The emerald ash borer (EAB), Agrilus planipennis, has been a cause for concern for foresters and landowners alike in the United States. The beetle originated in Asia and was first observed in the United States near Detroit, Michigan, in 2002. It killed nearly 99% of ash trees near its place of original introduction. By 2018, EAB has been observed in thirty-five states and has killed hundreds of millions of ash trees in North America.
