Eri Silk is often referred to as Peace Silk. This is because it is spun rather than reeled, due to the way the silkworm makes the cocoon*. Technically it’s possible to spin the silk without stifling (i.e. killing) the pupa, hence it is a “peaceful” way to harvest silk. True Peace Silk is called “Ahimsa Silk”, which is a Sanskrit word meaning “without injury or harm”.
Is Eri Silk actually harvested without stifling the pupa? Rarely. In other words, there is very little Ahimsa silk produced, and what there is is very expensive. In the countries that grow Eri silk, often in poorer rural areas, the pupae are a valuable protein source in the peoples’ diets. It is high quality, inexpensive, and easy to produce. (This is also true of other species of silk, where the cocoon is harvested.) Without this protein source, people would need to raise other forms of protein, often with greater detriment to the ecology and environment. Often economically disadvantaged silk producers earn more from the protein-rich pupae than from the silk.
In fact, Eri silk is like virtually all food crops – only enough of the live cocoons are kept to produce the next generation. They’re the “seed providers” for the next crop.
Another important part of the silk life cycle story is that the moth, if allowed to emerge, does not have the ability to eat; it doesn’t have the necessary digestive parts. Its sole purpose is to mate and lay eggs before dying. The moth rarely lives more than 3 or 4 days. The entire life cycle, from hatching to natural death, is about 8 weeks, with the moth representing 4 days of that time.
*The Eri silkworm spins a cocoon with a hole at one end. It also spins intermittently rather than continuously. The result is that Eri silk cocoons have many shorter filaments rather than one long, continuous one.