Emerald Ash Borer

Another insect from Asia has infested our trees.  The Emerald Ash Borer (EAB) was first found in dying ash trees in southeast Michigan.  It has since been found in Ontario, Ohio, Maryland and in Virginia.  The EAB most likely arrived to the US inside wooden pallets shipped from Asia.  Although this insect is very mobile, human activity such as collecting firewood and shipping nursery stock has spread the insect to the other areas.  Officials feel this insect is a very serious threat to our area.

Wisconsin's forests have a large number of White, Green and Black ash trees.  These same species do well as an urban street tree and as a landscape plant.  The tree is killed as the larva bore in to the tree severing the conducting tissue for water and nutrients.  The tree will begin to die from the top down.  Adult beetles will exit the tree through a characteristic "D" shaped hole approximately the size of a pencil.

Although there are several problems with our village ash trees, which can cause the tree to die, we would like to be notified if the "D" shaped exit holes are found.  For now, the Emerald Ash Borer has not been found in Wisconsin.  Currently, the best defense is detection and removal of infected trees.  No pesticides have yet to be recommended.  Finally, if you are going to plant a tree, it may be best to consider choosing a non-ash species.

For more information, go to: