Asian long-horned beetle

The Asian long-horned beetle disrupts a tree’s life support system, which results in a rapid decline of the tree within three or four years, and death of the tree within 15 years of infestation. During this time, some trees can become hazardous. Infested trees do not recover.

In its adult form, the beetle a has a black body, blue-white bands on long antennae (the “horns”), blue leg bands, and a starry sky pattern of white spots of various sizes on its wing casings.


In its larval stages, the Asian long-horned beetle is laid as an egg on the surface of a host hardwood tree and becomes a grub after two weeks. It enters through the tree’s bark slowly girdling the tree’s life support system beneath the bark. After a period of one to two years, the larva pupates and emerges from the tree as an adult beetle by chewing a relatively large perfectly round exit hole typically 10 millimetres in diameter.

Tree species in Canada susceptible to Asian long-horned beetle

The Asian long-horned beetle poses a serious threat to Canada’s forests and trees.

The following tree speeches are at high risk of the beetle:

  • Aesculus
  • Ash
  • Birch
  • Buckeye
  • Elm
  • Golden rain tree
  • Katsura
  • London plane
  • Maple
  • Mountain ash
  • Poplar
  • Sycamore
  • Willow

Preventing Asian long-horned beetle

Control of Asian long-horned beetle is overseen by the Canadian Food Inspection Agency (CFIA). Control and eradication is achieved by destroying all infested and high-risk species of trees within a defined control zone, usually a 400 metre radius from a confirmed host tree. The CFIA and municipalities work together to remove all trees of the species that can be hosts, whether the trees are infested or not, on private and public lands. Monitoring continues for several years, until the CFIA is satisfied the pest has been eradicated.

Learn more about preventing Asian long-horned beetle

Last modified:Thursday, July 04, 2024