So bug bites as already mentioned appear to be nearly universally eaten by everything in the tank.
As for other dried food for cories well here's what i do if i'm going to the effort of not throwing in frozen bloodworm.
I take Freeze dried bloodworm, tubifex, blackworm, daphnia (or any combination of the above ) soak in alittle water. Squeeze out the water whilst mushing together. Break into pieces squeeze out any remaing water and when dropped in tank they should sink. Sit back and watch the food fight ensue
But seriously cories not eating try Live or frozen foods.