An ash borer beetle, or emerald ash borer, is an invasive beetle whose larvae feed on the inner bark of ash trees. This disrupts water and nutrient distribution, contributing to the tree's demise.
Ash borer beetles arrived in North America around 2003 on cargo ships and planes arriving from Asia, hidden in packing crates made from ash wood. Approximately 25 states, from Michigan in 2003 to Arkansas in the summer of 2014, attribute the loss of millions of ash trees to ash borer beetles. Many state regulatory agencies and the United States Department of Agriculture have quarantined affected areas in an effort to curb the movement of these pests. Fines are imposed for transporting ash trees, logs or firewood from areas with potential infestations.