UNIVERSITY PARK, Pa. — The invasive emerald ash borer ... killing tens of millions of ash trees, causing one of the costliest forest insect invasions to date. More than 90% of all ash infested ...

In the decades since, the wood-boring beetle has spread east and west across the U.S. and Canada, killing tens of millions of ash trees ... Cottage Grove, Oregon; Tim Thibault, The Huntington ...

The invasive emerald ash borer, according to the U.S. Department of Agriculture, was first found in the United States in southeast Michigan in 2002. In the decades ...