Emerald ash borer

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Emerald ash borer (Photo: WTML)

Many homeowners, arborists and tree care professionals want to protect ash trees from the emerald ash borer (Photo: WTML)

Not yet present in the UK, this wood-boring beetle, native to Asia, has been found in Russia and North America, where it probably arrived in imported wooden packing material. It has killed hundreds of millions of ash trees in the United States alone since the 1990s so its introduction into the UK would cause devastation to ash which is already under threat from ash dieback. It is moving west from Russia at the rate of 25 miles per year.

What are emerald ash borer beetles?

Emerald ash borer (Agrilus planipennis) is a small bark boring insect which causes ash trees (Fraxinus excelsior) to die within two to three years of infestation. The increases in the global movement of wood and wood packaging means it poses a significant risk to UK woodlands.

Symptoms

  • Thinning or yellowing of foliage
  • Fissures in bark, 5-10 cm in length
  • Woodpecker activity, as the birds strip away bark to get at the beetles
  • D-shaped holes, 3mm in diameter, produced by emerging adults

Causes

Outlook

  • Risk of import on wood packaging or imported wood
  • UK Contingency plan in place
  • Early detection is difficult, no control measures once established
  • If this pest gets into the UK it would be devastating for our woodlands and trees

Report it

If you think you’ve spotted this disease please inform the Forestry Commission using the Tree Alert reporting tool. Three good-quality digital photographs are required to aid identification.

For more information visit the Forestry Commission.

Trees face huge challenges

With more new pests and diseases reaching our shores tackling pests and diseases is now an urgent priority

Learn about the threats