Female gypsy moth laying eggs
Mississauga's Gypsy Moth Aerial Spray Program Completed

May 24, 2007

Mississauga’s Gypsy Moth aerial spray program, which began on May 18, was completed this morning. The final spray began at 5:15 a.m. this morning over area two, which included Sawmill Valley Trail, University of Toronto at Mississauga, Erindale Park and Credit Heights Woodlands.

Ten zones were included in the program and they were grouped into two areas. Each area received two sprays of the bacterial insecticide Bacillus thuringiensis subspecies kurstaki (Btk).

“During each spray, the Btk application rate was 4 litres per hectare which is approximately equivalent to one jug of windshield washer fluid spread over two football fields,” said Forestry Manager Gavin Longmuir. “A very minimal amount of Btk was used during the sprays.”

In order to conduct the aerial spraying, the City of Mississauga went through a lengthy approval process which included: enacting a ‘Nuisance By-law’; obtaining a Ministerial Exemption from Transport Canada; and receiving the green light from other regulatory agencies such as the Ministry of Transportation, the Ministry of the Environment, Peel Regional Police and the Ontario Provincial Police.

A total of 287 hectares were sprayed, which equals less than one per cent of Mississauga’s total land mass.

Preliminary surveys within the treatment areas are already demonstrating the Btk aerial sprays are having significant impact on Gypsy Moth caterpillar development and infestation populations.

For more information on Mississauga’s Gypsy Moth aerial spray program, please visit the Gypsy Moth website at or e-mail

Mississauga is Canada’s sixth largest city with a population of more than 700,000. With
well-established infrastructure and state of the art facilities, the City is considered to be an employer of choice, delivering quality municipal programs and services to its citizens. Mississauga is a dynamic, diverse, and progressive municipality, known for its economic strength and for being Canada’s safest city.


Media Contact:
Laurel Schut
Manager, Corporate Communications (A)
Phone: 905-615-3200 x5832
TTY:    905-896-5151

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