Invasive forest pests and pathogens

Invasive forest pests include insects and diseases that have been introduced accidentally into British Columbia, or have migrated here, and threaten the health of forest ecosystems.

On this page

• Spongy moth (formerly referred to as gypsy moth)
• Balsam woolly adelgid
• White pine blister rust
• Septoria canker

The Government of B.C. manages several invasive forest pests that have been recognized under federal regulations as "officially established" in Canada. Invasive species not officially established in Canada are managed by the Government of Canada.

Spongy moth

Spongy moths (formerly referred to as gypsy moths) are a threat to B.C.'s ecology and economy. The insect attacks both forests and urban trees. The presence of moths in a jurisdiction poses a quarantine challenge and a potential threat to the endangered Garry Oak ecosystem in southwestern B.C.

• Spongy moth

Balsam woolly adelgid

This tiny, wingless, aphid-like insect infests and kills or severely damages true firs in south coastal B.C. So far its range is limited but it is expected to expand to more areas throughout B.C. 

• Balsam woolly adelgid
• For more information, see Page 40, Field Guide to Forest Damage in British Columbia (PDF, 6.5MB)

White pine blister rust

This disease of five-needle pines has been established in Canada for about a century. It has significantly impacted the economic viability and survival of western white pine, whitebark pine and limber pine in B.C.

• White pine blister rust
• See page 122, Field Guide to Forest Damage in British Columbia (PDF, 6.5MB)

Septoria canker

The fungus Mycosphaerella populorum (Septoria musiva) causes leaf blight and, more importantly, necrotic lesions (cankers) resulting in stem breakage of hybrid poplar. All native B.C. species of Populus are somewhat susceptible. A Chief Forester's memorandum provides direction on poplar use in B.C.

• Chief Forester's Memo providing guidance on the use of hybrid poplar clones on crown land (PDF, 1MB)