RMD-13-04: Consolidated Pest Risk Management Document for pest plants regulated by Canada
Appendix 13B: Risk Management Considerations for Senecio madagascariensis (Madacascar ragwort)

• Values at Risk
• Pathways of Introduction

Values at Risk

Canadian Livestock Industry

Senecio madagascariensis contains pyrrolizidine alkaloids that are toxic to livestock (i.e., cattle, sheep, goats, and horses) and causes irreversible liver damage. Total pasture land in BC was approximately 3.4 million acres in 1996 (Statistics Canada 1996), however the majority of farms producing cattle in BC are outside of the potential distribution range (i.e., coastal British Columbia and Vancouver Island) of the weed.

Animal Health

It contains pyrrolizidine alkaloids that are toxic to livestock (i.e., cattle, sheep, goats, and horses) and causes irreversible liver damage.

Biological Diversity

It can have a negative effect on biodiversity by competing with native vegetation such as grass and other low-growing plants.

Pathways of Introduction

Natural Dispersal

The risk of introduction into Canada by natural dispersal is low as there are no known populations near the Canadian border.

Intentional Introduction

No intentional introduction pathways were identified.

Non-intentional Introduction

1. Field crops not intended for propagation: The level of risk associated with the import of cereal grain into Canada is very low since imports originate primarily from areas where Senecio madagascariensis is absent.
2. Hay and Straw: The level of risk associated with imports of grass and forage seed into Canada is low since they originate primarily from areas where Senecio madagascariensis is absent.
3. Travellers and Their Effects: A considerable number of people cross the Canadian border every year. Approximately 5.4 million Canadians traveled abroad in the 4^th quarter of 2008 alone (Statistics Canada 2009). There is a high frequency of travel between Canada and areas where Senecio madagascariensis is present (Hawaii, Australia, Japan, Colombia, Argentina and southern Africa). This pathway is considered the most likely pathway of introduction of Senecio madagascariensis into Canada, but the level of risk is unknown.

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