This tree on M-134 is posted as a study subject for Emerald Ash Borer detection. About 12,000 ash trees throughout Michigan, including Mackinac County, have been strategically selected to serve as detection trees for the invasive Asian beetle, Emerald Ash Borer (EAB), which has killed more than 15 million trees in the state since 2002.

Field staff with the Michigan Cooperative EAB Response Project implemented the 2005 EAB detection tree program, which is an essential part of state’s continued efforts to contain the beetle.

So far, EAB has not spread into the Upper Peninsula. The Michigan Department of Agriculture has set up checkpoints at both sides of the Mackinac Bridge to confiscate any firewood or untreated wood being brought by visitors or shippers to the U.P.

As part of the detection 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.

MDA started a detection program last year by selecting certain ash trees in each county, except ones in quarantined areas. Removing a ring of bark around an ash tree’s trunk stresses the tree. Research has shown that EAB adults are likely to lay larvae on these trees, which gives a clear picture of where EAB is in the state. Researchers are still trying to find out why EAB is attracted to only ash trees, especially damaged or stressed ash trees.

The detection tree are four to eight inches in diameter and are 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 useful tools for early EAB detection.

Girdled trees such a these have been used to help contain the pest in an already infested area by attracting 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 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, say researchers, 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.