Hi Robert, that’s a good question. I believe that labor is highest when replacing the insects’ water source, which in this case is raw carrots and/or potatoes.
Considering moisture is the main requirement for these insects, a water delivery system is crucial, and the vegetable matter secondary in importance for nutrients. The dry feed itself can be fortified for a better nutritional profile.
It is important to note that any kind of broad moisture application to feed is dangerous to the operation since mold is the biggest threat to mealworms, so simply spraying the wheat bran media cannot be considered.
Humidity is also a factor that must be considered. For example, it would be as detrimental to the micro-environment to have a sponge periodically be sprayed and have it be available for the mealworms, as the relative humidity would greatly increase from having a perpetually wet sponge present in the micro-environment. Any sharp increase in humidity will help provide mold with a better environment to grow. Humidity is best kept around 75%.