The non-agricultural use of permethrin in Canada as a mosquito treatment, and the implications to insect and spider biodiversity and the food chain

Petition: 473

Issue(s): Biological diversity; Compliance and enforcement; Human/environmental health; Pesticides; Toxic substances

Petitioner(s): A Canadian resident

Petitioner location(s): Toronto, Ontario

Date received: 6 December 2022

Status: Completed—Response(s) to petition

Summary: The petition raises concerns about the use of permethrin as a broad-spectrum insecticide to kill mosquitoes in southern Ontario’s cottage country and about how its application will inadvertently kill many non-target native insects and spiders; cause adverse health effects on local insect, mammal, and bird populations; and lead to biodiversity loss.

The petition claims that with the increasing popularity of permethrin-based mosquito control services, the effects of this pesticide are expanding. The petitioner notes that the number of mosquitoes observed near their cottage in central Ontario has dropped significantly over a period of 2 years. The petitioner questions whether it is Environment and Climate Change Canada’s or Health Canada’s policy to exterminate all mosquitoes and whether the impact on biodiversity of eliminating a primary consumer from the food chain has been researched. The petitioner asks whether the population levels of insectivore birds, bats, mammals, and amphibians in areas where permethrin is used extensively can be monitored to determine whether their numbers are affected.

The petition states that the permethrin label indicates that it is highly toxic to bees and predatory mites and that it should not be applied or allowed to drift to crops or weeds where bees are actively foraging. Despite this, the petitioner maintains that there was no wildflower avoidance while their neighbour’s property was being sprayed and that bees pollinated the flowers immediately after spraying. The petition questions whether the technician is allowed to do this given the product label and whether spraying can be done without applying a bee-killing permethrin to the flowers.

The petition states that permethrin has a half-life of 39.5 days and is applied every few weeks. The petition asks whether non-target insects living in treated properties will be able to complete their life cycles and survive if they are exposed to permethrin repeatedly over several months. The petition also maintains that permethrin can cause mammals’ and birds’ eyes to burn and questions the legality of spraying non-target species when they are hiding in foliage.

The petition refers to the Canadian Environmental Protection Act, 1999 and inquires whether the non-agricultural use of permethrin undermines Canada’s commitment to biodiversity protection as defined in the act. The petition also refers to the Species at Risk Act and asks whether spraying milkweed plants during monarch butterflies’ egg-laying season contravenes the act because monarchs are considered an endangered species.

The petition raises concerns about the use of permethrin in residential areas and about human residents’ persistent exposure to it. The petition refers to the Canadian Environmental Protection Act, 1999 and asks whether the precautionary principle can be applied to limit the non-agricultural use of permethrin for non-essential purposes.

The petition maintains that backpack foggers can disperse pesticides from 15 to 40 feet, which is significant for property owners with narrow residential properties, and asks whether the Pest Management Regulatory Agency will create guidelines for the use of backpack foggers in residential settings with narrow properties to respect the rights of Canadians who do not wish their land to be fogged.

Federal departments/organizations responsible for reply: Environment and Climate Change Canada; Health Canada