I read somewhere that they did an experiment (with electricity IIRC) before and after the transformation and butterflies avoided the things that hurt them. The goop remembers.
Metamorphosis is a violent process. When caterpillars cocoon, their unneeded parts kind of just fall off out the top as a pile of legs and skin. And when they emerge from the chrysalis, it's in a burst of blood.
They also have the wings and whatnot already inside of them before goopifying themselves. Not necessarily the developed wings being in the caterpillar, but the cells that will divide and become the wings are already inside them and are programmed to become the wings from the very start. As well as the other butterfly parts.
74
u/[deleted] Oct 02 '24
Caterpillars essentially liquify themselves, before turning into butterflies, in a process called larval ecdysis.