Zūhiroi: Moving the Silkworms
When a silkworm larva finishes its fifth instar, it is fully mature and weighs 10,000 times more than when it hatched. Having eaten all the food it will eat in its lifetime, the silkworm lifts itself up from its bed of mulberry and starts to sway back and forth, looking for a perch to begin spinning its cocoon.
At this stage, the silkworms are called zū. The process of picking them out from their immature peers is called zūhiroi, which literally means “picking up the ready silkworms.” Changes in appearance and behavior are the key signs that the silkworms are ready to be moved to the mabushi, a scaffold-like structure designed to encourage them to spin their silk cocoons.