What role do caspases play in a butterfly's metamorphosis?

It's not surprising that we don't tell kids what really happens to caterpillars inside a chrysalis. Metamorphosis is pretty gruesome stuff, involving flesh-dissolving enzymes and limbs, wings and genitals bursting through what's left of all that tissue. No wonder the whole thing is done behind closed skin.

But to build a butterfly you have to break down a caterpillar.

The cells that make up the caterpillar's muscles, gut and salivary glands are destined to end up as spare parts for the greater-butterfly-good. Each cell is poised to self-destruct during metamorphosis by activating some of its own enzymes, called caspases.

Like digestive enzymes, caspases tear through the cell's proteins, releasing prime butterfly-making material.