EAB Identification

This insect gets its name because adults are a bright, metallic green. The adults live for a short time during summer months. 

EAB adult beetles and larvae can be difficult to find. However, it's still important to know what they look like so you don't mistake them for other green insects.

Visit OregonEAB to learn more about how to identify EABs.

Because EAB adults and larvae are difficult to find, the most reliable method of identifying EAB is monitoring the health of ash trees and keeping an eye out for the signs and symptoms of an EAB infestation.

• A sign is the physical evidence of a pest or pathogen.
• A symptom is a change in the tree tells you that it may be experiencing a problem.

EAB Signs and Symptoms

Symptoms of EAB include:

• Crown thinning or dieback from the top of the tree
• New shoots sprouting from the base or trunk of the tree below the main crown
• Cracks or separation of bark from the trunk
• Light patches of bark from woodpecker shaving

Signs of EAB include:

• EAB leaves characteristic D-shaped exit holes in the bark when they emerge in May and June. The holes are about ⅛ inch wide.
• Adult EAB beetles, measuring ⅜ to ½ inch long; slender, bullet shaped body; entirely green; smooth without ridges, hairs, bumps. When in flight (wings raised), the abdomen is bright coppery-red. Adults emerge from trees and are typically present from June through August; larvae are under bark and in sapwood most of the year.
• Long, skinny larvae within feeding galleries
• Serpentine feeding galleries under bark

Learn more about EAB signs and symptoms.

EAB Lifecycle

EAB Lifecycle.png

June - August

• Adults emerge from infested trees between June and mid August. 
• Early July is the peak of emergence in Oregon.
• Adults will spend the next 4-6 weeks feeding on ash leaves, mating and laying eggs. Adults lay their eggs in the bark of ash trees. 

July - September

• These eggs hatch in about 2 weeks and a larvae will burrow under the bark and begin to feed and grow. 
• The last adult EAB will die out by the end of September. 

October - April

• Cool temperatures from October through April cause the larvae to go dormant over the winter. 

May - June

• As temperatures warm up in May, the larvae finish their lifecycle, pupate, become adults, which then emerge from the infested trees throughout the summer.