Why do silkworms make silk?
The silkworm undergoes several stages in its life cycle. Egg is one of the stages of its lifecycle. Egg is laid by the female moth during the early fall. The egg will be dormant till the spring. Then the spring heat will make the eggs to hatch. The worm will be in the size of about 1/8th of an inch. They feed on mulberry leaves at this stage. The stage of larva ends by about 27 days. The larval phase has 5 stages known as instars. The larva begins to undergo molting and the first molting results in shedding the hair on the larval surface and it attains a smooth skin.
The silkworm will have one lifecycle in a year. The natural food for silkworm is mulberry leaves. The silkworm will possess two elongated sacs on either side of the silk worm which have opening under the mouth of larva. The opening is called as spinneret or seripositor. The larva will start spinning the cocoon around it in order to protect it from the environment and the predators. After the first molting, cocoon formation will start.
The silk worm larva will eject silk threads from the glands which is about 800 to 1200 yards in length. The silk threads are made by moving its head consistently for 3 days. After about 10 to 12 days of cocoon completion, the insect will escape. The length of the cocoon is 1 Â½ inches. The larva lives inside the cocoon and gets transformed into pupa. The second molting will take place inside the cocoon while the larva converts into pupa. The pupa will take about 2 to 3 weeks to get changed to adult moth. The cocoon color will appear based on the type of food it eats. The silk color can range from white to golden color. The perfect adult moth mates with its opposite sex and after 4 to 6 days, lays eggs of about 500 in number. After the life cycle is completed, the moth will die.