Dying Ash Trees in Michigan
Ash trees go into decline or die because of disease, poor soil conditions or improper planting techniques. The Chinese beetle known as the emerald ash borer, or Agrilus planipennis, poses the greatest risk to ash trees in Michigan. Emerald ash borer infestations have already killed several million ash trees just in southeastern Michigan. Removal of the dying ash trees costs businesses, homeowners and local governments millions of dollars, according to the EmeraldAshBorer.info website. The effects of emerald ash borer mimic other diseases. Make certain you are actually dealing with an ash tree infested with emerald ash borer before you decide to treat or remove the tree. Does this Spark an idea?
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Features
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Michigan State University Extension says ash trees are often confused with elm, black walnut and hickory trees. Ash trees common to Michigan include black ash (Fraxinus nigra ), green ash (Fraxinus pennsylvanica) and white ash (Fraxinus americana). The trees grow 50 to 100 feet tall and 2 to 3 feet in diameter. Their grey bark develops deep furrows and ridges that form a diamond-shaped pattern. The compound leaves have finely-toothed or smooth edges. The foliage turns gold, purple, russet or yellow in fall.
Identification
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Emerald ash borer is well established in southeast Michigan and has spread to many areas in the Lower Peninsula. Emerald ash borers attack healthy trees but prefer to lay eggs or feed on stressed trees. Adult beetles are typically 1/2 inch long. They develop metallic-green wings and a copper-red or purple abdomen. They appear throughout the summer but are most common in June. The off-white larvae look like worms with bell-shaped body segments.
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Symptoms
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When emerald ash borer invades ash trees, the larvae feed on phloem below the bark and create serpentine-shaped galleries or tunnels. The galleries disrupt water and nutrient transport to the rest of the tree. New growth emerges at the root while the top of the tree canopy begins to die-back. The bark splits open to reveal the galleries. Woodpeckers flock to infested trees to feed on the larvae. Adult beetles create distinctive D-shaped holes as they exit the bark.
Considerations
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Insecticides effectively control emerald ash borer but treatments are costly and must be applied consistently. It is too late to save trees that have more than 50-percent canopy loss. Dead ash trees near power lines, sidewalks and driveways pose a safety risk and should be removed. Consider hiring a landscape or tree removal company to dispose of large ash trees. The Michigan Department of Agriculture says you can burn or chip the ash tree on your property in accordance with local and state regulations, but transport of ash wood outside quarantined areas is prohibited. All counties in the Lower Peninsula are under quarantine.
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References
- Michigan State University Extension: Ash Trees Decline: Ash Decline: Is it Emerald Ash Borer or What?
- Emerald Ash Borer: Emerald Ash Borer
- Michigan State University Extension: Distinguishing Ash from Other Common Trees
- "Trees of Michigan and the Upper Great Lakes" Norman F. Smith; 1997
- Michigan State University Extension: Signs and Symptoms of Emerald Ash Borer
- Michigan Department of Agriculture: I Think I Have EAB
