I have a question I pulled about 30 eggs from black swallowtails off my one fennel plant l that I had and all the eggs hatched now I have a bunch of small caterpillars and I had had three big previous ones and ran out of Fennel. my husband bought parsley from the grocery store and set it I the there with the three big ones then they were about dead this morning and I was
Wondering if there's a possibility there may have been something like pesticides or something on the parsley that wouldve caused this? I've never dealt with this before so I don't know if anybody might have any suggestions on what happened

You would not have residual pesticides on store-bought parsley, or at least you should not. In fact, in all the years of growing parsley, I don't ever remember having any insect that bothered it. Perhaps we just don't have insects with an appetite for parsley.

Ok I've never been able to grow it so I wasn't sure. Just not sure how they just went downhill over night when they were to the point of chrysalis.

I don't know a thing about caterpillars. I am sure there are knowledgeable folks out there that will know their relationship with parsley. Parsley should be very easy for you to grow, from the fall until summer. Hard freezes will do it in and extremely hot weather will also. Otherwise, it grows like a weed.

Let's call on @mellielong and see if she knows what happened. I know she does raise caterpillars to butterflies.

They could have sprayed the parsley with BT which would kill the caterpillars. I have had good luck with buying organic parsley from Publix. It has never killed my cats. You do have to feed them a lot of it, though, since the nutrition factor goes down as soon as it's picked. I don't know if Publix would use the same distributor in Jacksonville, but it's worth a shot. Unfortunately, BT spray is considered organic since it is a naturally occurring bacteria, but so far I've had no problems with the stuff from Publix. I also used organic dill once from them because their parsley looked wilted.

Ken, do you not get Black Swallowtails in your area? Black ST cats are known as the "Parsley Worm" because it is one of their host plants. I'm surprised you've never seen one on yours.

I don't remember ever seeing any sort of caterpillar on my parsley, Mellie. I lost all of my parsley last winter and did not replant any this year. We don't used much of it. We use a lot of chives, both Italian and garlic, rosemary, and basil, so I keep all of that growing year 'round.