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Emerald ash borer

The emerald ash borer (Agrilus planipennis) is a highly destructive invasive beetle that attacks and kills all species of ash in the genus fraxinus. It has already killed millions of trees in North America. The emerald ash borer is most commonly spread through the movement of firewood and other infested ash wood products, although it can also spread by flying. Research shows that adult beetles can fly up to 10 kilometers.

What you can do

Report an emerald ash borer sighting

Where it is

The emerald ash borer is present and regulated in:

See a map of all regulated areas, including a list of regulated states in the United States, and the latest information for this pest.

How to spot it

Signs of infestation on ash trees

Due to its small size, early detection of emerald ash borer is challenging. Visual inspection should instead focus on signs and symptoms of attack on ash trees. You may be able to see S-shaped lines formed by larva if the bark has been removed. Wood pecker feeding, epicormics shoots on the trunk, leaf yellowing and branch dieback are also good indicators of emerald ash borer presence. Eggs are laid on the bark of branches. Once they hatch, larvae will make their way through the bark, feeding on the inner bark and sapwood, eventually forming flat, 6 mm, S-shaped galleries which are filled with a fine brownish coating.

The larva can grow from 2 to 5 cm long and the width of the S-shaped gallery increases throughout its life span.

Infested ash trees in North America generally die after 2 to 3 years, but heavily infested trees have been observed to die after only 1 year.

Life stages of the emerald ash borer

The beetle has a metallic green back and an emerald green underside. Ranging from 8.5 to 14.0 mm long and 3.1 to 3.4 mm wide, the beetle is fairly small and difficult to spot. The body is narrow and elongated, and the head is flat. The eyes are kidney shaped and usually black.

Emerald ash borer larvae are white and flat, with distinctive bell-shaped segments, and can grow up from 2 to 5 cm long.

What we are doing

Import, movement and phytosanitary regulations

Biological control and surveillance

Emerald ash borer approved facilities compliance program

More information

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