News release

City’s Aerial Spray Program Begins

City services | May 17, 2018

With the warmer weather conditions, the City of Mississauga has tentatively scheduled its aerial spray program to begin May 23, 24 and 25. The spray will help manage cankerworm and gypsy moth caterpillar populations. Private and public lands in specific areas of Wards 1, 2, 6, 7, 8 and 11 will be sprayed.

Day 1: Block A – Wednesday, May 23 from 5 a.m. to 7:30 a.m.
Parts of Wards 6, 7, 8 and 11 as well as 150 metres north and south of the QEW in Wards 1, 2 and 7

Day 2: Block B – Thursday, May 24 from 5 a.m. to 7:30 a.m.
Parts of Ward 2

Day 3: Block C – Friday, May 25  from 5 a.m. to 7:30 a.m.
Parts of Wards 1 and 7

The City has drafted a detailed FAQ to address specific questions regarding the spray. The City will continue to share information about the spray at and via social media. Residents are also encouraged to sign up for aerial spray news alerts.

“The spray is contingent on leaves being at least 30 per cent expanded and caterpillar hatch out as close to 100 per cent as possible,” said Jamie Ferguson, Aerial Spray Project Lead for the City of Mississauga. “When those conditions are met, we then need to monitor weather for the right temperature, humidity, low wind and no precipitation in the immediate forecast.”

As a result, specific spray dates are chosen 48 hours in advance and they can be cancelled up to 12 hours in advance if weather conditions change. The City will issue notice to the public 48 hours before each treatment on the aerial spray website and provide up-to-date information through 3-1-1 and through the City’s Twitter channels (@CityMississauga and @MississaugaPF) and on Facebook (

Spray Locations
To find out if your home is in the spray area, please visit: Spray areas include:

  •  Birch Glen
  • Credit Reserve
  • East Collegeway
  • Erin Woods
  • Erindale Park
  • Erindale Village
  • Erindale Woodlands
  • Gordon Woods
  • Lakeview
  • Lorne Crest
  • Lorne Park Estates
  • Meadow Wood – Rattray
  • Mississauga Oakridge
  • Mississauga Road
  • Owenwood
  • Port Credit Village
  • Riverwood
  • Sawmill Valley Drive
  • Sherwood Forest
  • Sir Johns Homestead
  • Upper Parkland
  • Whiteoaks Lorne Park

Spray Method
The City has contracted Zimmer Air Services to implement the spray. Two applications will occur over a three-day period between the hours of 5 to 7:30 a.m. Two helicopters with a spray system will fly about 15 to 30 metres above the treetops. Spraying is weather dependent and will only be done under the right conditions.

Closures and Traffic Disruptions
The City will be implementing a traffic plan that requires temporary roads, parks and trails closures, including Rattray Marsh. The closures are necessary to meet approval requirements from Transport Canada.

Road closures are expected to last less than 30 minutes, between 5 to 7:30 a.m. All emergency services will have full access to all properties within the spray zones.

Preparing for the Aerial Spray
The City is committed to ensuring all possible steps are taken to keep Mississauga healthy and habitable for all residents. The safety and health of residents and the protection of the environment are top priorities. The public may hear helicopter noises during the early morning. All necessary safety precautions are taken to ensure minimal risk to the public, staff and the applicators.

  • Residents are unlikely to experience any health effects and no special precautions are necessary or required. Individuals who would like to avoid exposure during a spray program may wish to consider the following measures
  • Remain indoors during the spray and up to 30 minutes thereafter
  • Close doors and windows when the spraying is taking place
  • Bring in laundry, toys and pets indoors before spraying begins
  • Practice good personal and food hygiene (e.g. hand washing after outdoor activities, especially after gardening; leave outdoor shoes at the door; washing all fruits and vegetables before eating or cooking)
  • Cover lawn furniture, automobiles, outdoor tables, pools, BBQs, play equipment and sandboxes and/or rinse them – with water after spraying is finished
  • Leave heating units/air conditioners on, with vents set to the closed position, or selecting the recirculate function
  • Contact Peel Public Health or your family physician if you are concerned that a personal medical condition may be aggravated by the spraying

About the Spray
The City of Mississauga will be using a Bacillus thuringiensis subspecies kurstaki (Btk), registered under the trade name of Foray® 48B. Btk is a naturally occurring bacterium found in soil and is not a chemical. It has been successfully used by the City of Mississauga in 2006 and 2007 to control gypsy moth populations.

Once applied, Btk biodegrades quickly, in approximately one to four days, through exposure to sunlight and other microorganisms. There are no groundwater contamination concerns as Btk does not travel through the soil beyond 25 cm. Btk is specific only to caterpillars and does not have impacts to mammals, birds, fish, or other insects, including honey bees.

Residents with questions or concerns related to the health impacts of aerial spraying with Btk can call the Region of Peel Public Health at 905-799-7700 or speak to their family physician.

For up-to-date information about the aerial spray details such as road closures, spray dates, times and locations, call 3-1-1 or visit


Media Contact:
Karen Flores
Senior Communications Advisor
City of Mississauga
905-615-3200, ext. 5053
TTY: 905-896-5151