2005 Annual Report 4d.Progress report. This report serves to document research conducted under a specific cooperative agreement between ARS and the University of Cukurova. Additional details of research can be found in the report for the parent CRIS 5325-22000-020-00D Biology and Management of Invasive Weeds in the Western US. Field studies were conducted in southern Turkey to determine the life history of yellow starthistle in order to compare it to that of the plant in California, where it is highly invasive. Specimens of insects attacking roots of several species of thistles (Cardueae) near yellow starthistle were collected for identification to determine if the prospective biological control agent, Ceratapion basicorne, attacks these plants in the field.