you can change up his diet now if you want. There really is no set time frame. I would try some small silkworms, Horns are good too, but will grow too big too fast for you I think. If you can find any SMALL superworms also. They seem to be a favorite with alot of chameleons! I look at it this way with variety, in the wild they have access to numerous bugs from the day they are born. I would say the only downside is sometimes they start favoring the worms over crickets, but not always.