<P> Silkworm larvae are fed with mulberry leaves , and , after the fourth moult , they climb a twig placed near them and spin their silken cocoons . The silk is a continuous filament comprising fibroin protein , secreted from two salivary glands in the head of each larva , and a gum called sericin , which cements the filaments . The sericin is removed by placing the cocoons in hot water , which frees the silk filaments and readies them for reeling . This is known as the degumming process . The immersion in hot water also kills the silkworm pupa . </P>
<P> Silkworm larvae are fed with mulberry leaves , and , after the fourth moult , they climb a twig placed near them and spin their silken cocoons . The silk is a continuous filament comprising fibroin protein , secreted from two salivary glands in the head of each larva , and a gum called sericin , which cements the filaments . The sericin is removed by placing the cocoons in hot water , which frees the silk filaments and readies them for reeling . This is known as the degumming process . The immersion in hot water also kills the silkworm pupa . </P>
at which stage does a silkworm produce silk thread
at which stage does a silkworm produce silk thread
larvae
larvae