蛹壳

例句：

1. 1. The caterpillars emerge from their chrysalises to become butterflies.
   毛毛虫从它们的茧中孵化出来变成蝴蝶。
2. 2. The caterpillar's cocoon is made of silk, which protects the larva during its transformation.
   蚕的茧是由丝制成的，这在它的变态过程中保护了幼虫。
3. 3. The cocoon of a moth is a protective covering that shields the pupa as it undergoes metamorphosis.
   蛾的茧是一种保护性的覆盖物，它使蛹在变态过程中得到保护。