Silkworms: Can You Stop Them From Spinning Silk?

The only time that silkworms do not produce silk is during the early life stages of this unique creature. Once they start spinning, there is no way to stop them. These valuable and amazing wonders can spin a cocoon that creates a silk thread measuring up to 600 meters (1,968 feet) in length.

While one single silkworm can create a silk thread measuring up to nearly 2,000 feet, it has to go through five instars or “stages” before it is ready to begin spinning this grand silk cocoon. In the first instar the silkworm caterpillars are black. In the second and third instars, they are grayish-white in color with black heads. In the fifth and final instar, the silkworm has a white head. In between each instar the silkworm rests and molts. In the fifth and final instar, the silkworm does 80% of it’s eating. At this point, the silk glands make up 25% of its body weight. It will take about a month for the silkworm caterpillar to grow big enough to spin a cocoon. The silkworm is ready to start spinning once it stops eating and turns a yellowish color. Just before they start spinning, the silkworm will make a wet, feces which helps rid its body of excess liquids. The cocoon-spinning process takes around three days to complete.

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Fun Facts About Silk Worms

The silkworm isn’t really a worm—it’s a caterpillar!

People have used the silkworm for over 4,000 years to make silk.

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The practice first began in China in about 2600 BC.

Outside of silk factories, silkworms are extinct. Silkworms are raised specificially for the silk threads they produce.

The practice of raising silkworms is called sericulture.

When fully grown, the silkworm reaches a length of about 5 to 7 centimeters (1.9-2.75 inches).

It takes about 25,000 cocoons to make half a kilogram of raw silk.

There are 600 silk weaving mills in China.

The vast majority of silk is produced in China and India. Roughly 60,000 tons of raw silk is made each year in these countries and a few others. In fact, there are 600 silk weaving mills in China.

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