2005 Annual Report 4d.Progress report. This report serves to document research conducted under a Specific Cooperative Agreement between ARS and Cornell University. Additional details of research can be found in the report for the parent CRIS 1907-22620-002-00D "Biological Control of Swallow-wort and Other Invasive Weeds of the Northeastern United States." Exotic swallow-worts possess broad environmental adaptations which allow them to grow in a wide variety of habitats, from agricultural to natural areas and from full sun to full shade. Growth and reproduction are known to be affected by shading but detailed life history data is generally lacking for both species of swallow-wort. In addition, the influence of various soil characteristics on the potential distribution and overlap of the two species is unknown. We will determine the growth, vegetative expansion, and seedling recruitment of individually marked black and pale swallow-wort plants growing in several representative sites in New York State over three years, and assess the effects of soil type, pH, soil depth, drainage and competition from herbaceous vegetation on the performance of the two swallow-wort species in common garden experiments. The results will aid in understanding what factors promote or limit the population growth and spread of exotic swallow-worts, and identify vulnerable life stages to be targeted for management through the use of biological control. Successful biological control will decrease the negative impact of these two exotic invasives in both natural and agricultural ecosystems of the Northeastern United States. Research sites were identified for pale swallow-wort beginning in 2005 and field experiments have been established with the permission of the appropriate owner or authority. Data collection is on-going. Additional field sites for black swallow-wort continue to be selected, and common garden experiments are being established.