Trichosirocalus horridus

Plant species attacked: Bull thistle | Marsh plume thistle | Nodding thistle | Plumeless thistle
Biocontrol Agent Type: Rosette/root crown feeding beetle (weevil)
Country of Origin: The populations in BC originated in Germany
First Released in BC: 1991
Click on image to view larger photo: Trichosirocalus horrid adult
Positive monitoring and/or dispersal locations in BC on Nodding and Plumeless thistle:
(click image to view larger map)
Established Trichosirocalus horridus on Nodding thistle locations Established Trichosirocalus horridus on Plumeless thistle locations
This biocontrol agent is currently not available for distribution
View the in-depth Trichosirocalus horridus information page here