Mississauga plans spring 2022 aerial spray program – City of Mississauga

Today, during the budget committee, forestry staff presented a business report recommend that the City of Mississauga consider an aerial spraying program in the spring of 2022 to help manage the Lymantria dispar dispar gypsy moth population (LDD) (formerly known as gypsy moth). A budget of $ 3 million is recommended as part of a larger pest control program to target moths in affected areas of the city and protect Mississauga’s tree canopy.

LDD is a non-native, invasive pest that destroys trees by gnawing on leaves, weakening trees and can lead to disease. In 2018, the City completed a similar aerial spraying program that helped slow the LDD population for about two years. However, the outbreak in Mississauga continues and over the past year LDD populations have increased in many areas of the city as well as in southern Ontario.

“Protecting Mississauga’s canopy and environment is more important than ever. Trees play a vital role in the fight against climate change, especially in urban areas like Mississauga, ”said Jodi Robillos, Commissioner, Community Services. “We need to make sure that our trees, forests and green spaces stay healthy today and into the future. An aerial spraying program will target public and private trees so our neighborhoods can continue to stay green and vibrant. “

Earlier this fall, the City hired consultants Lallemand Inc./BioForest – experts in data collection analysis and operational advice on aerial spray programs. As consultants, they monitored and studied LDD egg masses in 50 parks and 75 other areas of the city. Egg mass surveys help determine which areas of the city have higher populations of LDD and are at risk of severe tree defoliation.

“This year, Mississauga has seen high levels of LDD population and forestry staff have worked quickly to identify areas of the city most at risk. The data we received helped us predict the extent of defoliation that may occur in 2022 when LDD caterpillars emerge in the spring, ”said Stefan Szczepanski, Acting Director, Parks, Forestry and Environment. “The results showed that 64% of the parks studied will experience severe defoliation due to a large and healthy LDD population. “

Last spring, the City also treated 396 public trees in some parks and streets with injections of TreeAzin and ground sprays of Bacillus thuringiensis subspecies kurstaki (BTK) to help control the LDD population.

Szczepanski added, “LDD has been in Mississauga for many years. We cannot eliminate them completely, but we can take steps to reduce their population. The recommendation for an aerial spray treatment will allow the City to cover larger target areas, including private property.

The aerial spray treatment will continue to use BTK, a bacteria naturally present in soils and produced specifically for the use of pesticides. According to Health Canada, no significant public health issues or environmental concerns have been identified after years of widespread use of BTK in forestry, agriculture and urban settings. BTK is only toxic at the caterpillar stage of the LDD life cycle and does not affect adult moths and butterflies, or other insects and wildlife.

The report of a recommended aerial spraying program for 2022 will be submitted to Council on December 8, 2021 for final approval.

For more information on the recommendation, including identified neighborhoods and parks where aerial spray treatment would take place, read the business report.

2018 Aerial Spray Treatment in Mississauga [Download high-resolution photo]


Information for owners

As the City has now completed its egg mass investigation, residents can help control the Lymantria dispar dispar population and protect their own trees by searching their property for egg masses and removing them. Egg masses can be found not only on trees, but also on window sills, under eaves, around birdhouses, on patio furniture, and on fences or mailboxes. Removal of the egg mass can now be done until the end of April.

For more information on how to identify and eliminate egg masses, click here.

Watch the video on how to identify and remove an egg mass: youtu.be/zLL3SQmv2sM

Residents can also report sightings of Lymantria dispar dispar in their neighborhood using a online declaration form.

LDD egg mass on a tree
LDD egg mass [Download high-resolution photo]

On Lymantria dispar dispar

Lymantria dispar dispar – formerly known as gypsy moth – has been established in Ontario for over 30 years. The species is native to Europe and has been introduced to North America. Lymantria dispar dispar the caterpillars eat the leaves of trees in spring and early summer. They strip the leaves until early summer when they enter their moth stage. They prefer oaks but will eat the leaves of any hardwood tree such as ash, birch, or elm.

Healthy trees can regrow their leaves in the same season, but a Lymantria dispar dispar infestation weakens trees and can make them more susceptible to damage from other insects and diseases.

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Media contact:
City of Mississauga Media Relations
[email protected]
905-615-3200, ext. 5232
TTY: 905-896-5151

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