I just check some of my pets also, good numbers this year. I usually find a handful of the caterpillars but this year I've found way more. Hopefully they are doing better each year. I've been saving seeds and passing them out to help spread some of the weed for a lot of years now. I sprout them in the winter grow tent and plant seedlings each year also.
Now if I can find a way to keep the aphids and what I think are boxelders off the plants I'd be in better shape. Some plants didn't have mature seed pods and I'm thinking the aphid numbers have something to do with it.