After my moths have been used up for breeding or if I have any extra, especially females loaded with eggs, I feed them off. My chams go nuts for the slikmoths. The flapping wings draws the attention from every panther cham in my basement when the moths start emerging. Just make sure you wait until after the moths spit out the nasty brownish liquid they spray out after hatching. One time my cham shot a moth, the brown stuff spray and got all in his mouth while he was chewing and he immediately spit out the moth. After that he wouldn't eat them for a good month. So I'd say after they emerge give them an hour or two just to let them get out their guck. I do not know the nutritional value of them but I imagine that feeding silkmoths once in awhile can hurt, they can't be any fattier than superworms, thats for sure.
Justin