Thanks brother, glad it made sense.
Wheat bran can usually be sourced from a local feed store. I get a 40lb sack for about $36.
As for the Darkling beetles (mealworm beetles), they can be ordered from Northwest Redworms. If he doesn't have them in stock I could help you out depending on how many you need. His worm castings are the best on the market too...imho. Nobody does composting and castings like that guy!
Another thing about the mealworms. Specifically the pupae...keep the pupae in their own bin. (I like to use an upside down bin lid. Also, the bins I use are 28qt translucent storage bins. They can be sourced a Wally World for $5-6.) The beetle's will eat the pupae too. I put a thin layer of bran on the lid with the pupae on top. The pupae are stimulated by moisture. So I lightly mist chlorine free watering over the top of them once or twice a day depending on the humidity in the house. I get about 30-50 new beetles every day out of each lid. They are put directly into a beetle bin to start breeding and laying eggs.