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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 yellow starthistle, Russian thistle, Scotch thistle, Cape-ivy and French broom

Author
item Smith, Lincoln

Submitted to: Weed Science Society of California Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: January 24, 2013
Publication Date: N/A

Interpretive Summary: The USDA-ARS quarantine laboratory in Albany, CA, in cooperation with foreign scientists, is currently developing classical biological control agents for five species of invasive alien terrestrial weeds. Host specificity testing of the yellow starthistle rosette weevil, Ceratapion basicorne, indicates that it does not attack safflower under field conditions and that it has low preference for bachelor's button. Host specificity tests are being conducted on a weevil, Larinus filiformis, that attacks seedheads. The eriophyid mite, Aceria salsolae, which stunts Russian thistle, can attack six closely related species of Salsola and sometimes multiply on Bassia hyssopifolia and Bassia scoparia in no-choice laboratory experiments. A stem-boring seed-feeding caterpillar, Gymnancyla canella, is being evaluated for specificity. For Scotch thistle control, 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.). A petition has been submitted to USDA-APHIS requesting permission to release two agents of Cape ivy: a gall-forming fly, Parafreutreta regalis, and a stem-boring moth, Digitivalva delaireae. For French broom, a psyllid, Arytinnis hakani, that is killing plants in Australia is being evaluated for risk to native lupines.

Technical Abstract: The USDA-ARS quarantine laboratory in Albany, CA, in cooperation with foreign scientists, is currently developing classical biological control agents for five species of invasive alien terrestrial weeds. Host specificity testing of the yellow starthistle rosette weevil, Ceratapion basicorne, indicates that it does not attack safflower under field conditions and that it has low preference for bachelor's button. Host specificity tests are being conducted on a weevil, Larinus filiformis, that attacks seedheads. The eriophyid mite, Aceria salsolae, which stunts Russian thistle, can attack six closely related species of Salsola and sometimes multiply on Bassia hyssopifolia and Bassia scoparia in no-choice laboratory experiments. A stem-boring seed-feeding caterpillar, Gymnancyla canella, is being evaluated for specificity. For Scotch thistle control, 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.). A petition has been submitted to USDA-APHIS requesting permission to release two agents of Cape ivy: a gall-forming fly, Parafreutreta regalis, and a stem-boring moth, Digitivalva delaireae. For French broom, a psyllid, Arytinnis hakani, that is killing plants in Australia is being evaluated for risk to native lupines.

Last Modified: 7/23/2014
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