Agrilus planipennis, the emerald ash borer, has killed hundreds of millions of ash trees in North America since its detection in Michigan in 2002. It kills all North American ash species — green ash (Fraxinus pennsylvanica), white ash (Fraxinus americana), black ash (Fraxinus nigra), and blue ash (Fraxinus quadrangulata) — in 3 to 5 years if untreated.
This is not a pest where you wait and see. By the time symptoms are obvious, treatment is less effective and sometimes too late.
