Emerald Ash Borer

Facts About Emerald Ash Borer

• Native to Asia
• Most likely arrived in the U.S. in wood packing material
• Attacks only true ash trees (Fraxinus spp.)
• Adult beetles are metallic green, 1/2 inch long, 1/8 inch wide
• Adults leave a D-shaped exit hole in the bark when they emerge May through July
• Adults live for two to three weeks
• After mating eggs are laid in bark crevices of ash trees
• Eggs hatch in seven to 10 days
• After hatching, larvae tunnel under the bark creating S-shaped tunnels (galleries)
• Larval galleries cut off flow of water and nutrients to the tree, eventually causing death
• Woodpeckers eat EAB larvae; heavy woodpecker damage on ash trees can be a sign of infestation
• Larvae overwinter in chambers within sapwood of ash trees
• Firewood cannot be moved in many areas of the Midwest due to state and federal EAB quarantines

Identification & biology

The adult emerald ash borers are a metallic green color, approximately 1/2 inch long by 1/8 inch wide. They take one, and in some cases two, years to complete their life cycle.The adult beetles live for two to three weeks feeding inconspicuously on the margins of ash leaves in the tree canopy. After mating, the beetle lays eggs in bark crevices of the tree.

The eggs hatch in seven to 10 days. The larvae tunnel under the bark creating a characteristic serpentine path, disrupting the flow of water and necessary nutrients to the tree.

Signs & symptoms of emerald ash borer infestation

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	Crown dieback is usually the first noticeable symptom as disruption of the vascular system causes leaves to turn yellow and become scarce as branches die back in the upper canopy.
	1/8-inch wide D-shaped exit holes are characteristic signs left in the bark and branches as adult beetles emerge in the spring and summer. However, infestations usually start high up in the canopy and exit holes may not always be noticeable on the lower trunk until an infestation advances.
	Shoot sprouting and suckering often occur on the trunk or at the base of an infested tree.
	Vertical bark splitting often results as the tree responds to the larval tunneling beneath the bark.
	S-shaped galleries packed with frass (fine saw-dust waste) beneath the bark are a tell-tale signs that are created by feeding EAB larvae.
	Woodpecker activity may increase and be an important early indicator that EAB larvae are present under the bark.

What your forest preserves are doing

• Working with local and regional agencies to minimize spread of EAB & the damage associated with infestations.
• Conducting awareness training for staff involved with tree care throughout the district.

What you can do

• Familiarize yourself with the proper identification of ash trees and the EAB.
• Monitor the health of local ash trees for dying branches at the top of the tree (dieback).
• Purchase firewood locally from a known source.
• Be sure to use your firewood in the cold months so no emerald ash borers survive until spring.
• For more information, download these EAB posters.
  
  • Learn more about this species & how to identify it

Who do I contact if I find symptoms?