Most worms can be fed to Frontosa........people have alot of success with nightcrawlers, but I haven't tried it. They are high in protein, will increase growth in juvies and induce spawning in adults.
With juvies, chop them up and feed them.
Blood worms will increase growth in juvies. Stay away from Tubiflex worms as they are more likely to carry pathogens and disease.
I would recommend this as an occassional treat and not a staple.
As a staple they should be fed a pellet as stated by Red Devil.