Tags: More interest things about Cocoons

Silkworm is a kind of natural insect. It comes out from 2 millimeters egg. Eggs take about ten days to hatch. Silkworms have a strong appetite, as do all lepidopteran larvae. They eat day and night, preferring White Mulberry but they also take other species of Morus and some other Moraceae. Hatchlings and second-instar larvae are called kego (毛蚕, hairy silkworm) in Japan, or chawki in India. They are covered with little black hairs. When the color of their heads turns darker, it means that it is time for them to molt. Later instars are white, nude, and have a horn on the back. [NOTE: instar = a phase between two periods of molting in the development of an insect larva or other invertebrate animal.]After they have molted four times (i.e., in the fifth instar), their bodies turn slightly yellow and their skin becomes tighter. The larvae enclose themselves in a cocoon of raw silk produced in the salivary glands that provides protection during the vulnerable, almost motionless pupal state. Many other Lepidoptera produce cocoons, but only a few large Bombycidae and Saturniidae have been exploited for fabric production.