The City of Toronto will implement the first round of its aerial spray program next week in several Toronto wards forecast to experience high populations of LDD (Lymantria dispar dispar) moth – at outbreak levels – in order to protect the tree canopy within those identified areas. A second aerial application is set to take place three to 10 days following the first application.
The LDD moth, formerly referred to as European Gypsy Moth, is an invasive, defoliating insect that feeds on a variety of tree species. Eradication of the LDD moth is not possible since it is well established throughout North America. The severe leaf loss created by these insects can make trees weak and susceptible to diseases and weather fluctuations. Untreated, those pressures can result in the loss of public and private trees.
During the aerial spray, three twin-engine helicopters with an ultra-low-volume spray system will fly between 15 and 30 metres above the tree canopy to apply biological, naturally occurring insecticides. The products must be applied directly to tree foliage, as LDD moth caterpillars must feed on the treated leaves for the insecticides to be effective.
Spraying is weather dependent and can only be initiated in the right conditions. As a result, specific spray dates are confirmed 48 hours in advance and can be cancelled if weather conditions change. Spraying will take place between 5 a.m. and 8:30 a.m. Residents within the affected spray zone are encouraged to check for and subscribe to e-updates on the City’s LLD moth webpage: www.toronto.ca/lddmoth, by calling 311 or following the City’s social media accounts.
No special precautions are required for residents in the spray zones, however, those wishing to avoid exposure can remain indoors during and immediately after the spraying. The insecticides that will be applied are not toxic to birds, humans, other mammals, adult moths, butterflies, bees and other insects and are approved by Health Canada for urban aerial use.
Several neighbourhoods in the following City Wards will receive aerial applications of Foray 48B (Btk) made from a naturally occurring bacterium found on dead or decaying matter in the soil: York Centre, Don Valley West, Don Valley East, Don Valley North, Willowdale, Beaches-East York, Scarborough Southwest, Scarborough Centre, Scarborough-Agincourt, Scarborough North, Scarborough-Guildwood and Scarborough-Rouge Park.
BoVir (LdMNPV) will be sprayed in Parkdale-High Park, specifically over High Park. BoVir is highly selective to LDD moth caterpillars and will be applied in High Park to avoid potentially impacting sensitive non-target moth and butterfly species unique to the park’s habitat.
LDD moth populations have been on the rise and moving into new areas of Toronto and other parts of Ontario. The City has used many interventions to manage LDD moths, including tree injections, egg mass removal and ground spraying. However, those methods alone will not effectively control or reduce the population in the identified high-risk areas.
More information about the City’s 2022 Aerial Spray Program, including the Public Notice of Pesticide Use, an interactive map and the subscription portal for e-updates is available at www.toronto.ca/lddmoth.
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