Depending on needs and resources, silk yarn is an excellent fiber with which to work. Durable, lightweight, and extremely strong, silk has been used in a number of industries, from fishing lines to car tires. I often wonder if people would look at it differently if they knew it was a product of caterpillar spit. Yes, that’s right, caterpillar spit.
The Chinese silkworm (Bombyx mori) has been domesticated for thousands of years for the sole purpose of manufacturing silk. They have been domesticated for so long that they are no longer capable of living in the wild and have since gone extinct. But rest assured, the domestic variety shows no signs of going anywhere. The Chinese were the first to domesticate the silkworm, and silk became an important feature of the Chinese economy early on, leading to the now famous silk road, which carried the fiber all the way to Rome. Silk was at one time as ubiquitous as nylon and cotton are today. Everyone wore it. Thus the Chinese were always very protective of silk production, and smuggling silkworms out of China carried the death penalty at one time. Eventually, one way or another, they made their way out of China and are now raised on virtually every continent. After going out of style briefly upon the advent of synthetic fibers, silk is coming back in, often mixed with other fibers. (Check out http://www.knitpicks.com/yarns/Gloss_DK_Yarn__D5420190.html )
The silkworm is, of course, the larval form of the silkmoth. After gorging themselves on mulberry leaves for about six weeks, the two inch long silkworms spin a cocoon of silk around themselves, which is then steamed to collect the silk. Yes, they are steamed while the pupa is still inside. They did not die in vain. The cocoons can yield up to a half mile of silk fiber!
The cocoons that are not steamed are allowed to metamorphose into medium sized white, fuzzy moths. The cocoons are still usable after the adults have emerged, but the fibers are significantly lower in quality. In order to emerge from the cocoon, the adults secrete an enzyme that partially dissolves the fibers. They essentially have to eat their way out, and no one wants half-eaten silk.
The adults live for a few days, just long enough to mate and lay eggs, then they die. The eggs pass through a dormant period (they have to be kept cold) before hatching into tiny caterpillars and the process begins again.
Those brave enough are welcome to try raising silkworms themselves, I’m given to understand it’s fairly simple. This is a good website on the subject of raising silkworms.
**Opinions expressed on blogs about which I write are the opinion of the blog authors and DO NOT necessarily reflect my own opinion.