Crickets are probably the most common 'staple' food. If you mean grasshoppers, then I would assume at 4-5 months old, they are too big for him. Any live feeder that you give to your beardie should be no larger than the space between his/her eyes.
There are lots of good feeders out there, check around this forum for some more ideas.
if you mean hoppers as in baby mice, that is not ok. mice have too much fat/phosphorus and too little protien/calcium.
if you mean grass-hoppers, that is also not ok. wild caught grasshoppers could have deseases or pesticides on/in them.
use store-bought or farm-raised crickets, dusted with calcium powder containing NO phosphorus but WITH D3. roaches are even better bet a bit costly unless you breed your own. check this site out: http://www.bestroach.com
i use roaches, superworms(for my big dragons), crickets and various healthy veggies.