The emerald ash borer (EAB) is an exotic pest of ash trees. It is a recent introduction to the United States. EAB first was detected near Detroit, Michigan, in 2002 and probably arrived in wood packing material originating in Asia. It now has been detected in Michigan, Iowa, Kentucky, Minnesota, Missouri, New York, Ohio, Pennsylvania, Virginia, West Virginia, Wisconsin, Indiana, Illinois and Maryland as well as Ontario and Quebec. Millions of ash trees have been destroyed by this beetle causing tens of millions of dollars in losses to municipalities, property owners, nursery operators and forest products industries. Since its accidental introduction into the United States and Canada in the 1990s, and its subsequent detection in 2002 , it has spread to 14 states and adjacent parts of Canada. It has killed at least 50 - 100 million ash trees so far and threatens to kill most of the ash trees throughout North America.
Adult beetles are metallic green and about one-half inch long. Damage is caused by the immature or larval stage. EAB is relatively hard to detect because its larvae feed on the inner bark of the tree. It attacks only ash trees (Fraxinus spp.). Infested trees exhibit a top down die back, yellowing leaves and dense sprouting from roots and trunks.
Regulatory officials have established quarantines to prohibit the movement of infested ash trees, logs or firewood from infested areas. Quarantines generally extend a half mile in radius from sites known to be infested with EAB. Eradication of new infestations involves destruction of potentially infested ash trees.
Federal agencies and affected states have created web sites to provide updated information: