Emerald Ash Borer

emerald ash borer, (Agrilus planipennis), species of beetle (order Coleoptera, family Buprestidae) that is native to East Asia and became a serious pest of ash trees (Fraxinus) in North America. The insect naturally occurs in China, eastern Russia, Mongolia, Taiwan, Japan, and Korea and was introduced into eastern and central North America in the 1990s. Being responsible for the deaths of hundreds of millions of ash trees in the United States and Canada, the emerald ash borer is considered one of the most destructive insect pests ever to be introduced to North America.