ABSTRACT
Harvesting Silk Thread The process of cultivating and making silk, called sericulture, has changed very little over the centuries. The silkworm feeds only on the leaves of particular types of mulberry tree, and no successful substitute for this food has ever been found. A single moth lays 300-400 eggs at a time, each about the size of a pinhead. The eggs hatch after ten days and the larva are about half an inch (1.25 centimeters) long. They are carefully protected in specially made trays stacked one on top of another, and the temperature is closely watched. They are fed huge quantities of mulberry leaves for the next 35 days until they are many thousands of times heavier than when they hatched. When they reach a certain size they naturally begin to spin themselves cocoons from spinnerets in their heads. It takes them two to four days to finish the cocoon, which is made of a single thread up to 3,000 feet (915 meters) long. II left alone, the pupae inside the cocoon begin to give off a chemical that 'melts' the cocoon so it can escape when it becomes a moth. A few are left to do this so that there will he a new generation of moths to lay eggs, but most are killed inside the cocoon at this point using heat. Just as in the legend of Leizu, the cocoons must then be soaked in hot water to loosen the end of the thread. The cocoon is unraveled into one long continuous strand and several of these are then twisted together to make a thread strong enough 10 use for weaving and embrOidery.
