Submitted to: Government Publication/Report
Publication Type: Government Publication
Publication Acceptance Date: February 2, 2005
Publication Date: February 2, 2005
Citation: Smith, L., Drew, A.E. 2005. Biological control of spotted and diffuse knapweeds. USDA, Agricultural Research Service, Albany, California. 12 p. Technical Abstract: Spotted and diffuse knapweeds are invasive alien weeds that have infested over 11 million acres of rangeland in the western U.S. they cause an estimated annual loss of $14 million dollars in Montana alone. Thirteen species of insect biological control agents have been introduced, six of which are widely available. This booklet provides information to land managers to help them understand and use available biological control agents to control these two weeds, and to develop integrated weed management programs to achieve sustainable control. It describes how to identify these weeds and distinguish them from similar looking species. The biology and ecology of the weeds are reviewed, and basic management strategies are explained. Information on the identification, biology, distribution, use and effectiveness of available insect biological control agents is provided. Additional sources of information are listed.