I got a vivarium set up for my carolina box turtle that integrates superworms into it, and they are almost self-sustaining.
This works well, and only works because I keep the turtle in a huge tank and the substrate is potting soil (A little, for color.), peat moss (mostly, prolly 75% peat moss.) and the veggies I throw in for turtle that don't get taken out, as well as whatever the superworms will eat, like oat bran, etc. I run into these guys a lot as I grew up on a farm, they were mostly around the grainery after dark. Much easier to raise than regular mealies. I'm afraid the lizard wouldn't be able to live on mealworm substrate, but my box turtle don't mind.
They will live on peat moss until they find something better to eat. They won't have much nutritional value to the pets, through, unless you gut load them first.
I still buy 100 superworms a month, gut load them, and feed them in a big plate to the turtle. Most of them get away (Into the enclosure.), but not all. Superworms like it warm, 75-80F and just a little damp, but not too humid. I have a warm end, a cool end, a humid end and a dry end, I find them mostly near the humid end.