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Clearwing Ash Borer


  • Larvae: Larvae hatch from eggs deposited on the rough bark of ash trees or on any tree with scarred or broken bark. After hatching, the larvae tunnel through the bark and feed on sapwood. As they mature, they bore into the heartwood. When full grown the borer larvae is creamy white with a light brown head, approximately 25 mm long.
  • Adult: Ash Borer adults emerge from infected trees during July and August. They have clear wings and look like a wasp.

Identifying infestations:

  • Damaged bark and wood: Larvae live from the root level up to one metre in height. As they feed, larvae expel a large amount of “sawdust” or frass which accumulates around their exit holes.

IPM Toolkit:

  • Preventive tools:
    • Protect tree bark from wounds or cuts which can result in scarring or broken bark.
  • Physical tools:
    • Wrap the trucks and basal parts of the main branches in mid-May with burlap to trap the emerging moths. Remove the burlap in August. Repeat annually for three years.
  • Biological tools: Not applicable
  • Chemical tools: Not applicable