2011 Annual Report 1a.Objectives (from AD-416) Yellow starthistle and Scotch thistles are important invasive weeds in the western USA that originated from the Mediterranean Region. Little is known about insects attacking these plants in Turkey. We will determine the identity, host specificity and impact of insects attacking these plants in Turkey to assess their potential as biological control agents. 1b.Approach (from AD-416) Surveys will be conducted in Turkey to find insects that attack yellow starthistle and Scotch thistle. The taxonomic identity of insect species will be determined, and information on geographic distribution and known host plants will be summarized. Experiments will be conducted to evaluate the host plant specificity and potential impact on the target weed of the most interesting insect species under field and/or laboratory conditions. Live specimens will be sent to the USDA-ARS quarantine laboratory for further host specificity studies with native North American plant species. Formerly 5325-22000-020-46S (2/11). 3.Progress Report Exploration was conducted in the Mediterranean region for prospective biological control agents of yellow starthistle and Scotch thistle. Two species of insects were sent to our quarantine laboratory for host specificity evaluation: Lixus cardui for Russian thistle and Larinus fliformis for yellow starthistle. Colonies of these insects were established in our quarantine laboratory where we are conducting experiments to evaluate host plant specificity. Planning, reporting and analysis were conducted by email and periodic meetings, and an onsite visit in June 2011.