There are 4 stages of a butterfly’s life cycle: egg, larva, pupa and adult. First, adult butterfly chooses a plant which is normally the kind of plant that the caterpillar, the larval form of butterfly, can eat, to lay its eggs on the leaves. After hatching, the young caterpillars, known as ‘eating machines’, continuously eat leaves for 2 to 3 weeks. During this time, they grow enormously and will increase their size by a thousand times. Like snakes shedding their skins, caterpillars have to shed their exoskeletons several times to allow their bodies to grow freely. However, some caterpillars only shed once until they reach their maximum body mass. When having grown big enough, the caterpillars stop eating and start to crawl to choose for themselves good stems and branches. They hang upside down by spinning their silk to attach themselves to the plant. This is the time when they are ready to proceed to the next stage of life, chrysalis, the pupal form of butterfly. About 24 hours after being firmly attached to the plant, the caterpillars begin to shed their exoskeletons for the last time to expose the chrysalises.
The chrysalis stage usually lasts for 1 to 2 weeks. Despite the quiet and stable look, the inner parts of the caterpillars which is now the chrysalises, are changing massively inside. Once fully transforming into chrysalises, the caterpillars start to release an enzyme that digests all the tissues into small cells. So the chrysalises are just like bags of cell liquid in the beginning. These little cells are divided into groups called ‘imaginal disks’ that are going to form the adult butterfly’s wings, legs, and all the organs, so that the entire inner part of a caterpillar – the heart, the nervous system, the digestive system, the muscles – has been completely rebuilt. During this stage of development, the chrysalises lose about half of their weight. This leads to the fact that the pupal form of the butterflies burns up a huge amount of their energy saving during their larval form.
THE AUTHOR AND HIS TIMES William Shakespeare lived in a time of great change and excitement in England- a time of geographical discovery, international trade, learning, and creativity. It was also a time of international tension and internal uprisings that came close to civil war. Under Elizabeth I (reigned 1558-1603) and James I (reigned 1603-1625), London was a center of government, learning, ...
After 1 or 2 week, when all the organs are fully developed and ready to function, the butterflies try to come out of the chrysalises. In other word, they are ready to be reborn. To come out, they first release some hormones that soften the chrysalis shells and then push hard. At the first moment being butterflies, they are unable to fly because of their crinkled wings. They have to spend several hours to pump some liquid from their body to harden the wings. As the wings are ready, the butterflies start their final stage of the life cycle. They are going to feed themselves, look for mates and reproduce.