Emerald Ash Borer (IMAGE) Entomological Society of America Caption The emerald ash borer (EAB), a relatively new invasive insect pest, has killed tens of millions of ash trees throughout the eastern United States since it was first detected in 2002 in Michigan and Canada. Credit USDA Usage Restrictions Please credit USDA. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.