Ash Bark Beetle

What is it?

Ash Bark Beetle emergence holesAsh Bark Beetles are very small, oval shaped beetles that vary in color from grey to light reddish-brown to dark brown. The larvae inside the tree are tiny white, C-shaped grubs with brown heads. These insects attack all ash trees except Mountain Ash by tunnelling between the bark and wood. This burrowing causes the leaves to grow smaller than normal and to wilt and turn yellow between late June and early August.

What can I do?

Regular and proper pruning of dead or weakened branches will remove potential beetle breeding sites. After pruning , destroy dead, weakened or infested branches by burying them or burning them before bark beetle adults emerge in July.

Consider removing stunted and severely affected ash trees as they may spread infestations to healthy trees.

For more information, please view the Ask Bark Beetle (pdf) pages from our IPM Manual or our Ash Bark Beetle Information Sheet (pdf) .