Invasive Plants
Invasive plants cause serious economic and environmental problems. They aggressively outcompete desirable vegetation which reduces range and crop productivity, recreational enjoyment and habitat value. Established infestations are difficult to control and often persist for many years, costing landowners time and money.
What is Biological Control?
Biological control (aka biocontrol) reunites invasive plants with their natural enemies, predominantly insects and plant diseases. The bioagents are host-specific and suppress invasive plant infestations to a more environmentally and economically acceptable level. Biocontrol will not eradicate infestations. It is most successful in areas with peripheral native plant communities that can re-claim the area once the invasive plants have been weakened by the bioagent.
Research performed before the release of these bioagents is extensive and includes testing of closely related native plants or plants of economic concern. New bioagents are only approved for release after determining their high host-specificity and lack of impact to other plant species of concern. Read more about the screening process here.
How Does Biocontrol Reduce the Impact of Invasive Plants?
- Weakens plants by destroying vital tissue
- Reduces plants’ competitive ability
- Decreases seed production
Successful biocontrol may be achieved with one agent. But generally, more than one agent is required, impacting different parts of the plant throughout its life cycle.
Is Your Property Suitable for Biocontrol?
Bioagents may already be present on your property. Look for stunted growth and damage to the leaves, stems, seed heads or roots of invasive plants.
If there are no signs of bioagents, your property may be suitable for a release. The following criteria must be met:
- Infestation size is over one acre
- There will be no other methods used to control the infestation, including pulling, mowing or chemical application
- There is no ongoing soil disturbance
- You are prepared for long term monitoring with support
- If the site meets release criteria, the landowner will work with OASISS staff and there is no cost
The Benefits
- Once established, insects will reproduce and move around on their own without the need for human intervention
The Downsides
- It can take a long time to notice a reduction in the infestation
- It may not be effective
- Bioagents are not available for every invasive plant species
Biocontrol is not an end point.
It is the starting point for shifting to an ecologically balanced, resilient plant community that relies on diverse, ongoing management.
Common Invasive Species with Bioagents in the Okanagan-Similkameen
Promising Biocontrol Currently Undergoing Screening
*NOT available in B.C.*
There are multiple biological control agents undergoing research and screening for some high priority invasive plants in the region. This includes tree of heaven, Russian olive, Himalayan balsam and hoary cress.
Tree of heaven
Click HERE to download biocontrol factsheet