About Domestic Silkworms
A life raised on mulberry leaves, close to people, leaving behind the cocoon that becomes silk.
The domestic silkworm moves from egg to larva, pupa, and moth within about 50 to 60 days.
The climax of that short life is cocoon-making.
From that point, the materials that continue into reeled silk, mawata, and hand-spun yarn begin to emerge.
The domestic silkworm moves from egg to larva, pupa, and moth within about two months. The climax of that short life is cocoon-making, where silk begins.
Life Cycle
Just after hatching, the silkworm begins as a tiny dark larva, known in Japanese as gisan.
It feeds on mulberry leaves and passes through four molts. By the final fifth instar, it grows rapidly, eating most of the mulberry leaves it will consume in its lifetime.
When it reaches maturity, it climbs onto the mountage and spends two to three days making its cocoon.
Inside the cocoon it becomes a pupa, and then a moth, continuing on toward the next generation of life.
From the tiny dark gisan stage to the cocoon, this short cycle is both delicate and intense. By the final larval stage, most of the mulberry leaves it will ever eat are consumed.
The Growth of the Silk Gland
Inside the larva there is a pair of silk glands.
During the fifth instar, these develop rapidly, and by the time the silkworm is fully mature, a large part of its body is filled with what will soon become thread.
From the outside, the silkworm appears quiet.
But inside, the preparation for cocoon-making is gathering. When you think of that time, the cocoon begins to seem less like a shell and more like the final work left behind by a life.
Inside the larva, the silk gland grows rapidly during the final stage. The body gradually fills with what will soon become thread.
Threads Born from the Cocoon
Reeled Silk
A long filament drawn from a good single cocoon.
Smooth and even, it becomes one of the foundations of silk weaving.
Dupion Silk
A silk born from a double cocoon.
It carries a more irregular surface with slubs and a character of its own.
Spun Silk
A yarn spun from broken fibers and imperfect cocoons.
Balanced and practical, with a different kind of regularity.
Mawata to Tsumugi Yarn
A yarn made by softening the cocoon into mawata and spinning it by hand.
It carries fullness, warmth, and one of the essential textures of yamamayu cloth.
A cocoon does not end in a single form.
It separates into different kinds of thread, each carrying its own expression.
At yamamayu, those differences are kept alive and led onward into cloth.
One cocoon does not lead to only one kind of silk. Different parts and conditions of the cocoon become different kinds of thread, each with its own character.
Rearing Notes at yamamayu
Domestic silkworms are not only something to know through books.
When you actually raise them, their speed of growth and the density of their lives can be astonishing.
The studio has been leaving small records of that experience as well.
For those who would like to look more closely, there are also records of the first through fifth instars, and notes from a Koishimaru silk-reeling workshop.
Continue Reading
After following the life of the domestic silkworm, you may continue slowly into mawata, thread, and the cloth of the studio.
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山まゆの里染織工房 