yea i dont think they would be a good feeder if thats what you want to do with them. they probley wouldnt hurt either, like you stated they dont eat in their adult stage, so they probley have no nutritional value either. maybe just as a stimulant might be ok. id google it and see if they are toxic or anything
They have a lot of acid in them. When you hit them with your car their insides eat the paint off of your car. I would highly discourage you using these as feeders.