This is a sister thread to the one on Monarchs.
By chance, my wife has started a project of raising Black Swallowtails. The catepillars live on members of the carrot family, incluidng dill weed and parsley and Queen Anne's Lace. My mother-in-law has dill in her garden. My wife picks up the catepillars off of the dill. She puts them in Mason jars stuffed with parsley from the store. She puts a stick in there also.
They eat up the parsley, get fat and then form a chrysalis (if that's the correct term) on the stick. The cocoon dealymajig looks like an extension of the stick, and it brown/grey colored.
The first one she tried this one was in the cocoon for about a week. She put it in a window. It hatched out into a butterfly and was released.
She's got about four more going now. Two of them are in the chrysalis stage and two are almost there. We'll see if they hatch out. It is starting to cool off, and I wonder whether they will have tood weather.
I told her that if she was going to play with bugs, she might as well learn how to help me with the hives. Remarkably, she told me that I should designate my hive that is in our yard as hers and teach her what to do. So I may just have to keep her.
Anyway, if you want to raise butterflies, this method seems pretty easy so far. It helps that the plants that they like to eat are for sale at the grocery store. I bet you could also find a patch of queen anne's lace.