Canada Thistle

This project was a 4-way partnership with Hardware Ranch (Division of Wildlife Resources), the US Forest Service, Utah State University, and Mount Logan Discovery to study and release Canada Thistle Stem Bore Weevils into the hay meadows at Hardware Ranch Wildlife Management Area in Blacksmith Fork Canyon--the goal is to limit the spread of non-native Canada thistle plants that are taking over the habitat.You can read the Herald Journal article on this project by clicking here.

You can view a photo album by clicking here.

Below, are some student writings about the project:

Canada Thistle   

                Imagine a summer hike in the mountains.  Shorts and hiking boots, then off to explore. Ouch! A patch of small purple blossomed thistle blocks your way. You have just walked into a patch of an invasive plant called Canada thistle. As much as it can ruin a pleasant summer hike, its impact on the natural environment is even more distressing.

                The name Canada thistle may lead you to think it is native to Canada, but it actually is a plant that traces its origins to the area of Greece and Turkey. Canada thistle is an invasive plant species that crowds out native plants. Cattle won’t eat the thistle and elk that do find that its prickly leaves disturb their digestive system.

                Canada thistle is difficult to control. The flower can produce up to 40 seeds per head. It can also reproduce from vegetative buds in its root system.

Biological Control

                In the war on weeds and invasive plant species, whether that war is being waged on a large or small scale, many think the only weapons in their arsenal are chemicals.    Biological control is an ancient method that is receiving modern scientific respect. Biological control, simply stated, is using natural, biological enemies to control the spread of weeds or insects.  Biological control, like other weed and insect control methods, is not without its concerns. Careful studies are conducted to ensure that insects, such as the Canada Thistle Stem Boring Weevil, do not become a new invasive species.

 Invasive Species

                Weeds. You notice them one day and a week later there are 30. These invasive species come from literally all over the world and compete for survival with the native species. Invasive species compete with the native species and change the natural flow of the food chain.

                Techniques are being tested and used to provide effective and environmentally friendly weed control. Invasive species can be plants, insect or other animals that take over the native species. In our yards, we pick the plants we like and label the invasive species as weeds. In nature, native plants have evolved to fit their niche. 

Canada Thistle Stem Boring Weevil

                A predator is being introduced into Northern Utah. A very tiny predator to be sure, but hopefully an effective predator. This predator is about a centimeter long. It is called the Canada thistle Stem Boring Weevil. Its name is deceptive though, it actually originates from the areas of Greece and Turkey. The Stem Bore Weevil is a natural predator for the invasive Canada thistle. For nearly 20 years closely monitored tests have shown the weevil can be safely introduced without becoming its own invasive species.  The female weevil legs its eggs on the leaf and stems and kills the thistle.

Links 

• • Carla Hoopes -

  • Intermedia Design 

  • Canada Thistle Control 

  • Canada Thistle 

    • • Noxious Weed Control Board 

        • Stem Weevil 

  • Maps

  • Google Map