Eab

Emerald ash borer (EAB), Agrilus planipennis, is an invasive beetle in the family Buprestidae. Native to Asia, it was first detected in North America in 2002 near Detroit, Michigan, likely introduced through infested wood. Since then, EAB has established populations across much of the eastern and midwestern United States and into parts of Canada, where it attacks ash trees (Fraxinus spp.) including white, green, and black ash.

Adults are small, slender beetles about 8.5–14 mm long with a metallic green body. They lay eggs on the bark in late spring. Larvae hatch and tunnel under the bark, creating serpentine galleries that disrupt nutrient flow. Larvae overwinter beneath the bark; adults emerge the following season to repeat the cycle.

Diagnosis relies on canopy thinning, bark splitting, and distinctive D-shaped exit holes. Visible signs include serpentine larval galleries beneath roughened bark and woodpecker damage. Infested trees typically die within one to three years, causing ecological and economic losses in forests and urban landscapes.

Management emphasizes detection and containment. Quarantine and restrictions on movement of firewood and infested material aim to slow spread. For individual trees, systemic insecticides delivered by trunk or soil injections can provide protection. In forests, biological control programs release parasitoid wasps such as Tetrastichus planipennisi, Spathius agrili, and Oobius agrili. Monitoring uses visual surveys and purple traps to detect adult flight, guiding removal and treatment decisions.

Public awareness and rapid reporting support early intervention. Efforts continue to develop resistant ash taxa and diversify urban tree planting to reduce future vulnerability.