Emerald Ash Borer

Insect Pest

Critical Threat

Affects: All ash species (Fraxinus) - green, white, black, blue ash

Photo: David Cappaert / Michigan State University (CC-BY-3.0-US (Bugwood))

Identification & Biology

Metallic green beetle native to Asia. Larvae feed under bark, cutting off water and nutrient transport. Tree dies within 2-5 years of infestation. Has killed hundreds of millions of ash trees in North America since 2002.

Current Status

Established throughout region. Virtually all untreated ash trees will die.

Affected regions:

Northeast & Mid-Atlantic Mountain West

States affected:

Colorado Connecticut Delaware Idaho Maine Maryland Massachusetts Montana New Hampshire New Jersey New York Pennsylvania Rhode Island Utah Vermont Virginia Wyoming

What Homeowners Should Do

Remove dead standing ash trees immediately - they become brittle hazards within 1-2 years. Preventive trunk injection (emamectin benzoate) can save high-value ash but requires biannual treatment.