just under the bark in the phloem and cambium, part of the vascular system of the tree that moves essential nutrients to different parts.  As they feed, larvae form characteristic large, serpentine-shaped galleries and severely damage the vascular system of the tree, eventually killing the tree.


  • Woodland Owners
  • Wood Industry

Advice For Woodland Owners Threatened with Emerald Ash Borer
As the Emerald Ash Borer spreads across Kentucky woodland owners will be faced with making decisions about how to respond. The link above provides an article from the Kentucky Woodlands Magazine to assist in the decision making process.

Insecticide Options for Protecting Ash Trees From Emerald Ash Borer
Click on the above link for a publication on protecting Ash trees from EAB. 

Threats To Forest Health: The Exotic Emerald Ash Borer 
Kentucky Woodlands Magazine Volume 1 Issue 1
Learn more about Emerald Ash Borer by clicking on the above link.

Emerald Ash Borer (EAB) FAQs for Kentuckians 
This website developed by UK's Entomology Department has been developed to provide information on the status of the emerald ash borer in Kentucky and some general information about the insect as it relates to spread and management.

Contact Information

Thomas Poe Cooper Building 730 Rose Street Lexington, KY 40546-0073