Okay, first the Zebra ST. They just need a little time to pump their wings. They do not need to eat for a while. They are way more interested in mating. I've had them come out in the evening and spend the night in my house and then I release them in the morning and they're fine. You don't need to feed them. If they don't fly away when you release them, put them on a plant in a sunny area. Butterflies are cold-blooded and use solar energy to warm themselves. If you found it that way and it doesn't look "normal" within half an hour it's wings are damaged and it will not be able to fly right. The best thing to do in that case would be to euthanize it.
Yup, those are Black STs, also known as the "Parsley Worm". When they get big enough, they will gut purge (looks like caterpillar diarrhea) and then go into a "wandering phase" to find the perfect spot to pupate. You may find them quite a distance from where they started.
