SERICULTURE

Sericulture or silk farming is the rearing of silkworms for the production of raw silk.Sericulture is an agro-industry comprising three components : cultivation of food plants of the worms, rearing of the silkworms and reeling and spinning of silk.The first two are agricultural and the last one industrial component.So, we can tell Sericulture is one kind of bio-agro-industry.Sericulture is associated with the human labour,contribution of plant and sacrifice of the life of silkworm.

History of Sericulture :

The culture of silkworms began in Chaina about 5000 years ago.The ancient chinese were the first  to discover that the cocoons of a lowly caterpillar could be unwound and the filaments woven into some of the most beautiful fabrics in the world.Silk was so highly prized that the lustorus fabrics were reserved exclusively for the Royality of Chaina.

SHORT HISTORY OF SERICULTURE IN CHINA

 The secrets of silk production were closely guarded by the Chinese for thousands of years.It was not until about 300 A.D., that sericulture spread to Korea and from there to Japan.In 522 A.D. Two Nestorian monks,under orders from the Emperor Justinian,smuggled silkworm eggs from Chaina and bought them to Europe.This was the beginning of silk industry in the West.Sericulture spread rapidly throughout Europe and Asia during following centuries.

Kinds of silkworms based on host plant :There are four kinds of natural silk, which are commercially known and prodeced.Commercially important kind silkworms fall into category of mulberry silkworms and non-mulberry silkworms namely :Eri silk, Tasar silk and Muga silk. 

SILKWORM AND COCOON

(1)Mulberry silkworms :These silkworms feed on mulberry plant's leaves. Among  the different kinds of silkworms mulberry silkworm is the most important and contributes as much as 95% of world production,therefore ,the term "silk" in general refers to the silk of the mulberry silkworm. 

MULBERRY SILK

MULBERRY PLANT

Classification based on number of generations produced in a year under natural condition : 

(a)Univoltine :They produced only one generation in a year.Usually these races are found in European countries.

(b) Bivoltine :They produce two generations in a year.They are available in Europe and Japan and produced medium sized cocoons.

(c)Multivoltine:They are able to produce many generations in a year and small sized cocoons.They are available in Pakistan,Bangladesh, India and Chaina.

(2)Non-mulberry silkworms :These silkworms feed on other than mulberry plant's leaves.

(a)Eri silkworms :They produce a white or brick-red color silk, popularly known as eri silk.

ERI SILK

(b)Tasar silkworms :They all are wild silkworms.There are many varieties such as :

TASAR SILK

 #Chinese tasar silkworms: They produce grey-brown cocoons.

#The Indian tasar silkworms

#Japanese tasar silkworms :These types of silks are used in Japan and Chaina in the purpose of embroidery and sewing.

(c)Muga silkworms:They produce an unusual shining golden-yellow silk thread which is very attractive and strong.

MUGA SILK

 Production :

Silkworm larvae are feed mulberry leaves,and after the fourth moult,climb a twig placed near them and spin their silken cocoons.The process is achieved by the worm through a dense fluid secreted from its structural glands, resulting in the fiber of the cocoon.

SILKWORM IN MULBERRY LEAVES

The silk is a continuous filament fiber consisting of a fibrion protein, secreted from two salivary glands in the head of each larvae  and a gum called sericin,which cements the two filaments togther.The sericin is removed by placing the cocoons in hot water, which frees the silk filaments and readies them for reeling.The immersion in hot water also kills the silkworm pupae.This is known as degumming process.

boiling of silkworm cocoon for meaking thread

             single filaments are combined to form thread. This thread is drawn under tension through several guides and wound onto reels.The threads may be plied together to form yarn.After drying the raw silk is packed according to quality.

Importance of sericulture in developing countries :

Sericulture provides gainful employment, economic development and improvement in the quality of life to the people of rural area and therefore it plays an important role in the anti proverty programme and prevents migration of rural people to urban area in search of employment.

Multipurpose use of sericulture :Apart from silk, there are several by-products from sericulture.The mulberry fruits are very rich in minerals and vitamins and from roots, barks and mulberry leaves several ayurvedic and herbal medicines are prepared.Some of the woody mulberry trees provide timber which are resistant to termites and timber is used to prepare sports item.The silkworm pupae are rich in oil content which is used in cosmetic industry and the remaining pupal cake is source of protein content suitable for fisheries and poultry.Silkworm litter is used in bio-gass production and used as fuel for cooking.Thus sericulture not only provise fashionable clothings, it also provide very useful by products to human society.

Present global silk production is fluctuating around 70,000 to 90,000 and the demand for silk is annually increasing by 5%.With the increase in population and also with the increased demand for fashionable clothing item due o fast changing fashion designs in developed countries,the demand for silk is bound to increase even more. For increasing silk production we require highly productive mulberry varieties and silkworm races tolerant to adverse climatic condition and disease which can come mainly from the sericultural germplasm resources and also from wild variety of Bombyx available in natural habitat.