I used a lot of oatmeal and then a "dryish" source of moisture. Follow some links here. You probably don't need to calcium load the mealworm food. My suggestion is to make mealies a treat only, don't over feed them.
Beware of moisture in the farm substrate. Your get bugs and theyre near impossible to get rid of. I used a small PC fan to keep the air moving out of the mealie box.
http://www.sugarglider.com/gliderpedia/index.asp?MealWorm