2011 Annual Report 1a.Objectives (from AD-416) The objective of this cooperative research project is to develop methods to use eriophyid mites for biological control of weeds. 1b.Approach (from AD-416) We will conduct research on the taxonomy, behavior and ecology of eriophyid mites associated with noxious weeds such as yellow starthistle and Russian thistle. 3.Progress Report Progress was monitored periodically by email. We conducted experiments to further evaluate the host plant specificity of Aceria salsolae, a prospective biological control agent of Russian thistle. A manuscript was submitted on host plant specificity of Aceria solstitialis, a prospective biological control agent of yellow starthistle.