The caterpillar's skin is shed for the last time as it passes from the larval (caterpillar) stage to the pupa (chrysalis) stage of metamorphosis. Under the caterpillar's skin this time is a jade green casing which is called a chrysalis. Inside the chrysalis, which is only about an inch long, the caterpillar will miraculously transform into a beautiful butterfly.Monarch pupa or chrysalisImmediately after the skin is shed, the chrysalis is very soft. Within an hour though, it hardens to become a protective shell for the caterpillar inside. Looking at picture, you can still see the ribbed body of caterpillar in the newly formed chrysalis on the left. The chrysalis on the right has hardened to become a beautiful jade green shell. Dramatic changes occur inside the chrysalis. The mouth parts must go from being those required for chewing (what the caterpillar needed to eat milkweed leaves) to what a butterfly will need: a straw-like tongue used for sipping nectar from flowers. And a creepy, crawling insect will become a flying insect, one of the most beautiful insects on earth!
