I fed mine quite a few mealies at the start but they grow really really fast and they wont be enough in just a month or two.I feed mine roaches, mealies and pink mice.But crickets will do just as well.I really dont know that I would use "just" mealworms.I worry about impaction with as many as they need to eat.
I know on some of the frog forums they use nightcrawlers that you buy from a bait store as a staple(no shell at all)
Also be sure to get a calcium supplement, they grow so fast they need the calcium.
Ive not tried nightcrawlers yet myself.

I read an article that said they wild they actually eat more frogs then insects.So I think a pink mouse is fine once a week in addition to your insects.You can catch stuff too, like grasshoppers and pull off those nasty back legs and spiders and such.