[JayArndt]

Are the pupa bigger or smaller than the worm? And when they turn to beetles do the beetles start off small and grow or does the pupa turn into a full grown beetle?

[Mgecko]

The mealworm is the larval or juvenile stage of the beetle. And the beetle is the full grown adult form. Insects that pupate dont generally change size once they've emerged in their adult form. Leastways, i havent heard of any that do.... The adult form size can sometimes be determined a bit by the nutrition or amount of food they get while in their larval form

[Mgecko]

I dont know bout the size of the pupa though it would certainly be shorter than the mealworm itself. A google image search for mealworms should show pics of their various life stages

[For The Sake Of Revenge]

The pupa are around half the size of a full grown worm, generally I haven't noticed the beetles increase in size when I was keeping meal worms. The only thing that changes is the color of the beetles. First they'll come out white then turn to brown then to black as their exoskeletons harden. Some beetles will big bigger then others though just like not all worms will be the same size etc...