Question

What is stifling?

Answer 1

Hint: The process of stifling is done by the methods of sun drying or giving steam or hot air. This process is done in sericulture for obtaining silk from the silkworms. It helps in preserving silk for a long duration.

Complete answer:
The process of rearing silkworms and producing silk is known as sericulture. The insect which yields silk is known as Bombyx mori. It feeds on the mulberry leaves. The life cycle of the moth includes the egg, larva, pupa, and adult. The larva stage or the caterpillar makes a cocoon around itself which is the silk thread. The pupa breaks the cocoon and emerges as an adult moth.

In order to obtain the silk, the cocoon has to be heat dried or kept in the hot sun to kill the pupa so as to obtain the fine silk thread. The method of heat drying or applying hot air or steam to the silk cocoons to kill the pupae is known as stifling. The process of heat application or using hot water is done for several hours to several days. This helps in preventing the emergence of math thereby preserving the cocoons and silk for longer durations.
If the process of stifling is not done then one single long thread of the silk will not be obtained. Hence stifling is one of the necessary steps in sericulture.

Note: The process of stifling is done before the process of reeling. The silk is a filament that is made up of fibroin protein. This protein is secreted by the salivary glands which are present in the head of the worm. The gum called sericin is secreted along with the protein which helps in cementing the filament. Stifling helps in removing the sericin from the cocoon so that the peeling process can be done easily.