University of Georgia. Center for Invasive Species and Ecosystem Health.

Provides state, county, point and GIS data. Maps can be downloaded and shared.

USDA. FS. Southwestern Region.

See also: Weed Field Guides for more species

University of Georgia. Center for Invasive Species and Ecosystem Health.

North American Invasive Species Management Association.

The NAISMA Classical Biocontrol Committee is excited to announce new peer-reviewed weed biocontrol publications for use by managers and landowners. Subject matter experts are developing a series of factsheets that cover invasive plants and their associated biological control agents in North America. Funding for these factsheets is provided by the United State Forest Service. NAISMA is partnering with iBiocontrol.org to host these publications.
See also: Resources on Biocontrol and Classical Weed Biocontrol Factsheets Released for Landowners and Weed Managers (Press Release - Aug 31, 2022)

USDA. APHIS. Cooperative Agricultural Pest Survey. National Agricultural Pest Information System.

USDA. NRCS. National Plant Data Center.

CAB International. Invasives Blog.

Russian knapweed (Rhaponticum repens) is a nonnative weed in the western United States. It was introduced in the late 1800’s and is now invading and degrading cropland, rangeland, riparian areas, and roadsides. This deep-rooted perennial is persistent and difficult and expensive to control by conventional means, is toxic to horses and outcompetes native vegetation by producing chemicals that inhibit plant growth. Russian knapweed is listed by the State of Colorado as a noxious weed, to be suppressed, contained, or locally extirpated.

The Colorado Department of Agriculture (CDA) offers biocontrol agents to help suppress weeds and insect pests. When two gall-forming agents were developed and tested by CABI, and became available for use against Russian knapweed, the CDA was prepared to use them against the more than 50,000 hectares of the weed that currently infests Colorado.