I don't know if there's a way to tell the difference between the worms, the the female beetles are larger than the males, and once they're full of eggs, their abdomens get very large a push their wings out slightly, so they're fairly easy to spot.
I believe each female will lay around 500 eggs in her lifetime of 4-5 months, however they won't all hatch. Maybe 50 or so from each female will hatch.