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 that poses a threat to our ash trees if it arrives in Calgary. Currently there have been no detections in Alberta, but we continue to monitor for its presence.

​​​Learn more about common pests in Calgary​

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