November 8, 2023 |
Photo – Musk Thistle, Thistle Crown Weevil, Thistle Head Weevil – Courtesy BugGuide.com
Carbon County Weed and Pest uses a variety of insects to combat invasive plant species.
The first documented invasive plant life appeared in the United Stated in the late 1700’s. Plants like Canada thistle and leafy spurge arrived aboard ships from Eurasia. They thrived. As the country expanded westward, so did the invasive plants.
Carbon County Weed and Pest District Supervisor Reese Irvine said leafy spurge was first discovered in Wyoming in the 1940’s. Irvine said his predecessor, Larry Justison, established a biocontrol program in Carbon County to fight against a different invasive plant, called musk thistle. Irvine said roughly 40 years ago, Carbon County Weed and Pest introduced two different weevil species around Encampment to prevent the musk thistle from overwhelming native plant life. Irvine said the weevils can no longer be bought from insect suppliers. However, the district supervisor said enough of the beetles are still in the area for Weed and Pest to continue using them to fight against the invasive thistle.
Irvine said Carbon County Weed and Pest uses weevils, flies, and different types of fungus to combat nine invasive plants in the area. The district supervisor said the non-native plants most likely came from Europe and Asia.
Irvine said the biocontrol insects are harvested from the homeland of the invasive plant species he is trying to fight. The weed and pest district supervisor said the weevils used around Encampment came from where the musk thistle originated, Eurasia.
Irvine said thistle-head and crown weevils are no longer available from insect suppliers because of their negative impacts on native plants species and the musk thistle. The weed and pest district supervisor said the weevils don’t appear to have been eating the native thistles in Carbon County. Because of their potential to harm native plants, Irvine said the government has made it difficult to introduce biocontrol insects into the environment.
Irvine said Carbon County Weed and Pest still uses biocontrol agents to combat invasive plant life. He said Assistant Supervisor J Sheehan oversees the biocontrol program in Carbon County. Irvine said Sheehan uses his two decades of experience to determine where the biocontrol agents can best be used.
Irvine said he hopes that new biocontrol agents to fight invasive white-top and hounds-tongue will be approved soon.
The weed and pest district supervisor said his department uses biocontrol agents in every part of Carbon County. Irvine thanked Assistant Supervisor Sheehan for running the program effectively.
In a written statement provided by Carbon County Weed and Pest, Sheehan, referring to the musk thistle eating weevils, said, “The very first biocontrol we started with is the most successful one. The insects were a perfect match for the climate and elevation in the area.”
Sheehan said the treatment not perfect, but it is manageable and controllable.
For tips to stop the spread of invasive species, visit wyoweed.org.
