Gopher Control

Res #: 24-04M
Number: 24
Year: 2004
Midterm: Yes
Expired: Yes
Responses Received: No
Departments: Health Canada

Resolution No. 24-04M

WHEREAS, the gopher population has been increasing in the past several years due to ineffective gopher control products; and

WHEREAS, the liquid strychnine of the past was most effective;

THEREFORE BE IT RESOLVED, that SARM continue to lobby to have this product reintroduced.

Response from Health Canada:

Although there are several chemicals used in products currently registered in Canada to control ground squirrels (for example, products containing diphacinone, chlorophacinone, zinc phosphide), at this time, those containing strychnine are considered to be the most effective. Before 1993, strychnine was available in a two percent liquid concentrate form for the control of ground squirrels. Users were required to mix and dilute the concentrate before use. Liquid strychnine has a very high acute toxicity.

After consultation with the Western provinces in 1993, the federal government took regulatory action to remove liquid strychnine concentrate from the market because of a number of non-target poisonings occurred. As a result, strychnine use for gopher control was restricted to ready-to-use (RTU) strychnine bait formulations. After this regulatory action was taken, users began to voice concerns that the available RTU baits were not as effective as the baits that were previously available.

Research conducted by Alberta Agriculture, Food and Rural Development confirmed that freshly prepared strychnine bait is more acceptable to ground squirrels because of its freshness and moistness, and consequently it is more effective. Wilson Richardson's Ground Squirrel (RGS) Strychnine Bait (manufactured by Maxim Chemical International Ltd. of Regina, Saskatchewan), and Fairview Gopher Cop R.T.U.W., (by Nu-Gro Corporation of Brantford, Ontario), are moist strychnine baits registered in 2004, and are comparable in freshness to the bait that could be made before 1993 using the two percent strychnine concentrate products.

These recently registered RTU bait products are considered to be fresh because they must be kept refrigerated immediately after manufacture and during shipping, and are to be used within a week from the date of manufacture for optimal results. Provincial extension specialists indicated that these products are very effective. If your municipality is interested in either of these products, please contact the manufacturers directly.

Health Canada's Pest Management Regulatory Agency, in conjunction with the Western provinces, has been facilitating an Integrated Pest Management program to address the Richardson's ground squirrel problem since 2003. Stakeholders participating in this effort include representatives from all levels of government, non-government organizations, producers, and industry.

Part of the objective of this program is to promote the use of alternatives to strychnine, including non-chemical methods of control and the use of registered pest control products containing active ingredients other than strychnine.