There are 3 or 4 different kinds I think all with different cycles. Some come back every year, some after several years and some for the 17yr cycle. If you google it there are different schedules in each state as to when certain species will emerge from the ground. Even if you wait a year for your cham to get bigger I think it would be hard pressed to eat a fully grown cicada. They get pretty big and I think they have a relatively hard exoskeleton. I personally would not risk feeding such a large bug to my cham.