What Pests and Diseases Are Affecting or Spreading to Niagara?
Niagara has experienced significant canopy loss from invasive pests, and new threats continue
to emerge.
What’s Actually Happening
Established or historically damaging pests in Niagara include:• Emerald Ash Borer (Agrilus planipennis)
- Dutch Elm Disease
- Bronze Birch Borer
- Spongy Moth (formerly Gypsy Moth)
- Leaf miners
- Red-Headed Ash Borer
Emerging or spreading concerns in Southern Ontario:
- Spotted Lanternfly (SLF)
- Hemlock Woolly Adelgid (HWA)
- Box Tree Moth
- Spruce Adelgid / Sawfly
These pests can:
- Damage cambium
- Defoliate trees
- Stress or kill susceptible species
How to Handle It
- Monitor for unusual leaf loss or insect activity
- Confirm species identification
- Diversify plantings to reduce monoculture risk
- Seek professional evaluation if rapid decline occurs
Niagara’s canopy has already shifted significantly due to invasive pests.
Bottom Line
Invasive pests continue to reshape Niagara’s urban forest. Monitoring and species diversity
matter