Being a producer of live mealworms I’m always fascinated at what they will eat (which is just about anything), how much they eat, and how fast the mealworms consume their food.
Quick Note: If you are storing your live mealworms in the refrigerator then they will probably not eat anything in that state. They will be fairly dormant. My rule of thumb is once a week take the worms out of the fridge. Let them warm up and then feed them.
1st as a producer of live mealworms in the greater Atlanta, Georgia area I use wheat bran as a bedding. The wheat bran serves two purposes: 1) As I mentioned the bran is the bedding for the entire life cycle process. 2) It just so happens the mealworms eat the bran! In fact if you grow a lot of them they can eat a lot of wheat bran.
We feed our live worms one of 3 things consistently. It’s going to be carrots, potatoes, or apples. They will eat all three. They will also eat cheese (don’t do it they will smell like cheese), lettuce, chicken feed, and I’ve heard also dog food being used (we’ve never tried that one.)
One word of caution. Some “feed” contains a lot more moisture than others. As an example most of the year we try to use carrots. The live mealworms love them and they don’t tend to create moisture problems. As we get into the drier winter months we will use a lot more potatoes. Potatoes in the summer would make it rain in their containers, just too much moisture. But moisture in the winter is needed.
See the video I took below showing the live mealworms eating carrots, potatoes, and apples.