pupal stage的用法和樣例：
例句
- Peculiarities in the silkworm are known to appear at the corresponding caterpillar or cocoon stage.
蠶體的性狀，亦限於相當的幼蟲期或蛹期出現。 - In general, larva having the lowest survival rate was the main fatal stage during group rearing following by prepupa and pupa.
集體飼育以幼蟲期之死亡率最高，為主要死亡時段，前蛹期次之，蛹期最低。
