EMERALD ASH BORER (EAB)
Agrilus planipennis Fairmaire

What is the Emerald Ash Borer (EAB)

The Emerald ash borer (EAB) is an exotic beetle that was discovered in southeastern Michigan near Detroit in the summer of 2002. The adult beetles nibble on ash foliage but cause little damage. The larvae (the immature stage) feed on the inner bark of ash trees, disrupting the tree's ability to transport water and nutrients.

The Emerald ash borer probably arrived in the United States on solid wood packing material carried in cargo ships or airplanes originating in its native Asia. Emerald ash borer is also established in Windsor, Ontario, was found in Ohio in 2003, northern Indiana in 2004, and northern Illinois in 2006.

Identification

The Emerald Ash Borer, known in scientific circles as Agrilus planipennis, is a member of the beetle family Buprestidae, or Metallic Wood-Boring Beetles. Like EAB, many species in this group are bright and shiny. The larval stages are commonly known as flat-headed borers.

There are approximately 675 species of buprestids in the US and Canada. The genus Agrilus, one of the largest in the family, has approximately 161 species in the US and Canada. However, unlike our native Agrilus species that normally only attack stressed or declining trees, EAB will attack healthy trees and kill them in one to four years. EAB is native to northeastern China, Korea, Mongolia, Japan, Taiwan, and far eastern Russia.

Since it's discovery, EAB has:

• Killed more than 20 million ash trees in Michigan, Ohio and Indiana. Most of the devastation is in southeastern Michigan.

• Caused regulatory agencies to enforce quarantines ( Ohio, Indiana, Michigan) and fines to prevent potentially infested ash trees, logs or firewood from moving out of areas where EAB occurs.
• Cost municipalities, property owners, nursery operators and forest products industries tens of millions of dollars.

What you need to know about EAB

•  It attacks only ash trees (Fraxinus spp.).
• Adult Beetles are metallic green and about ½-inch long.
• Adults leave a D-shaped exit hole in the bark when they emerge in spring.
• Woodpeckers like EAB larvae; heavy woodpecker damage on ash trees may be a sign of infestation.
• Firewood cannot be moved in many areas of Michigan, Ohio, Illinois and Indiana because of the EAB quarantine.

What is Being Done

• A concerted effort to stop EAB has been launched by state and federal officials.

• Research is being conducted at universities, as well, to understand the beetle's life cycle and find ways to detect new infestations, control EAB adults and larvae, and contain the infestation.
• Eradication efforts by state and federal agencies in Michigan, Ohio, Indiana and Canada are under way to prevent small infestations from growing into large infestations.
• Quarantines are in place to prevent infested ash firewood, logs or nursery trees from being transported and starting new infestations.

Control Measures

Scientists are studying methods of controlling EAB. The latest information on insecticide evaluations can help homeowners, arborists and landscapers decide if and how they can treat trees for EAB in certain areas in southeastern Michigan.

EAB Biology & Control Options (pdf)

IMPORTANT NOTE:

If your tree is located within an area designated for eradication or suppression activities, it may be removed by regulatory agencies even if it has been treated. In those cases where government-ordered tree removals occur within the contiguous EAB quarantine counties, consideration will be given to ash trees treated by certified applicators utilizing methods and materials recommended by Michigan State University.

If your ash trees are located outside of this area in Michigan, Indiana or Ohio, using insecticides may not be recommended. If you are not sure about the regulatory status of your area or whether you should consider insecticides, please contact your county Extension office.