Sericulture

 Sericulture is performed widely in many countries. India and China is the leading silk producer in the world. About 60% of the total silks produced are imported from India and China all over the world. Sericulture is the process that consists of the cultivation of silkworms and the extraction of silk from them. The most common species for sericulture is the domestic silkmoth named Bombyx mori.

What is Sericulture?

Sericulture is the process that consists of the cultivation of silkworms and the extraction of silk from them. The most common species for sericulture is the domestic silkmoth named Bombyx mori. There are other types of species as well including Eri, Muga and Tasar which are generally cultivated as wild silks. It is one of the important industries in many countries. Among them, India and China act as leading producers of silk in the world. These two countries import at least 60% of the total silk produced in the whole world. 

What is silk consists of?

Silk mainly consists of sericin and fibroin which are two different proteins. The protein, fibroin is present in about 80% of the total silk. This protein remains in concentrated form in the core. The core remains surrounded by another protein named sericin and consists of the remaining 20% of the total protein. The colour that silk imparts is due to the presence of pigment xanthophylls in the sericin part of the silk. Each variety of silk has different colours. For instance-

The colour of mulberry silk is yellow or green and that of Eri silk is creamy white or brick red. On the other hand, the colour of Tasar silk is copper brown and that of MUGA silk is golden. This is because of the presence of xanthophylls in different proportions.

Process of Sericulture

There are three primary steps followed in the process of sericulture which includes moriculture which is the cultivation of mulberry leaves, silkworm rearing and silk reeling.

Mariculture

This is the process in which the cultivation of mulberry leaves is performed. The leaves of mulberry plants are consumed by the silkworm. This cultivation can be done by three different methods: Cultivation from seeds, root grafting and stem grafting.

Out of these three, stem grafting is the most common procedure on mulberry plantations. Each cutting is about 22 centimetres in length and contains about 3 buds. These cuttings are taken from a mature mulberry plant. These cutting are directly planted or first nurtured in the nurseries and then transported in the field. Mulberry leaves can be harvested from mature plants by different methods which include leaf picking, top shoot harvesting and branch cutting. Leaf picking includes the removal of an individual hand manually. Top shoot harvesting consists of the removal of the tips part of mulberry soot. Branch cutting includes the removal of the entire branch.

Silkworm rearing

The process of silkworm rearing begins with laying eggs by silk moth. About 300-350 eggs are laid at once by the female moth. Those eggs are collected and washed with the help of 2% formalin for disinfection. Then the feeding bed is prepared which consists of chopped mulberry leaves on it. Then the larvae hatched from the eggs are transferred to the try by the process of brushing. Water-soaked foam strips are placed on the tray to provide moisture which is preferable for the growth of the silkworms. The larvae of silkworms initially eat a lot. When they grow, their appetite also decreases a lot up to their active stage. In their active stage, the silkworms eat a lot up to their final feeding stage. After maturation, the larvae look for favourable places for the formation of the pupa. At this stage of their life cycle, the body of the larvae shrinks. These mature larvas then start wrapping themselves forming cocoons by using their saliva from two salivary glands which are present in their head. This saliva solidified and results in the formation of silk. 

Silk reeling

The final stage of sericulture consists of the harvesting of silk. The pupae that are formed inside the cocoon by metamorphosis are killed by boiling and then they were exposed to steam and dry heat. This procedure is known as stifling. After that, the silk filaments are removed from the dead cocoon by the process of reeling. When the cocoons are boiled, the adhesion between the threads decreases which enables easy separation of threads. These filaments of silk are twisted to give it the structure of thread. The silk thread is then re-boiled to improve its structure and lustre. 

Conclusion

Though this is a profitable business, there are some challenges in the process as well. A lot of diseases like pebrine disease can affect the eggs and cause premature death of the larvae. Viral infections can also affect the larvae. Some muscardine infection by fungi can also make the larvae extremely feeble and also results in death. Despite all these, sericulture can be profitable for cultivators to a huge extent.