City Council approves aerial spray program to address Gypsy Moth infestation in Hamilton

Hamilton City Council approved a vendor for the aerial spray program that will address a significant Gypsy Moth infestation in parts of Hamilton. Beginning in late May to early June 2018, a bio-pesticide will be applied to properties in West Hamilton, Ancaster, Dundas and Flamborough to manage the infestation, as was done successfully in 2008.

The bio-pesticide is an organic product that specifically targets Gypsy Moths at their caterpillar stage and other caterpillars, but will have no health impact on humans, and will not affect pets, other animals or bees.

City of Hamilton Forestry crews have been monitoring Gypsy Moth populations over recent years. In the fall of 2017, staff recorded population levels that require control. The aerial spray program will reduce the Gypsy Moth populations in Hamilton, and will not entirely eradicate the pest.

Neighbouring municipalities of Burlington, Oakville, Mississauga, and Toronto are also beginning their own programs.

The exact dates and time for the aerial spray are weather dependent, the City will share up to date details on, social media, through the City’s new mobile app, CityApp.

Quick Facts:

  • In 2008, Council approved a by-law that directs control programs be implemented if populations of Gypsy Moth are above an identified treatment threshold. Monitoring completed in 2016 and 2017 noted high populations of Gypsy Moth, which exceed this threshold.
  • The Gypsy Moth is an invasive pest that was introduced accidentally to the United States, from Europe in 1869. Since then, the Gypsy Moth has expanded its range over much of the eastern United States and Canada. It was first detected in Ontario in 1969 and quickly spread across southern Ontario. It is now well established throughout southern Ontario and as far north as Sault Ste. Marie.
  • Gypsy moth larvae or caterpillars will feed on tree leaves. If the larvae population is too high, they will defoliate entire tree canopies and forests in a short amount of time.
  • Repeated consecutive defoliation of trees of three years or more has the potential to kill trees and leave long-term negative impacts to the urban forest.