A recent review and proposed phase-out of an insecticide has raised concerns at both the field and policy level
by Lyndsey Smith
It is not clear what the three-year phase out of neonicotinoid insecticide imidacloprid will look like exactly, but the implications of losing an entire class of crop protection product is a serious change, regardless.
The three-year phase out of imidacloprid was announced by Health Canada’s Pest Management Regulatory Agency (PMRA) in November, 2016, catching much of the agriculture industry by surprise (even the owner of the active ingredient received very short notice of the announcement). A 90-day comment period followed the announcement, plus an extension, and it is reported the government received over 40,000 submissions concerning the phase-out.
While the restriction of neonicotinoid (neonic for short) use in Ontario, for example, has centred on a threat to honeybees, this PMRA decision centres on the risk to aquatic invertebrates — a main food source for fish and birds.
Pulse Crop Implications
For pulse growers, imidacloprid is not the most widely used of the neonic class, however, both clothianidin and thiamethoxam, also neonicotinoids, are now also up for review. The larger issue, explains Glenda Clezy, Agronomy Specialist for theSaskatchewan Pulse Growers, is the potential of losing an entire class quickly, and without any currently registered alternatives in some cases.
“(Neonic products) Cruiser® and Stress Shield® are used in pulse production,” she says, but perhaps of more concern is there is only one registered seed treatment control option for pea leaf weevil, and it contains thiamethoxam.
There may be some foliar alternatives for some pests, Clezy says, but not always. What is more, foliar applications can be too late or less selective, and that shotgun approach to control can be a bad thing for biodiversity, she says. Pea leaf weevil also feeds on nitrogen-fixing nodules — poorly
controlled populations of the pest could impact total nitrogen fixing ability, potentially impacting soil health and commercial fertilizer use over a crop rotation cycle.
There can be larger implications as farmers lose crop protection options, she says, “Not only will they move to less selective foliar options, but they lose resistance management tools, too.”
Pesticide reviews are not new or even rare — they are actually built in to Canada’s regulatory framework — however this particular review has raised some serious concerns on both the agronomic, field-level implications, and also on the big-picture policy and regulation side.
Nevin Rosaasen, Policy and Program Specialist with Alberta Pulse Growers, has been heavily involved in the Canadian pulse industry’s submission to the PMRA’s consultation on the three-year phase out of imidacloprid.
Building off of the agronomic and farmlevel concerns, Rossasen says there are significant policy questions that need answers, as well. To that end, the pulse industry hired a risk assessment firm to evaluate the science and process used in the review and subsequent decision to phase out imidacloprid. That review resulted in 12 specific questions, clarifications, or asks of PMRA — ranging from how farmers are to mitigate risks of non-selective foliar alternative products, to challenging the actual scientific proxies and evaluations used in the review.
Rossasen explains that in the absence of actual Western Canadian surveillance data, PMRA used other sources as proxy. What is more, much of the risk modelling was based on Eastern Canadian climatic conditions and crop systems, such as horticulture.
“The pulse industry strongly supports the mandate to protect the environment and our food system,” he says. “It is clear we need to stay focused on real risk, good data, and have sufficient time to review and consult on reviews.”
Perhaps most importantly, Rossasen says that agriculture as an industry wants to be proactive and take a much bigger picture approach to water quality monitoring, for example, than what has been done to date. There is a push to create a water quality monitoring body on a national level, so that
instead of trying to find data when a review is called, there would be ongoing monitoring that could flag a problem early.
The final decision on the imidicloprid phase-out will be released January 1, 2018.
The Neonic Review
Health Canada’s Pest Management Regulatory Agency (PMRA) regularly re-evaluates registered pesticides to determine whether the use of products containing these pesticides continues to be acceptable according to current standards. The Pest Control Products Act requires pesticides to be reviewed every 15 years as a minimum. A re-evaluation of imidacloprid was initiated in 2009. The review was not triggered by any particular concern; however, an increase in reported bee incidents in 2012 triggered a more detailed investigation into imidacloprid on the potential harm to bees and other pollinators.
In November 2016, Health Canada published a Proposed Reevaluation Decision for imidacloprid. The consultation period closed on March 23, 2017. The re-evaluation, which included a thorough assessment of potential health and environmental risks from imidacloprid exposure, did not identify any human health concerns when used according to updated label directions. However, the environmental assessment of imidacloprid identified risks to aquatic insects, such as midges and mayflies, which are important food sources for fish, birds, and other animals.
Based on the assessment’s findings, Health Canada is concerned that the current use of imidacloprid pesticides in Canadian agriculture has resulted in environmental levels that are not sustainable, and is therefore proposing risk management actions to protect the environment. Health Canada’s proposed risk management plan includes transitioning the agriculture industry away from using imidacloprid within three years, for most products. In some cases, where there are no alternative pest control products available, a longer phase-out period of five years is being proposed to allow for the development of new alternatives.
— Source: Health Canada