dry cat food + chicken mash, grounded up in a fine powder. Use ghann's water source feeds and fresh oranges are excellent for providing tons of sweet juice for them, dubia love sweets. This is for raising breeders.
Here is what I do for ours, I vary the recipe and have several varieties in the fridge. this is for feeders (after colony is established)
http://www.youtube.com/watch?v=BlM9RaCBt_M