I've never consider king mealworms because I'd heard they were just a larger version of the standard hard shelled mealworm which I avoid. I can get supers about 20 miles from home, but not at the little local store where I get my crix.
This weekend I looked at the king mealworms at the local store and they looked exactly like supers to me.
What's the difference? Is it visible, and could they be using "king mealworm" as a substitute for "superworm" mistakenly?