A hemlock looper moth resting on a bright green leaf

Stanley Park forest management

About the moth

The hemlock looper moth is an endemic insect that experiences population outbreaks approximately every 15 years.

Its larvae hatch in the spring and aggressively feed on foliage, causing the most damage between July and October.

It feeds on coastal coniferous species which makes Stanley Park particularly vulnerable.

Hemlock looper moth outbreak

Stanley Park is experiencing a hemlock looper outbreak which has damaged many of its trees, including western hemlock, Douglas fir, and grand fir.

A significant portion of the park is affected, particularly near Lions Gate Bridge. This outbreak also affects parts of West and North Vancouver, where many trees are dying.

After recent droughts and hard winters, trees in Stanley Park are more vulnerable to the hemlock looper outbreak and less likely to recover.

What's happeningStanley Park progress updates

We have completed essential tree work across over 60 hectares of Stanley Park forest affected by the Hemlock looper outbreak.

This spring, we planted over 25,000 seedlings of a variety of species as part of our reforestation efforts to build a healthier and more resilient forest.

Managing the hemlock looper outbreak and wildfire risks

Hemlock looper populations usually decrease when the weather interrupts their life stages and when predators such as parasitic wasps and birds eat them.

Using pesticides is not an option because they harm other, non-target insects that live in the forest ecosystem.

We're addressing the outbreak and wildfire risks with support from a forestry consultant. Their expert report outlines a careful approach, focusing on risk mitigation and ecological enhancements for long-term forest health.

Stanley Park Hemlock Looper Impact and Wildfire Risk Assessment (4 MB)

In the meantime, we will continue to manage dead and dry trees that present public safety and wildfire risks. While this work is underway, access to certain trails and roadways in the park may be temporarily restricted. Follow signage and staff directions for safety.