Yellow starthistle is an important invasive alien weed of rangeland in the western United States. Ceratapion basicorne is a univoltine weevil that develops in the root crowns of this plant, and is commonly found attacking the plant in its native range, especially in Turkey. A colony of C. basicorne was established in quarantine. No-choice and choice laboratory experiments showed that the insect is specific to a few species in the genus Centaurea. We found no risk to native North American plant species, including those in the most closely related taxa: Cirsium, Saussurea and Plectocephalus (=Centaurea in part). 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. We are recommending the insect for introduction to the U.S.