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Emerald ash borer (Agrilus planipennis)

Emerald ash borer Description: Originally from Asia, was first discovered in July of 2002 in southeastern Michigan and Windsor, Ontario, Canada. So far, the distribution of the Emerald Ash Borer includes 35 states, the District of Columbia and five Canadian provinces. They were most likely brought to North America in infested solid wood packing materials.

Identification: Golden green or brassy color overall with darker, metallic emerald green wing covers. Adults measure 1/2 in (8.5-13 mm) in length. Females are larger than the males. Active from mid-May to late July. They feed on leaves, leaving irregular shaped patches with jagged edges. Larvae are flattened in appearance, consisting of 10 cream-colored, bell-shaped segments with a pair of brown pinchers at one end.

Hosts: White ash (Fraxinus americana), black ash (F.nigra), red ash (F. pennslyvanica), green ash (F. pennsylvanica var. subintegerrima) and several horticultural varieties of ash.

Life Cycle: May take 1 or 2 years to complete its life-cycle. Adult females may lay more than 100 eggs in a lifetime. Eggs are laid where the bark is rough, between bark layers or crevices. Eggs are 1.0 mm long by 0.6 mm wide and creamy white. Eggs hatch after 2 weeks.

Impact and Damage: S-shaped tunnels formed beneath the bark from larval feeding. Vertical splits in the bark. Adult emergence leaves D-shaped exit holes (3-4mm in diameter) in bark. Upper third of the tree dies back. Numerous shoots arise below the dead portion of the trunk.

Similar species: Larger and brighter green than any of the native Agrilus species. The two-lined chestnut borer (Agrilus bilineatus) and bronze birch borer (Agrilus anxius) are found attacking oak and birch trees, respectively.

Monitoring and rapid response: Emamectin benzoate (Tree-age), Imidicloprid (Merit, Xytect) and Dinotefuran (Safari, Transtect) insecticides.

Credits: The information provided in this factsheet was gathered from and the Massachusetts Introduced Pests Outreach Project.

Individual species images that appear with a number in a black box are courtesy of the network ( photo author credits may not be included due to the small display size of the images and subsequent difficulty of reading the provided text. All other images appear courtesy of Google (

Common Name:

Emerald ash borer

Scientific Name:

Agrilus planipennis


(Jewel beetle)