Procuring Cinnabar Moths
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:
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.