Caterpillar pupation is the life stage when a caterpillar turns into a butterfly or moth.
The pupa stage is found only in beetles, butterflies and moths, flies, and wasps, which undergo a complete metamorphosis. They go through four life stages: embryo (egg), larva (child), pupa (pubescence) and imago (adult).
The pupa of a butterfly is called a chrysalis, Moth caterpillars spin a silken cocoon then form the chrysalis inside. Once a caterpillar has all the building blocks it needs to make a butterfly, it finds a safe place to pupate and spins a silken pad. It then uses the cremaster, a hook-shaped protuberance on the rear of the caterpillar, to hook into the silk. Then, it hangs and forms the pupa case under the caterpillar skin, before shedding the caterpillar skin.
Inside the pupa, enzymes are released that break down the body tissue into nutrient rich soup.
It was thought until very recently that the butterfly or moth caterpillar was completely converted to soup, except for special cells called imaginal disks that have the information to build butterfly body parts.
This idea has recently been reviewed with researchers proving that moths retain at least some of the memories they had when they were caterpillars. For this to be the case, at least some of their memory storing neurons must survive the enzyme digestion process. Further, these neurons must somehow be incorporated into the moth or butterfly’s brain, which is quite a bit larger and more complex than a caterpillar’s brain.
It turns our brain into soup just thinking about it!