The Emerald Ash Borer (EAB) probably arrived in the United States on wood packing material carried in cargo ships or airplanes originating in its native Asia. It is an exotic beetle that was unknown in North America until June 2002, when it was discovered as the cause for the decline of many ash trees in southeast Michigan and Windsor, Ontario, Canada. It has since been found in Indiana, Ohio, Maryland and Illinois.
The Emerald Ash Borer is smaller than a penny and has already wreaked havoc on millions of ash trees in the Midwest. Nearly 20 million trees in Michigan, Ohio, Ontario, Maryland, and Indiana have fallen victim to this deadly pest. The EAB can easily fly more than 1/2 mile during its flight season and is difficult to identify until it has already done its damage.
Adult beetles nibble on ash foliage but cause little damage. The larvae, however, feed on the inner bark of ash trees, disrupting the tree’s ability to transport water and nutrients. The larvae emerge from infested trees as bugs the first part of June.