I had 10 swallowtail butterfly caterpillars on my dill and parsley. First they ate all of the dill and then ate all of the parsley. They left the plants and looked for a pupation site. I was able to find the site of 3 of the 10. One of the 3 did not make it. I have 2 chrysalis that I am watching. The larvae secured themselves to my deck with their hooks and silk girdle. They then shed their skin for the last time (it is still somewhat attached at the bottom of the photo) revealing the pupa underneath. Stay tuned (stays in chrysalis for 10-14 days).