News release

Aerial Spray Program Begins in Mississauga

Environment | May 12, 2022

*This release has been translated into other languages.

The City of Mississauga is conducting an aerial spray tentatively scheduled to start on May 15 and end June 12, 2022. The spray will happen between 5 and 7:30 a.m. The spray will target and manage Lymantria dispar dispar (LDD), formerly known as “gypsy moth,” in affected city neighbourhoods. The timing of the spray is dependent on weather conditions, the emergence of LDD caterpillars and development of leaves on trees. Private and public lands in specific areas of Wards 1, 2, 3, 5, 6, 7, 8, 9, 10 and 11 will be sprayed.

The City has contracted Zimmer Air Services to implement the spray. Two helicopters with a spray system will fly approximately 15 to 30 metres above the treetops. Spraying is weather dependent and will only be done under the right conditions. Each area will be sprayed twice, with the applications being approximately seven to 10 days apart.

The City has drafted detailed FAQs to address specific questions regarding the spray that you may have or you can watch the public meeting from April 20 to learn more.

Specific spray dates are chosen 48 hours in advance and they can be cancelled up to 12 hours in advance based on weather conditions. The City will issue notice to the public 48 hours before each treatment, listed on the aerial spray website and provide up-to-date information at, on social media @citymississauga and @saugaparksrec. Residents are also encouraged to sign-up for aerial spray news alerts.

Spray Locations
To find out if your home is in the spray area, view the online Aerial Spray Treatment map.

Neighbourhoods Being Sprayed
Central Erin Mills
Clarkson-Lorne Park
Cooksville West
East Credit
Erin Mills
Gordon Woods
Meadowvale Village
South Common
University of Toronto Mississauga (UTM)

Parks and Woodlands Being Sprayed
(outside of the listed neighbourhoods)
Britannia Woods Community Forest
Dr. Martin L. Dobkin Community Park
Eden Woods
Hyde’s Mill Hollow
Jaycee Park
Marco Muzzo Sr. Memorial Park
Meadowvale Conservation Area
Paul Coffey Park
Pinecliff Park
Riverview Park
Sparling Woods
Staghorn Woods
Windrush Woods

About the Aerial Spray
The aerial spray will use a biological insecticide, Foray 48B Biological Insecticide​, Aqueous Suspension, containing the active ingredient Bacillus thuringiensis subspecies kurstaki (Btk) strain ABTS-351 Registration #24977 under the Pest Control Product Act. According to Health Canada, Btk treatment is considered low-risk to human health and the environment. Btk is only toxic in the caterpillar stage of the LDD life cycle and does not affect adult moths or butterflies.

View the City’s public notice of pesticide.

The most efficient way to treat widespread LDD populations is to apply Btk from the air. While the aerial spray will not eradicate LDD, it will reduce populations to more manageable levels. The spray will target the tops of trees.

Preparing for the Day of 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 in the early morning. All necessary safety precautions are taken to ensure minimal risk to the public, staff and applicators.

Peel Public Health recommends that residents stay indoors during the spray and for ​30 minutes following the spray to allow the droplets to settle.

Before the spray, residents should:

  • close windows
  • turn off fans and air conditioners, or select the recirculate setting
  • bring in laundry and toys
  • cover all vegetable and herb gardens
  • keep pets indoors
  • cover pools, BBQs, play equipment, lawn furniture and automobiles

After the spray, residents should:

  • wash/rinse pool covers, BBQs, play equipment, lawn furniture and automobiles with water
  • practice good personal and food hygiene (e.g. hand washing after outdoor activities, especially after gardening; leave outdoor shoes at the door; wash all fruits and vegetables before eating or cooking)
  • wash pets’ paws before entering the home

Residents with any concerns or questions about health and the use of Btk, can call Peel Public Health at 905-799-7700. Residents can also speak to their doctor.

Closures and Traffic Disruptions

The City will be implementing a traffic plan that requires temporary roads, parks and trail closures. The closures are necessary to meet approval requirements from Transport Canada. Vehicles with flashing lights and signage will also be used to alert traffic to the helicopter activity during the spray.

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

For questions or for up-to-date information about what you can do to control LDD on your property, aerial spray details such as spray dates, times and locations call 311 (905-615-4311 if outside City of Mississauga limits) or visit



Media Contact:
City of Mississauga Media Relations
905-615-3200, ext. 5232
TTY: 905-896-5151