You can, but dont put them directly into the fridge. If you have a room, that is a little cooler and not much light then they will diapose themselves.

Ok I will try that. Thanks!

From the research I've read on other Leps, putting them in the fridge until next year when they are programmed to eclose this year will kill them. If you want them to eclose next year, limit the amount of light they experience as caterpillars.