By Kelsey Johnson
The federal government’s pesticide regulator says certain uses of a popular insecticide need to be restricted in order to protect the health of pollinators.
In its final decision, published last Thursday, Health Canada’s Pest Management Regulatory Agency said certain uses of three neonicotinoid pesticides — clothianidin, imidacloprid and thiamethoxam — will be phased out over the next two to three years, depending if alternative products are available.
“The scientific assessments show varying effects on bees and other pollinators from exposure to each of these pesticides. To protect bees and other pollinators,” the agency said in a release, “Health Canada has announced that it will be cancelling some uses of these pesticides, and changing other conditions of use such as restricting the timing of application.”
Neonicotinoids are a popular class of nicotine-based pesticides widely used by the agriculture industry as a foliar spray (applied above ground), as a soil application (sprayed on the soil) and as a seed treatment (where the seed is coated with the pesticide before being planted in the ground).
The pesticides have faced public scrutiny in recent years because of concerns over whether they pose a threat to pollinators and aquatic insects. In August 2018, PMRA recommended the use of clothianidin and thiamethoxam be phased out over three to five years, once the ban was approved, because of concerns the pesticide poses a threat to midges and mayflies — a key source of food for fish. A final decision on aquatic insects is expected in January 2020.
In a technical briefing Scott Kirby, director general for the PMRA’s environmental assessment directorate, told reporters the restrictions and cancellations do not apply to seed treatments for cereal crops, including canola seed, although there are new labelling requirements.
However certain types of soil and foliar applications, particularly in relation to horticulture crops, will be banned or see restrictions imposed around time of use.
In its report, Health Canada said it is restricting the use of foliar applications of clothianidin for orchard trees, strawberries, and municipal, industrial and residential turf sites. Foliar applications for cucurbit vegetables — like squash, cucumbers, pumpkins — have been limited to one application per year.
There are also changes affecting how farmers can use imidacloprid. PMRA said last Thursday the agency is banning the use of the pesticide as it applies to foliar applications for crops including pome fruit, stone fruit, certain tree nuts with high pollinator attractiveness, lavender and rosemary.
The agency has also banned soil applications on legume, fruiting and cucurbit vegetables when grown outdoors, herbs harvested after bloom, small fruit and berries (including caneberry, bushberry, low-growing berry, berry and small fruit vine excluding grapes), and ornamental crops that are attractive to pollinators and planted outside.
Fruiting vegetables include crops like tomatoes, eggplants and peppers. PMRA has also determined certain flowering crops should not be sprayed before or during bloom, while others should see use restricted only when the crop is in bloom.
Similar changes have been announced around the use of thiamethoxam. Foliar and soil applications have been banned for ornamental crops that are planted outdoors and are attractive to bees and other pollinators. Foliar applications to orchard trees and soil applications for berry crops, cucurbit crops and fruiting vegetables should also be banned.
Health Canada said foliar applications for legume and outdoor fruiting vegetables and the majority of berry crops cannot be sprayed before or during bloom, while sweet potato and potato crops cannot be sprayed during bloom. Growers of woody berries, like blueberries, will be able to apply the insecticide the year before they cut their plants back.
PMRA has been reviewing the use of neonicotinoids since 2012. Kirby said the final decision on pollinators comes after new information was submitted to the agency. Asked whether that data would be used in the ongoing aquatic insect elevation, Kirby said most of the data supplied was specific to pollinators — although some material could be used in both re-evaluations.