There’s not much information on the internet about breeding them for reptile food (I never found any), but if you look hard enough you’ll find that they’re used for composting, so they can’t really be that hard to breed. The only main concern I would have is that the adult form is a moth, so you’d most likely need a screen container, with a lower proportion that can hold solid food for the larvae.
u need substrate such as dirt and most likly one of thses big things im sorry i forgot the name but it cost sevral hundred dollars u could do it in ur garden but..... u would have introuduced harvster flies into ur eco system...