Winnipeg, MB – After nearly a decade managing spread of emerald ash borer, crews are responding to the first major detection of EAB activity since 2017.
Emerald ash borer (EAB) is an invasive beetle that feeds on and kills ash trees. Once the beetle is in a city, the entire ash population is at risk.
It was first detected in Winnipeg in 2017.
Officials initially expected the pest to wipe out Winnipeg’s ash population within 10-15 years as it has in other parts of North America. However, crews acted quickly to limit spread with proactive preventative injections and aggressive management.
We found and removed just 22 infected public trees between 2017 and 2025.
In response to a new population of EAB found earlier this year, we will remove susceptible ash trees from the Glenwood neighbourhood starting this week.
We are also revising our EAB management plan to respond to these new conditions.
Early detection is key to protection
Winnipeggers are encouraged to watch for and report signs of EAB activity. Early detection can help us limit spread and continue to preserve our ash population.
Signs of EAB activity include:
- Visible adult beetles – they are small (~1 cm long), metallic green, narrow (torpedo-shaped), and hairless.
- D-shaped exit holes in the bark
- Excessive woodpecker activity
- Bark splitting with “windows” where S-shaped galleries in the wood may be visible
- “Blonding” where sections of the dark outer bark has been removed by squirrels or woodpeckers, revealing the lighter wood underneath
Trees infested with EAB may not show symptoms for two to four years after activity begins.
The easiest way Winnipeggers can help slow the spread of EAB is to not move firewood – burn it where you bought it.
Winnipeggers can learn more about EAB and what we do about it at winnipeg.ca/emeraldashborer.