In creating our flowerbeds this year I insisted on leaving some milkweed growing in one bed. 
Today, as we were digging out hostas to rearrange them, I was informed by my coworkers that caterpillars were eating those milkweeds. I got excited! Sure enough, it was a monarch caterpillar! (We only found one.)
But as you can see from the picture, the milkweed themselves were not looking good. They seemed to have a black mildew or fungus growing on them. I thought surely that isn’t good for the creature. Plus, we didn’t want that on all the other plants, and it was definitely spreading.
First I took the little worm and put it into a container with his leaf. Then we pulled all the milkweed plants (roots stayed in the ground for next year). Then I pulled all the pods off the plants. I hope the seeds inside are mature enough. I’m going to let them dry, then I will release them into the wild — beside our new sound wall. I hope some of them will grow.
This afternoon I carried the wee stripey fellow over to Cheryl’s house (doesn’t take it long to polish of a leaf, I had to get some more out of the garbage for him for the journey) and left him on a healthy looking plant.
I hope this caterpillar continues to eat and grow and make a lovely chrysalis, that it becomes a healthy butterfly so it can fly all the way to Mexico! (Perhaps it will stop over in California and visit my grandkids, too.)
Learn more about caterpillars and butterflies: http://www.thebutterflysite.com/life-cycle.shtml