Utricularia pods are very frustrating. One day a pod full of unripe seeds, the next open pods containing zilch. I have taken to bending the scape down, and affixing it with a bit of tape, CAREFULLY, to the side of the pot, so that the scape is horizontal, and then place an envelope directly beneath the pods, aiming to get the pods inside the envelope as much as possible. If I miss the pod opening, some seed makes it into the envelope. Seed pods that are closed, but brown, probably have ripe seed.