Pale swallow-wort, also known as dog-strangling vine (Cynanchum rossicum), and black swallow-wort (Cynanchum louiseae) are invasive perennial plants found in parts of Canada, such as southern Ontario, and in parts of the West, Midwest and Northeast in the United States.

They are members of the milkweed subfamily (Asclepiadaceae) and are found in open or prairie habitats, as well as in forests. In addition to forming dense monocultures in formerly native habitats, they may fool monarchs into mistakenly laying eggs on the vine, which cannot support monarch larvae. The plants may also invade agricultural fields and pastures.

These documents provide best management practices specific to the control of this plant. Integrated pest management is emphasized, including the use of mechanical methods, chemical controls and prescribed burning (Anderson 2012; MJV 2015).

• Anderson, H. 2012. Invasive Dog-strangling Vine (Cynanchum rossicum) Best Management Practices in Ontario. Ontario Invasive
• Plant Council, Peterborough, ON. http://www.ontarioinvasiveplants.ca/wp- content/uploads/2016/06/OIPC_BMP_DogStranglingVine.pdf
• Monarch Joint Venture (MJV). 2015. Invasive Species Alert: Black swallow-wort (Cynanchum louiseae) and pale swallow-wort (Cynanchum rossicum). http://monarchjointventure.org/images/uploads/documents/Swallow-wort_flyer.pdf

Keywords: eradication, invasive, mechanical treatment, mowing, native, pesticide, prevention, seeding