Submitted to: Government Publication/Report
Publication Type: Government Publication
Publication Acceptance Date: January 30, 2006
Publication Date: January 25, 2006
Citation: Smith, L. 2006. Proposed field release of the weevil, ceratapion basicorne (coleoptera: apionidae), from turkey for biological control of yellow starthistle (centaurea solstitialis) in the United States. Petition submitted to Technical Advisory Group, USDA-APHIS Technical Advisory Group. (Government Publication/Report). 138 p. Interpretive Summary: Yellow starthistle is an important alien weed that has invaded over 20 million acres in the western U.S. It is spiny plant that interferes with grazing livestock and outdoors recreation, it is fatally poisonous to horses, it outcompetes desirable vegetation, and reduces biodiversity. Previously introduced biological control agents became established but are not providing sufficient control of the weed. We have evaluated a root-feeding weevil (Ceratapion basicorne) of this weed and are submitting this petition to USDA-APHIS to request permission to introduce it as a classical biological control agent. This weevil should help reduce the populations of this weed to innocuous levels over extensive regions. Successful biological control will provide self-perpetuating long-term management of this weed, reduce the need to apply herbicides, and increase the productivity and utility of millions of acres in the western U.S.
Technical Abstract: We are submitting a petition to the USDA-APHIS Technical Advisory Group (TAG) requesting permission to release the weevil, Ceratapion basicorne, whose larvae develop inside the root of yellow starthistle (Centaurea solstitialis) rosettes in the early spring. The insect has a wide geographic distribution in Eurasia and infests up to 100% of yellow starthistle plants at sites in Turkey. A colony of C. basicorne was established in the quarantine laboratory in Albany, CA in 2001. No-choice and choice laboratory experiments showed that the insect attacks only a few species of plants in the genus Centaurea. We found no risk to native North American plant species, including those in the most closely related genera: Cirsium, Saussurea and Plectocephalus. Three years of field experiments in Turkey confirmed that the insect does not attack safflower (Carthamus tinctorius), which is in the same subtribe (Centaureinae) as the target weed. Bachelor's button (Centaurea cyanus) is at some risk of attack, but this is not likely to be significant. We are recommending the insect for introduction to the continental U.S.