Knapweed Biocontrol Workshop on August 9, 2006

One of the most common questions we receive at the Central Kootenay Invasive Plant Committee is “How do I get rid of knapweed?”

Spotted knapweed is the most prevalent non-native invasive plant species in the Central Kootenay. It covers thousands of hectares of land in BC, is highly competitive and degrades natural plant communities. The knapweed invasion has a negative effect on wildlife, including important ungulate winter range. An individual plant can produce up to 140,000 seeds per square meter, giving little opportunity for native plants to grow. Around the world, invasive species are considered the second largest contributor to the loss of biodiversity (e.g. extinction of species), next to the loss of habitat.

There are many methods for controlling knapweed including biological control (biocontrol). This method involves the use of the plants natural enemies, usually insects, that attack and weaken the plants. These insects are carefully screened by Agriculture Canada to ensure that they only attack knapweed and no other plant species. There are several insects that have been used to help control knapweed including root-attacking moths and weevils, and seedhead-attacking weevils and flies.

Another common question that we get asked is “How do I get some of those insects for my property?!”

Our answer? You probably already have most of them!

Biocontrol agents have been released in the West Kootenay area since the 1950’s. The Ministry of Forests has been actively releasing biocontrol agents for knapweed since the 1970’s in this area. In this region, there have been so many biocontrol releases for knapweed that the insects have likely spread onto your property already, giving you a helping hand for knapweed control.

Join the Central Kootenay Invasive Plant Committee on Wednesday, August 9, at 7pm a the Passmore Senior’s Centre to learn more about knapweed biocontrol. There will be an indoor presentation to learn more about biocontrol, and then we’ll head outside to have a look at these insects up close. You’ll learn how to monitor your own property for insects that might already be there, and how to develop a strategy for controlling knapweed on your property.

Added on July 31st, 2006 - Return to Special Features