May 15, 2017
City of Toronto to undertake aerial spraying in effort to control European Gypsy Moth population

The City of Toronto has determined a timeframe and locations for aerial spraying as part of its ongoing efforts to manage the European Gypsy Moth (Lymantria dispar) infestation.

The European Gypsy Moth is a defoliating insect that is considered a major pest in North America. The caterpillar, or larvae stage of the insect, eats the leaves of trees making the trees more susceptible to disease and damage from other insects or weather-related factors. The City of Toronto has and will continue to work with neighbouring municipalities and other levels of government to manage the European Gypsy Moth infestation.

City staff from the Urban Forestry unit of Parks, Forestry and Recreation use an Integrated Pest Management (IPM) approach in dealing with the forest pest issues in Toronto. Staff survey European Gypsy Moth egg mass numbers in high-risk areas every year. The surveys help determine outbreak threshold levels. The primary objective of the gypsy moth control program is to protect vulnerable trees from moderate to severe defoliation.

In west Toronto, the infestation levels have reached a point where mechanical control methods and ground spraying of pesticides on individual trees are no longer effective in controlling the European Gypsy Moth population. Aerial spraying of Foray 48B Biological Insecticide Aqueous Suspension containing the active ingredient Bacillus thuringiensis subspecies kurstaki (Btk) registered under the Pest Control Products Act (Registration Number: 24977) is now planned.

The spraying will take place from May 18 to June 10 in infested areas across the city. Spraying will occur from 5 to 7:30 a.m. each day. Areas that will be sprayed are:

• Princess Margaret Boulevard and Kipling Avenue
• Thorncrest Road
• Edenbridge Drive
• Edenbrook Hill
• Valecrest Drive
• North Drive
• Royal York Road and Bloor Street West
• The Kingsway
• Baby Point Crescent/Baby Point Road
• Jane Street and Bloor Street West

Spraying is dependent on weather and will only be done in the right conditions. As a result, specific spray dates are chosen 48 hours in advance, and can be cancelled if weather conditions change. Residents within the affected spray zones are encouraged to check for updates on the City's website at or by calling 311 (if calling from outside Toronto, 1-855-551-5150).
A two-engine helicopter with an ultra-low-volume spray system will fly about 15 to 30 metres above the tree tops and will spray Btk. Local road closures will be in effect during the aerial spraying to minimize any potential risks associated with the low-flying helicopter. Notification signs will be posted along local roads to announce the closures.

Btk does not affect adult moths and butterflies, other insects, honeybees, fish, birds or mammals. It kills young caterpillars that are present at the time of spray. Through aerial spraying, Btk will be applied to the foliage of the trees and the caterpillars must feed on the treated leaves for it to be effective.

The health and safety of residents and the health of the environment are top priorities for the City of Toronto. Health Canada affirms that the Btk pesticide is not linked to any significant health risks to humans from either direct or indirect (i.e. spraying) contact with the product. No special precautions are required for residents in the spray zone. However, if you wish to avoid exposure to Btk, remain indoors during and immediately after the spraying. Residents can also cover patio furniture or outdoor playing areas prior to the spraying or hose them off afterward.

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