There are many different pests or diseases that can infest Calgary's urban forest. Some are beneficial to the trees, but many are not.

Below is a list of the more common pests and diseases that can occur in Calgary's trees:

Invasive Threats to Calgary's urban forest

​Dutch elm disease is a fungus spread in elm trees by the elm bark beetle. Alberta is DED-free and works diligently to stay that way.​​

Emerald Ash Borer is an invasive beetle found in Eastern Canada which poses an extreme threat to Calgary's ash trees. Currently there have been no detections in Alberta, but we continue to monitor for its presence.

​​​Learn more about common pests in Calgary​