When I went to a local reptile expo approx 7 or 8 weeks ago I bought a 100 super worms. I have been slowly feeding them off and attempting to make others morph and still have plenty left. The key to supers is to keep them in a large enough container on 3-4 inches of oatmeal and provide fruits/veggies daily. I also added some egg cartons that they climb and chew holes in. My 100 were fine in a shoebox sized container with air holes punched in the lid. In smaller containers they fight and eat each other even if there is plenty of food. I keep meal worms the same way and have successive generations and a never ending supply.

Anyways, if you separate the meal worms and super worms they can be kept easily and they live a long time.