page_title: Bombyx mori
section_title: Process
hierarchical_section_title: Bombyx mori / Process
caption_attribution_description: English: Silkmoth or Bombyx mori
context_page_description: Bombyx mori, the domestic silk moth, is an insect from the moth family Bombycidae. It is the closest relative of Bombyx mandarina, the wild silk moth. The silkworm is the larva or caterpillar of a silk moth. It is an economically important insect, being a primary producer of silk. A silkworm's preferred food are white mulberry leaves, though they may eat other mulberry species and even the osage orange. Domestic silk moths are closely dependent on humans for reproduction, as a result of millennia of selective breeding. Wild silk moths are different from their domestic cousins as they have not been selectively bred; they are thus not as commercially viable in the production of silk.
  Sericulture, the practice of breeding silkworms for the production of raw silk, has been under way for at least 5,000 years in China, whence it spread to India, Korea, Nepal, Japan, and the West. The domestic silk moth was domesticated from the wild silk moth Bombyx mandarina, which has a range from northern India to northern China, Korea, Japan, and the far eastern regions of Russia. The domestic silk moth derives from Chinese rather than Japanese or Korean stock.
context_section_description: Eggs take about 14 days to hatch into larvae, which eat continuously. They have a preference for white mulberry, having an attraction to the mulberry odorant cis-jasmone. They are not monophagous, since they can eat other species of Morus, as well as some other Moraceae, mostly Osage orange. They are covered with tiny black hairs. When the color of their heads turns darker, it indicates they are about to molt. After molting, the larval phase of the silkworms emerge white, naked, and with little horns on their backs.
  After they have molted four times, their bodies become slightly yellow, and the skin becomes tighter. The larvae then prepare to enter the pupal phase of their lifecycle, and enclose themselves in a cocoon made up of raw silk produced by the salivary glands. The final molt from larva to pupa takes place within the cocoon, which provides a vital layer of protection during the vulnerable, almost motionless pupal state. Many other Lepidoptera produce cocoons, but only a few—the Bombycidae, in particular the genus Bombyx, and the Saturniidae, in particular the genus Antheraea—have been exploited for fabric production.
  If the animal is allowed to survive after spinning its cocoon and through the pupal phase of its lifecycle, it releases proteolytic enzymes to make a hole in the cocoon so it can emerge as an adult moth. These enzymes are destructive to the silk and can cause the silk fibers to break down from over a mile in length to segments of random length, which seriously reduces the value of the silk threads, but not silk cocoons used as "stuffing" available in China and elsewhere for doonas, jackets, etc. To prevent this, silkworm cocoons are boiled. The heat kills the silkworms and the water makes the cocoons easier to unravel. Often, the silkworm itself is eaten.
  As the process of harvesting the silk from the cocoon kills the larva, sericulture has been criticized by animal welfare and rights activists. Mahatma Gandhi was critical of silk production based on the Ahimsa philosophy "not to hurt any living thing". This led to Gandhi's promotion of cotton spinning machines, an example of which can be seen at the Gandhi Institute. He also promoted Ahimsa silk, wild silk made from the cocoons of wild and semiwild silk moths.
  The moth – the adult phase of the lifecycle – is not capable of functional flight, in contrast to the wild B. mandarina and other Bombyx species, whose males fly to meet females and for evasion from predators. Some may emerge with the ability to lift off and stay airborne, but sustained flight cannot be achieved. This is because their bodies are too big and heavy for their small wings. However, some silk moths can still fly. Silk moths have a wingspan of 3–5 cm (1.2–2.0 in) and a white, hairy body. Females are about two to three times bulkier than males (for they are carrying many eggs), but are similarly colored. Adult Bombycidae have reduced mouthparts and do not feed, though a human caretaker can feed them.
caption: Wild silk moth Bombyx mandarina
exif: {"Image Copyright": "Ash Bowie Photography"}