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Biological Control Program

Biological control agents are organisms such as insects, nematodes, fungi or viruses that can be used to control and reduce weed populations. They are natural enemies of the target weeds, usually originating from Europe and Asia.

The use of insects for weed control is the most common type of biological control used in the TNRD. Biological control is suitable for large, dense infestations where other management strategies are neither cost-effective nor environmentally desirable. A good example of such an area in the Thompson-Nicola Region would be knapweed infestations on steep slopes covering a large area of grasslands. Biological control is also commonly used on sensitive sites, near water, on steep slopes or sites that have gravelly soil conditions. The insects weaken the plant’s seed production by feeding on the seed heads, or by eating or inhabiting other parts of the plant (i.e. root systems). Biological control typically takes a few years to see the results and will usually not totally eliminate the weed problem. Biological control insects will slow or stop the further spread of weeds and give native plant populations an edge to begin to re-populate an area.

The TNRD has partnered with the Southern Interior Weed Management Committee (SIWMC) to offer biological control agents to private landowners, free of charge. Biological control is one strategy that is used to combat the spread of some invasive plant species.

Insects are available for the following invasive plants:

• Spotted knapweed
• Diffuse knapweed
• Dalmation toadflax
• Hound’s tongue
• Leafy spurge
• St. John’s wort
• Thistles (selected species)

Availability of insects varies throughout the season. Please contact SIWMC for more information.

Southern Interior Weed Management Committee (SIWMC)
162 Oriole Rd.
Kamloops, BC V2C 4N7
Email: info@siwmc.ca
Website: www.siwmc.ca
Phone: (250) 851-1699