2006 Annual Report 4d.Progress report. This report documents research under a Specific Cooperative Agreement Number 58-6206-6-0014 between ARS and Dr. Allen Knutson, Texas A&M University, Texas Agricultural Extension Service, Dallas, Texas. Additional details of research can be found in the report for the parent project 6206-22000-006-00D Biological Control of Saltcedar, Russian Olive, and Other Invasive Weeds in the Western USA. This Specific Cooperative Agreement was established to facilitate joint research between ARS Temple, TX, and Texas Agricultural Experiment Station, Dallas, on biological control of saltcedar. An analysis of decreasing carbohydrate levels in saltcedar trees resulting from increasing defoliation of the trees by the Diorhabda beetles was conducted in cages at Lake Thomas, TX, and in the open field at Lovelock, NV, by Texas A&M University Masters Degree student Jeremy Hudgeons. The research is completed and the thesis is in preparation.