Question

Write a brief account of sericulture.

Answer 1

Hint: Sericulture, the production of raw silk through the rearing of caterpillars (larvae), in particular domesticated silkworms

Complete answer:
Sericulture is the method of silkworms being grown and silk harvested from them. The most widely used silkworm species in sericulture are the caterpillars of the domestic silkmoth (also called 'Bombyx mori'). Other forms of silkworms are also cultivated for the production of wild silks (such as Eri, Muga, and Tasar).
Sericulture in many countries is a very important domestic industry. India and China are the leading silk producers worldwide. More than 60 percent of global production accounts for the silk output of these two countries combined.
The sericulture method follows three primary steps for the production of mulberry silk.
Moriculture-the cultivation of leaves of mulberry.
Silkworm rearing-promoting the silkworm development.
Silk reeling-the silk filament extraction from the silkworm cocoons
Finally, in order to form a thread, the silk filaments are woven together. To form a yarn, these threads are sometimes plucked together.
Moriculture:
It refers to the cultivation of mulberry plants, the leaves of which are used as feed for silkworms. Three different methods allow these plants to be grown:
1.Culture from seeds
2.Root-grafting
3.Stem Grafting

The most widely used technique for mulberry plantation is the stem grafting technique. From the stem of a mature mulberry plant, cuttings that are approximately 22 centimetres long, containing at least 3 buds, are extracted here. These cuttings can be planted directly or first held in nurseries and then in transplanted.

The mulberry leaves can be harvested through the following methods from the plants:
Leaf picking-the hand removal of individual leaves.
Branch cutting: elimination of the branch as a whole.
Removal of the mulberry shoot tops for top shoot harvesting.
It is important to note that 1 kilogramme of mulberry leaves (from the egg stage to the cocoon stage) will feed approximately 50 silkworms.
Silkworm Rearing
The silkworm rearing process in sericulture starts with the laying of eggs by the female silk moth. 300-500 eggs are usually collected from one female silk moth. With the support of a 2 percent formalin solution, these eggs (laid on a paper/cardboard sheet) are then disinfected.

On a rearing plate, a feeding bed is prepared by sprinkling chopped mulberry leaves onto it. Through a method known as brushing, the hatched larvae are moved into this tray. Foam strips are soaked in water and put on the tray in order to preserve humidity.
Initially, the silkworm larvae have a strong appetite. Their appetite slowly decreases as they develop, until their active stage. The silkworm feeds enthusiastically at this stage before its final stage of feeding.
The larvae begin searching for hospitable places after reaching maturity to begin their pupation. The body of the silkworm shrinks and becomes translucent at this point. By secreting saliva from the two salivary glands on their heads, these mature larvae now cover themselves up in a cocoon. This saliva solidifies as it comes into contact with air and becomes silk.
The cocoon is usually spun within 2-3 days. Some silkworm varieties can, however, take up to 4 days to spin their cocoons.

Silk Reeling
The larvae undergo metamorphosis within the cocoons and develop into pupae. The final step of sericulture is the processing of silk from these cocoons. Second, by boiling the cocoon and exposing it to steam and dry heat, the pupae are killed inside the cocoon. This mechanism is called stifling.
Now through a method called reeling, the silk filaments are removed from the dead cocoon. The adhesion of the silk threads decreases when the cocoons are put in boiling water for about 15 minutes, allowing the separation of individual filaments. With the assistance of a set of guides and pulleys, these filaments are twisted into a thread. In order to improve its lustre, this silk is then re-boiled.
Approximately 50 silk filaments contain one thread of silk. However from a single cocoon, over 900 metres of filament can be obtained. Raw silk is thus harvested from the silkworm and the process of sericulture is completed.

Note: There are several challenges faced by silk farmers practising sericulture that could potentially destroy their harvest. They are also susceptible to many health risks. Silkworms, such as pebrine and flacherie, are vulnerable to several diseases. Several pests are also endangering the healthy growth of silkworm larvae.