The only major difference is size and color for pupa. Bear in mind you have 3 stages.
Pupa that are still in the pupating stage as a rule within a pupal case. Fish look for these at the river bed.
The emergent stage when they swim to the surface. Fish will take these at any depth within from the river bed to the surface, typically look for shoal water below riffles and tail outs.
The transitional stage to the adult. Almost always a surface feeding activity.
The number 1 pupa for me that covers the ascending and transitional pupa is the SLF Trans caddis pupa, with and without a bead head. In sizes 12 to 18 in colors of. Tan/cream/insect green/orange/dark olive.
I would back this fly on any water moving or still during caddis time and for that matter many others.
Davy