The Oregon Department of Agriculture used to have a program where cinnabar moths could be obtained, but they do not currently. The moths have had an established population in the Willamette Valley, and are still present along with a couple other biological control agents, however this year I have had many requests for the cinnabar moth, so perhaps population dynamics are changing.

Below are some links to information about managing tansy ragwort:

http://extension.oregonstate.edu/douglas/sites/default/files/documents/tragwortupdate2011.pdf

https://pnwhandbooks.org/weed/problem-weeds/ragwort-tansy-senecio-jacobaea

You might also contact the ODA Noxious Weed Program and let them know of your interest in the cinnabar moth program. Good luck in your battle against tansy ragwort.