Page 1 - 3 - LESSON NOTES - SILK , LIFECYCLE OF SILK MOTH, PROCESSING OF SILK
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SAI International School
                                                      Class – VII

                                               Subject – Chemistry
                                              Topic –Animal Fibres
                       Sub-Topic-Silk, Lifecycle of Silk moth, Processing of Silk

                                                    Lesson notes
               Life cycle of silk moth:

               Silk moth is a white insect. Different stages in the life cycle of a silk moth are as follows.










































                   1.  Egg: The female moth lays eggs during the summer. The egg hatches in spring.
                   2.  Larva: The eggs hatch in to larva or caterpillars, which feed on tender mulberry
                       leaves. This stage last for 27 days, and during this time, larvae shed their skin in four
                       times. This process is called as moulting.
                   3.  Pupa: Caterpillar spins fine thread around it within three to seven days in layers to
                       form cocoon. Silk threads are obtained from cocoon which colours ranges from white
                       to golden yellow.
                   4.  Silk moth: Pupa changes in to a moth, and comes out of the cocoon. The female adult
                       lays eggs and the cycle continues.





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