LA Pic
Adult mealworms.  Meal "worms" are actually larvae.

Not Worms.  Mealworms, Tenebrio molitor, are insects -- the larvae of a nasty tasting black or very dark brown beetle.  The adults can fly.  The larvae eat all manner of grains.  Of course farmers consider them a definite pest.  They get into the grains they store for feed.  Chickens and ducks go nuts for them.  More important for us, many fish, lizards, and amphibians consider them tasty little morsels.  As do hedgehogs, sugar gliders, and short-tail opossums.

You can "gut-load" your mealworms just like crickets.  Give them the same gut-load food.  They eat at night.  Put it on a flat surface, like a yogurt lid.  In fact, they'd like a bit of that yogurt.  They won't eat much.

Their high protein and fat content really plump up your breeders.
 

http://www.aqualandpetsplus.com/Live Food, Mealworms.htm

LA Pic
Mealworm farmers ship them in bran.  This stays dry better than any other media.

Easy to Keep.  Mealworms come in plastic containers most people store in their fridge.  The larvae go into “hibernation” when cold.  They’ll keep this way for several weeks, maybe months.  In the fridge they eventually dry up and/or get skinny.  You can plump them up by warming them to room temperature and giving them a slice of potato for food and water.  You can juice up your worms by sprinkling their potato slices with powdered calcium and vitamins. 

LA Pic
Mealworms feeding/drinking on a slice of potato.

Moisture.  If you’ve ever kept mealworms you soon notice their feces are dry as dust.  They extract all moisture from their powdery droppings and can live on next to no water.  But if given moist food (potatoes or greens), they multiply in three to four months.  Carrots work also.  Forget apples.  Too much moist food will mold their media.

LA Pic
Adult mealworms checking out a potential egg-laying site.

Females Lay 100-200 Eggs usually on the potato slices.  Baby larvae hatch in about a week.  They shed their skin some 15 times during this larval stage and finally turn into helpless pupae.  Most people feed them out at the larval stage.

LA Pic
Mealworm larvae often eat these pupae.

Take out the Pupae.  The larvae will cannibalize the pupae for their moisture content if you do not remove them.  The pupae turn into egg-laying beetles in seven to 10 days and restart the cycle.