Field staff with the Michigan Cooperative Emerald Ash Borer (EAB) Response Project recently implemented the 2005 EAB detection tree program, which is an essential part of the Michigan’s continued statewide efforts to contain the beetle.

As part of this program, 12,000 ash trees were strategically selected at varying densities in every county in the state (except in the 20 quarantined counties of southeast Michigan) to serve as EAB detection trees. The selected ash trees were “girdled” – a process removing a ring of bark from the tree trunk – to stress the tree. Research has shown EAB adults are more likely to lay eggs on stressed trees, but will not lure the pest from long distances nor create new infestations.

The detection trees are four to eight inches in diameter and located in road rights-of-way, and in state parks and state and federal recreational areas. Trees chosen for girdling on private property were selected with permission from the property owner.

This EAB early detection program was first implemented in 2004 based upon the recommendations
of the National EAB Science Advisory Panel, comprised of some of the nation’s leading entomologists. These ash detection trees have proven to be a useful tool for early detection of EAB. Girdled trees such as these have been used to help contain the pest in an already infested area by attracting the beetles to the stressed trees.

“In 2004, this program helped us detect and implement containment strategies in six isolated areas of EAB infestations,” said Patricia Lockwood, EAB policy director for Governor Jennifer M. Granholm. “Early detection is critical to the successful containment of the beetle in Michigan and to the overall response strategy. Detection trees provide a clearer picture of where the pest is in the state and allows us to effectively implement the best response and containment efforts.”

Detection trees are tagged with “Do not disturb” signs. It is essential that the trees be left alone as any disturbance of the tree may lower the effectiveness of detecting the borer.

The detection tree recovery process is slated to begin in mid-September. During that process, the trees will be cut down and the bark peeled to look for larva. The recovery phase of this project should be completed in mid-November.

Emerald Ash Borer is an exotic, aggressive beetle native to Asia and was discovered in southeast Michigan in 2002. To date, the pest is responsible for the death or damage of approximately 15 million ash trees in the 20 quarantined counties and 19 quarantined outliers.

For more information about the detection tree program or EAB, please visit one of these Web sites: www.michigan.gov/eab or www.emeraldashborer.info. You may also contact your regional MDA office, or your local Michigan State University Extension or conservation district office.