I brought some cabbage white larvae inside to show to a group and a couple of days later when I looked at them I saw all these cocoons in a bunch. I can’t quite figure out how they got there since I didn’t see them before. Right now I’ve got the cocoons in a sealed container to see what emerges – we’ll keep you posted. There’s also that little red blob near the top – I’m not sure what that is either. I’m guessing these are wasps. The larvae were inside one of my caterpillars and emerged in this form.
Butterfly Gardening 
Just found some of these! Did you ever figure out what they were?
Parasitic wasp cocoons. The small wasp lay eggs in the caterpillar and the wasp maggots ate and killed the caterpillar. When the maggots were ready to form cocoons they emerged from the caterpillar. Small black wasps will emerge from the cocoons within a week or so.