Aerial spraying planned for Glen Stewart Ravine to control LDD Moths

Local residents and the City of Toronto are being called upon to do their part to help control the numbers of LDD Moths in the Beach area.

Valerie Edwards, who lives near Glen Stewart Ravine, said the moths are taking on enormous toll on oak and other trees in the community.

She said the situation is a “neighbourhood emergency” and the time to take action to stop the hatching of the moths is right now.

“Our oak trees are critical to how we define ourselves as a neighbourhood,” said Edwards.

She is urging local residents to check the trees on their properties for evidence of egg masses (which are usually an amber colour) and if they find them, to scrape them off and dispose of them in plastic bags in the trash. Simply knocking the egg masses off the trees onto the ground does not prevent them from hatching.

The LDD Moth is a non-native species that can wreak havoc on tree foliage. There are four phases to the moth’s life cycle: egg, caterpillar, cocoon and moth.

The egg phase is when residents can spot the clumps of eggs, hundreds or even thousands at a time, stuck to surfaces such as tree trunks but also on exterior walls of buildings and even on patio furniture.

In spring, as the weather gets warmer, the eggs hatch and the caterpillars begin their journey up the tree trunks to feast on leaves. This defoliates the trees and a critical time and puts them in danger of not surviving. On average, one caterpillar can consume one square metre of foliage.

Along with the egg clumps, residents can also be on the lookout for the caterpillars climbing up trees. They can be identified by distinctive red and blue dots that appear as they begin to moult. If spotted, residents are encouraged to pick them off the trees and dispose of them. Residents can also consider having trees on their properties treated to prevent infestations.

Another option is burlap banding which helps to stop the caterpillars from climbing up trees. Information on burlap banding can be found at https://www.toronto.ca/wp-content/uploads/2020/02/8b53-european-gypsy-moth-resident-make-burlap-caterpillar-trap.pdf

Also, to help control the LDD Moths, the city will be undertaking two rounds of aerial spraying in the Glen Stewart Ravine this spring.

“As we’ve learned in the past, it’s so important for us to take preventative action against the LDD Moth infestation that has been ravaging Southern Ontario the last few years,” said Beaches-East York Councillor Brad Bradford.

The city’s Forestry Health department will be planning the spraying for between May 16 and June 15. Residents in affected areas will be notified by the city 48 hours in advance.

The aerial sprays will be done by helicopter in times of calm winds and no precipitation.

The spraying will be using Foray 48B Biological insecticide Aqueous Suspension with the active ingredient Bacillus thuringiensis kurstaki (Btk). The city says “Btk poses minimal risk to human beings, and it has been used by the City of Toronto during other aerial sprays many times.”

However, residents wishing to avoid exposure during spraying are advised to stay indoors “during and after” the immediate spray time.

“To remove Btk off any outdoor surfaces, like patio furniture, you can wipe it off with a damp cloth and soap,” the city said.

For more info on the city’s plans for spraying locally, go to https://www.toronto.ca/services-payments/water-environment/trees/forest-management/threats-to-trees-insects/european-gypsy-moth/

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