- Related Topics:
- Origins of agriculture
- silk
- How is silk made?
sericulture
News •
-
What is sericulture?
Sericulture is the production of raw silk by raising silkworm caterpillars, especially those of the domesticated silkworm (Bombyx mori). Silk production involves caring for the silkworms from the egg stage through cocoon completion and cultivating mulberry trees to feed the worms.
The silkworm caterpillar creates its cocoon using a long, continuous fiber or filament. This filament is produced from liquid secretions from glands within the silkworm, which harden when exposed to air. The larva is killed by steam or hot air at the chrysalis stage to preserve the cocoon filament. The silk is then unwound from the cocoons, and several strands are twisted together to make yarn.
3 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
Which insect is mainly used in silk production?
The insect mainly used in silk production is the silkworm moth (Bombyx mori). Sericulture is the process of raising silkworms to produce raw silk. These caterpillars are fed mulberry leaves until they are ready to spin a cocoon made of a continuous fiber produced from a protein called fibroin. The silkworm is killed in its cocoon using steam or hot air so the silk filament isn't broken by the emerging moth.
3 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
How do silkworms produce silk?
Sericulture is the production of raw silk by raising silkworms, typically the domesticated silkworm (Bombyx mori). Silkworms are raised by feeding on mulberry leaves until they are ready to spin a cocoon.
The silkworm builds its cocoon using a long, continuous fiber secreted from glands, made of a protein called fibroin. This secretion emerges from a spinneret and hardens when exposed to air, forming twin filaments. A second pair of glands secretes sericin, a gummy substance that cements the two filaments together. The pupa is killed by steam or hot air. The silk filament is then unwound from the cocoon. Several filaments are combined and twisted to create silk yarn. This yarn is processed to remove sericin, leaving a soft, lustrous fiber that can then be dyed and woven into fabric.
3 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What are the main steps involved in silk production?
Sericulture, or silk production, involves raising silkworms to obtain raw silk. The process starts with caring for silkworms from the egg stage, feeding them mulberry leaves until they are ready to spin a cocoon. Silkworms secrete fibroin, a protein that hardens into a continuous filament when exposed to air, and sericin, a gummy substance that holds the filament together.
To prevent the emerging moth from breaking the cocoon, the silkworm is killed using steam or hot air. Next, the silk filament is unwound from the cocoon in a process called reeling. Several filaments are combined and twisted to create a strong strand of silk yarn. The raw silk is then processed to remove sericin, leaving a soft, lustrous fiber that is dyed and woven into fabric.
2 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
Why is mulberry important in sericulture?
Mulberry leaves are essential to sericulture because they are the primary food source for silkworms, specifically the Bombyx mori, during their larval stage. Silkworms feed on mulberry leaves until they are ready to spin a cocoon. The health and growth of the silkworms, and thus the quality and quantity of silk produced, are directly dependent on the availability and nutritional value of mulberry leaves. Several species of mulberry are cultivated for silkworms, with the white mulberry being the most popular.
4 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
How does sericulture impact local economies and communities?
Sericulture, or silk production, significantly boosts local economies and communities through the cultivation of mulberry trees for silkworm rearing and cocoon production. This practice creates jobs in rural areas, from silkworm rearing to silk reeling and yarn production. Additionally, silk processing generates income through spinning, throwing, and weaving, supporting local artisans and industries. The final raw silk product is valued for its strength, luster, and ability to be dyed, which enhances its marketability and economic impact in local communities.
1 Britannica SourceCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
sericulture, the production of raw silk by means of raising caterpillars (larvae), particularly those of the domesticated silkworm (Bombyx mori).
The production of silk generally involves two processes:
- Care of the silkworm from the egg stage through completion of the cocoon.
- Production of mulberry trees that provide leaves upon which the worms feed.
The silkworm caterpillar builds its cocoon by producing and surrounding itself with a long, continuous fibre, or filament. Liquid secretions from two large glands within the insect emerge from the spinneret, a single exit tube in the head, hardening upon exposure to air and forming twin filaments composed of fibroin, a protein material. A second pair of glands secretes sericin, a gummy substance that cements the two filaments together. Because an emerging moth would break the cocoon filament, the larva is killed in the cocoon by steam or hot air at the chrysalis stage.
" height="20" alt="HEW Logo">
Silk is a continuous filament within each cocoon, having a usable length of about 600 to 900 metres (2,000 to 3,000 feet). It is freed by softening the binding sericin and then locating the filament end and unwinding, or reeling, the filaments from several cocoons at the same time, sometimes with a slight twist, forming a single strand. Several silk strands, each too thin for most uses, are twisted together to make thicker, stronger yarn in the process called throwing, producing various yarns differing according to the amount and direction of the twist imparted.
Silk containing sericin is called raw silk. The gummy substance, affording protection during processing, is usually retained until the yarn or fabric stage and is removed by boiling the silk in soap and water, leaving it soft and lustrous, with weight reduced by as much as 30 percent. Spun silk is made from short lengths obtained from damaged cocoons or broken off during processing, twisted together to make yarn. The thickness of silk filament yarn is expressed in terms of denier, the number of grams of weight per 9,000 metres (9,846 yards) of length. Silk is sometimes—in a process called weighting—treated with a finishing substance, such as metallic salts, to increase weight, add density, and improve draping quality.
The degumming process leaves silk lustrous and semitransparent, with a smooth surface that does not readily retain soil. Silk has good strength, resisting breakage when subjected to weights of about 4 grams (0.5 ounce) per denier. Wetting reduces strength by about 15–25 percent. A silk filament can be stretched about 20 percent beyond its original length before breaking but does not immediately resume its original length when stretched more than about 2 percent. Silk, lower in density than such fibres as cotton, wool, and rayon, is moisture-absorbent, retaining as much as a third of its weight in moisture without feeling damp, and has excellent dyeing properties. It is more heat-resistant than wool, decomposing at about 170° C (340° F). Silk loses strength over a long period of time without appropriate storage conditions and tends to decompose with extensive exposure to sunlight but is rarely attacked by mildew. It is not harmed by mild alkaline solutions and common dry-cleaning solvents. Friction imparts a static charge, especially in low humidity. The rustling sound, or scroop, associated with crisp silk fabrics is not a natural property of the fibre but is developed by processing treatments, and it does not indicate quality, as is sometimes believed.
There has long been interest in devising ways to produce silk that is stronger and more elastic than that produced by silkworms or traditional sericulture methods. One approach has involved the introduction of spider silk genes into the silkworm genome; spider silk is known for its remarkable strength and elasticity, but it cannot be mass produced by farming spiders. Genetically modified silkworms spin a strong composite silk that has many potential applications.
The trusted destination for professionals, college students, and lifelong learners.
SUBSCRIBE
