Emerald Ash Borer (EAB) has become a very destructive pest to ash trees throughout Wisconsin. It kills all native species of ash trees by feeding on the tissues under the bark, causing disruption to the flow of nutrients and water throughout the tree.
Treating ash trees with a trunk injection of Emamectin Benzoate every 2 years is the only way to protect your trees from infestation. In the Milwaukee area most of the untreated trees have either been killed or are rapidly declining due to EAB. If you have not treated your ash trees and you live in the Milwaukee area removal is most likely the next action that should be taken to avoid the trees becoming hazardous.
The pest is moving west from the Milwaukee area to Madison at an alarming rate. EAB is established and is building up in population. In the Madison area if you want to preserve your ash trees treating preventatively should be started as soon as possible. Treating ash trees before an infestation can avoid costly removals in the future.