Pilot Project in Michigan’s Upper Peninsula Aims to Keep More Ash Trees Alive
12/22/09
Contact: Robin Usborne
517-432-1555, ext. 169
or
Deborah McCullough
517-355-7445
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Andrew Storer
Michigan Tech
906-487-3470
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John Bedford
Michigan Department of Agriculture
517-373-4350
EAST LANSING, Mich. -- The emerald ash borer (EAB), an exotic wood-boring pest, continues to spread, killing millions of ash trees in Michigan and surrounding states. Now scientists and state and federal officials are working to find ways to slow the rate of ash tree death in EAB-infested outlier sites in Michigan’s Upper Peninsula as part of the SLAM – SL.ow A.sh M.ortality pilot project. Outlier sites are infestations of EAB that are well beyond the infested area in the state’s Lower Peninsula.
The research partners from Michigan State University (MSU) and Michigan Technological University (MTU), and officials from the Michigan Department of Agriculture (MDA) and the USDA Animal and Plant Health Inspection Service (APHIS), and forest health specialists from the Michigan Department of Natural Resources and the USDA Forest Service involved in the SLAM pilot project are continually surveying EAB infestations to track the spread of the pest and to develop ways to slow the build-up of the EAB population. The goal of the project is to delay the spread of ash mortality in the area. Lessons learned in the pilot project will benefit not only Michigan, but other states dealing with EAB.
“The data gathered this year in the communities of Moran and St. Ignace are giving us a better idea of the EAB population, how it grew and how it is spreading,” said Brenda Owen, SLAM project coordinator. “We know that EAB will never be totally eradicated, but we are developing ways to slow it down. If we can buy time, other control options may become available.”
In the St. Ignace area, EAB larvae were found in four areas this summer. One was just inside the state park boundary, another was in the city and two infested trees were outside the park and city boundaries. No EAB were found in the downtown of St. Ignace in ash trees that were girdled or had purple prism traps in them during the summer. Fifty trees in St. Ignace with no visible signs of EAB infestation were injected with insecticide.
The EAB survey size in Moran doubled this summer from a 3-mile radius to a 6-mile radius because of additional EAB finds in that area, according to Owen.
Survey methods to detect EAB included using purple prism “sticky” traps in ash trees. The traps are baited lures that may attract adult EAB beetles. They are placed in trees early in the summer when EAB beetles begin flying, then removed in the fall once the beetles are gone. Another method involves using ash trees themselves as “detection” trees. Researchers have shown that EAB beetles are attracted to stressed ash trees and lay more eggs on stressed trees than healthy ash trees. To survey for EAB, selected ash trees are girdled in spring by removing a band of bark around the trunk. This affects the ability of trees to move nutrients from the leaves to the roots and slowly starves the tree. In fall, the girdled trees are felled and the bark is removed to see if EAB larvae are feeding on the tree. Knowing which trees are infested and how many larvae are on the trees helps the SLAM partners monitor the growth of the EAB population. Partners in the SLAM project are also using insecticides to help slow the build-up of EAB populations. Once the data are gathered and processed, the approximate density and spread of the EAB population in a given area can be estimated.
The SLAM pilot project, which will continue in 2010, is providing new options for managing areas with low densities of EAB. Results will be shared with managers in other states such as Wisconsin, Minnesota, New York and Missouri, where EAB has recently been found.
Not only will the SLAM pilot project slow the rate at which EAB impacts ash trees, it also provides employment for another year for at least 15 Upper Peninsula residents.
More information on EAB can be found at www.emeraldashborer.info, or www.michigan.gov/eab.
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