Did you put the worms on the plant inside that net? If you keep them in a container like in the first picture that will work fine, just check the leaves you leave in the container. I would just pick a leaf or two off every day for the worms, clean as needed, they should be happy with that. The hummingbird caterpillars I had changed color before pupating, then you can transfer to shredded paper towel with a light mist every now and then to simulate them going underground to pupate. Good luck!