Species Name: Emerald Ash Borer (Agrilus planipennis)
Description: A golden-green beetle, about a half-inch long, that feeds on several species of ash trees. In the larval stage, the beetle feeds on the phloem (inside the bark) of ash trees, killing that portion of the conductive tissue. A heavily infested tree will become girdled and die. Signs of Emerald Ash Borer include D-shaped exit holes, dying crowns, epicormic sprouts at the base of ash trees, S-shaped tunnels under the bark, and heavy woodpecker activity on the bole of the tree.
Similar species: Native adult Agrilus borers are smaller and feed on other tree species. Emerald Ash Borer adults have a distinctive shape, color, and size. In the larval stage, Emerald Ash borer feeds in an S-shaped pattern.
Origin: North-Eastern China. Southwest Michigan is considered the epicenter of invasion in the United States, as Emerald Ash Borer was discovered there in 2002, having been established a decade prior.
How it spreads: The spread of Emerald Ash Borer has been facilitated by the transport of infested firewood and other woody materials.
Extent in Michigan: All Lower Peninsula counties are quarantined; all Upper Peninsula except Iron, Ontonagon, and Gogebic counties are quarantined.
Why is Emerald Ash Borer a problem: When Emerald Ash Borer moves into an area, it can kill the majority of ash trees in a few years. Emerald Ash Borer has caused millions of dollars of damage to municipalities, who have had to remove and replace dead trees; it is estimated millions of dollars in timber value has been lost so far and is expected to be lost in the future. There are many ecological issues associated with the loss of a major species as well as cultural loss.
Management actions/options: Healthy, high-value trees may be treated with insecticide, though the injections must be reoccurring to prevent infestation. In un-infested forests, removing a significant portion of ash trees may help capture the value of timber and protect the remaining ash trees by reducing the density of ash. Firewood should not be transported.
REPORT IT: If you find Emerald Ash Borer in Ontonagon, Gogebic, or Iron county use the Midwest Invasive Species Information Network Reporting tool online
or download their reporting app
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