Forestry staff presented a corporate report recommending that the City of Mississauga consider an Aerial Spray Program in spring 2022 to help manage the Lymantria dispar dispar (LDD) moth (formerly known as gypsy moth) population. A budget of $3 million is being recommended as part of a wider pest management program to target LDD moths in affected areas of the city and protect Mississauga’s tree canopy.
LDD is a non-native and invasive pest that destroys trees by eating away at the leaves, which weakens trees and can lead to disease. In 2018, the City completed a similar Aerial Spray Program which helped slow the LDD population for approximately two years. However, the outbreak in Mississauga continues and within the last year, LDD populations have risen in many areas of the city as well as across southern Ontario.
“Protecting Mississauga’s tree canopy and the environment is more important than ever. Trees play such a critical role in helping fight climate change, especially in urban areas like Mississauga,” said Jodi Robillos, Commissioner, Community Services. “We need to ensure our trees, forests and greenspaces remain healthy today and into the future. An Aerial Spray Program will target public and privately-owned trees so that our neighbourhoods can continue to remain green and vibrant.”
This past spring, the City also treated 396 public trees in select parks and streets with TreeAzin injections and ground sprays of Bacillus thuringiensis subspecies kurstaki (BTK) to help control the LDD population.
LDD has been around Mississauga for many years. We cannot completely remove them, but we can take steps to reduce their population. The recommendation to conduct an aerial spray treatment will allow the City to cover larger targeted areas, including private property.
The aerial spray treatment will continue to use BTK – a bacterium that occurs naturally in soils and is produced specifically for pesticide use. According to Health Canada, there have been no identified public health problems or significant environmental concerns after years of widespread BTK use in forestry, agriculture and urban settings. BTK is only toxic in the caterpillar stage of the LDD life cycle and does not affect adult moths and butterflies, or other insects and wildlife.
