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United States Department of Agriculture

Agricultural Research Service

Research Project: Biological Control of Invasive Terrestrial and Riparian Weeds in the Far Western U.S. Region, with Emphasis on Thistles, Brooms and Cape-ivy

Location: Exotic and Invasive Weeds Research

Title: Status of biological control projects on terrestrial invasive alien weeds in California

Authors
item Pitcairn, Michael -
item Smith, Lincoln
item Moran, Patrick

Submitted to: California Invasive Plant Council
Publication Type: Other
Publication Acceptance Date: January 13, 2014
Publication Date: February 12, 2014
Citation: Pitcairn, M., Smith, L., Moran, P.J. 2014. Status of biological control projects on terrestrial invasive alien weeds in California. California Invasive Plant Council. 22(1):6-7, 12-13.

Interpretive Summary: In cooperation with foreign scientists, we are currently developing new classical biological control agents for five species of invasive alien terrestrial weeds. Cape-Ivy. A gall-forming fly, Parafreutreta regalis, and a stem-boring moth, Digitivalva delaireae, have been favorably reviewed by TAG, and requests for release permits have been submitted to APHIS. French broom. A psyllid, Arytinnis hakani, that was introduced to Australia and is killing plants, is being evaluated for risk to native North American lupines. The seed-feeding weevil, Lepidapion nr argentatum, is beginning to be studied in France. Russian thistle. A release permit for Aceria salsolae was denied by APHIS in 2006, and additional testing has been done in the laboratory to better describe the level of risk to nontarget plants. The rust fungus, Uromyces salsolae, was favorably reviewed by the Technical Advisory Group (TAG), and APHIS is processing the permit application. Scotch thistle. Three weevils (Larinus latus, Trichosirocalus briesei and Lixus cardui) that have been released in Australia are being evaluated for risk to native North American thistles (Cirsium spp.). Results indicate that the latter two pose risk to native thistles (Cirsium spp.), but Larinus latus may be more specific and is still being tested. Yellow starthistle. Prospective new agents include the rosette weevil, Ceratapion basicorne, a stem-mining flea beetle, Psylliodes chalcomera, an eriophyid mite, Aceria solstitialis, and a seed head weevil, Larinus filiformis. A release permit for C. basicorne was denied by USDA-APHIS in 2006, but additional field and laboratory experiments indicate that there is no risk to safflower under field conditions. Testing of the other prospective agents is ongoing, including field experiments in Turkey and Italy for L. filiformis and in Bulgaria for A. solstitialis.

Technical Abstract: In cooperation with foreign scientists, we are currently developing new classical biological control agents for five species of invasive alien terrestrial weeds. Cape-Ivy. A gall-forming fly, Parafreutreta regalis, and a stem-boring moth, Digitivalva delaireae, have been favorably reviewed by TAG, and requests for release permits have been submitted to APHIS. French broom. A psyllid, Arytinnis hakani, that was introduced to Australia and is killing plants, is being evaluated for risk to native North American lupines. The seed-feeding weevil, Lepidapion nr argentatum, is beginning to be studied in France. Russian thistle. A release permit for Aceria salsolae was denied by APHIS in 2006, and additional testing has been done in the laboratory to better describe the level of risk to nontarget plants. The rust fungus, Uromyces salsolae, was favorably reviewed by the Technical Advisory Group (TAG), and APHIS is processing the permit application. Scotch thistle. Three weevils (Larinus latus, Trichosirocalus briesei and Lixus cardui) that have been released in Australia are being evaluated for risk to native North American thistles (Cirsium spp.). Results indicate that the latter two pose risk to native thistles (Cirsium spp.), but Larinus latus may be more specific and is still being tested. Yellow starthistle. Prospective new agents include the rosette weevil, Ceratapion basicorne, a stem-mining flea beetle, Psylliodes chalcomera, an eriophyid mite, Aceria solstitialis, and a seed head weevil, Larinus filiformis. A release permit for C. basicorne was denied by USDA-APHIS in 2006, but additional field and laboratory experiments indicate that there is no risk to safflower under field conditions. Testing of the other prospective agents is ongoing, including field experiments in Turkey and Italy for L. filiformis and in Bulgaria for A. solstitialis.

Last Modified: 12/19/2014
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