Blog: The Wheat Sheaf

Proposed Re-evaluation Decision PRV2018-13, Strychnine and its Associated End-use Products for Control of Ground Squirrels

To whom it may concern,

Team Alberta, on behalf of Alberta’s crop sector, is concerned by the proposed re-evaluation decision of the Pest Management Regulatory Agency (PMRA) for the complete cancellation of strychnine for use in end-use products, such as Maxim 2% Liquid Strychnine Concentrate (LSC) and S.A.R.M Gopher Poison R.T.U, for the control of ground squirrels.

Team Alberta is a collaboration between Alberta Barley, Alberta Canola, Alberta Pulse Growers and the Alberta Wheat Commission. Collectively, we represent over 20,000 farmers, 20 million crop acres and over $5B in commodity exports from Alberta. Alberta crop sector farmers, along with our colleagues in Saskatchewan, are amongst those who would be most impacted by the proposed decision to remove this important pest control tool.

Richardson’s Ground Squirrels (RGS) are a declared nuisance throughout Alberta as per Schedule 1 of Alberta’s Pest and Nuisance Control Regulation. Population can fluctuate in size, but are persistent. while fluctuating, persist. An average sized population (12 squirrels/ha) can consume close to 90 lbs. of crop or forage grasses per acre in a month, resulting in substantial economic losses to farmers. Burrowing can cause significant yield damage to crops, with burrow opening densities can range from 142 to 163/ha. RGS also compete with grazing farm animals in forage grasses, can cause significant economic losses in equipment damage, and cause water loss in irrigated fields. While the impacts of RGS are prevalent among all field types, canola, as a preferred food source of RGS, is particularly affected. Severe crop loss in canola can easily exceed 20% in a few days. Wheat, barley and other cereals are impacted with crop damage and yield losses, and pulse crops are further impacted by the dirt piles that are created which affect harvesting. Destruction of hayfields by RGS can downgrade the export quality of hay which impacts the price that farmers receive. RGS burrows and mounds can often make harvesting hay fields impossible.

When an infestation occurs, it is often wide-spread and can go underestimated until the crop emerges and RGS arise from the burrow to feed on seedlings. When RGS are detected at this time, farmers need tools that allow them to take swift and effectual action to avoid what could be hundreds of thousands of dollars’ worth of crop damage. Farmers are aware of and are using other chemicals (e.g. Rozol) and physical (e.g. shooting) control alternatives as part their pest management approach to controlling RGS, however, in the case of a severe outbreak, there currently is no safe or practical alternative to the label use of LSC to quickly gain control of RGS and avoid crop damage as the plant emerges.

This can be demonstrated by the fact that the PMRA has cancelled the registration of LSC for use in ground squirrels on at least two previous occasions in the past, only to subsequently impose emergency registrations to respond to significant population explosions causing decimation of crops across the Prairies. It should be noted that during these cancellation periods, ready-to-use bait systems with 0.4% concentrate, still remained available to farmers although they were ineffective in getting infestations under control.

At the time of emergency registration of LSC the PMRA, together with the provinces and producers, committed to finding a viable solution to the problem of RGS control. Work was underway to develop a longterm, Integrated Pest Management Strategy (IPMS) that would include rodenticides, along with other nonchemical controls, to keep infestations below the economic threshold levels. This included a commitment to conducting an evaluation of the effectiveness of the various toxins and management strategies. An additional study to look at the economic impacts of RGS was also committed to. Team Alberta is not aware of these actions having been completed. It is noted in the proposed decision that certain integrated pest management (IPM) practices have not been adopted due to a lack of effectiveness or practicality (e.g. maintenance of vegetation greater than 15 cm). Further, it was stated that there an “absence of evidence to support that IPM strategies and mitigation methods added since the last evaluation are effective”. As such, Team Alberta would recommend that IPM practices be studied, and a viable IPMS be developed, prior to a final decision being taken. Cancellation of LSC is not a long-term strategy for sustainable control of RGS in the Prairies.

Alberta farmers are stewards of the land and are committed to mitigating any risk associated with their operations that could impact humans, animals or the environment. When risk is identified by the PMRA and decisions are proposed that implicate farmers' practices and livelihood, the risk must be demonstrated through scientifically rigorous and sound methods. Team Alberta has concerns regarding the studies and evidence used to arrive at PMRA’s proposed-decision regarding LSC. We are concerned with the timing and the peer-review process undertaken in the studies referenced in the Proposed Re-evaluation Decision. Further, it was stated that no relevant, public scientific literature was found related to strychnine and nontarget species, which we know to be false. As such Team Alberta advocates for the need of this proposed re-evaluation decision to be reconsidered taking into account the quality and availability of scientifically derived research.

As part of a re-consideration of the decision, Team Alberta would recommend that PMRA evaluate the effectiveness and safety of the various alternatives indicated in the proposed decision. For example, chlorophacinone and diphacinone (multi-feed anticoagulant baits – e.g. Rozol) can be effective in the early spring when feeding choices are limited. On their own, however, they can become less than 30% effective after green growth appears in the spring. Further, research suggests that multi-feed anticoagulants can be as or more dangerous on non-target species due to their multi-feed attributes that allows for continued mobility for up to three feeds. Fumigant controls such as aluminum phosphide (e.g. Phostotoxin) are highly restricted products which represent significant health risks to applicants. Farmers not only prefer LCS, there is no other effective or safer alternative currently available to control severe outbreaks when LCS is used according to the label.

It should also be noted that RGS are a non-migratory, native species to North America and their geographic distribution is limited to the northern plains and foothills. Their habitat preference is limited to brown soil zones on elevated microhabitats. Within an international context, consideration of regulatory decisions made by our OECD counterparts, in relation to LSC must take into account the existence and/or prevalence of RGS in those jurisdictions.

In Alberta, LSC is currently being distributed in a controlled environment under the authority of counties. Trained Agricultural Fieldmen assess the severity of the outbreak, provide the appropriate training and apply the necessary protocols prior to distribution to qualified farmers. Team Alberta maintains that there are alternate approaches that should be considered prior to proposing a complete cancellation of these products. Opportunities exist to build on the existing provincial distribution model to: enhance controls, provide formal training, limit usage to severely affected regions, and/or make amendments to the product labels to return to more comprehensive guidelines.

Team Alberta farmer members, directors and staff would be pleased to work together with our provincial government and the PMRA to develop a viable integrated pest management strategy for the control of RGS on the prairies, which includes the retention of LSC as a tool for emergency use, until an effective, alternative product becomes available. We thank you for your consideration.


Jason Lenz, Alberta Barley Chair 
Renn Breitkreuz, Alberta Canola Chair 
D’arcy Hilgartner, Alberta Pulse Growers Chair 
Kevin Bender, Alberta Wheat Commission Chair 


Executive Director, Pest Management Regulatory Agency - Richard Aucoin
Minister of Health – Hon. Ginette Petipas Taylor
Minister of Agriculture and Agri-Food Canada – Hon. Lawrence MacAulay
Minister of Agriculture and Forestry Alberta – Hon. Oneil Carlier
MP Randy Boissonnault – Edmonton Centre

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