Silkworms are small insects that play a big role in making silk. They are most commonly found in farms where silk is produced, a practice called sericulture. Even though they look like ordinary caterpillars, silkworms go through an amazing life cycle that helps create one of the most valuable natural fibers in the world i.e. silk. In this article, you’ll learn about the different stages of a silkworm’s life and how each stage is important for silk production.

Stages and Duration of the Silkworm Life Cycle

When a female silk moth lays eggs, the life cycle of a silkworm officially begins. The silk thread (yarn) is taken from the cocoon of the silk moth after the cycle is complete. The silkworm’s life cycle lasts six to eight weeks. In general, the silkworm will finish its life cycle more quickly in warmer climates, but other elements like humidity and sunshine exposure are also quite significant. Ideal conditions for silkworms include 12 hours of daylight and 12 hours of darkness each day, a temperature of 23–28°C, and humidity levels of 85–90%. The eggs should hatch in 7–10 days under these circumstances.

All the stages of a silkworm’s life cycle are discussed in the section below:

Stage 1: Egg

The life cycle of a silkworm begins with the egg. It takes roughly 10 to 25 days to finish this stage. Over 350 eggs, each about the size of a dot, are laid by a female butterfly in one sitting. The eggs finally hatch once a year in the spring because of the warmer weather.

Stage 2: Larva/Cocoon

The silkworm senses the urge to cocoon after 20–33 days of non-stop feasting on Mulberry leaves. The human eye can distinguish ready-to-cocoon larvae because they are transparent and yellow in colour. The Silkworm releases a runny fluid just before it starts to cocoon in order to clear its system and get ready for the next phase of its life cycle. Then, it moves the head back and forth and oozes a little drop of silk to serve as an anchor before drawing one long, continuous string of silk. The silkworm can take up to 48 hours to finish this process, and the end product is an exquisitely oval cocoon. Around one-kilometre long silk-fibre strand can be produced from one cocoon of the silkworm.

Stage 3: Pupa

The pupa stage is the third stage of a silkworm’s life cycle. It is well known that the procedure is entirely immobile. The pupa is killed when the fully grown cocoon is dropped into boiling water. The silk strand is unrolled from the pupa for commercial use.

Stage 4: Moth

The Silk Moth emerges from its cocoon after 10 to 14 days of transformation into a moth, excreting a brownish substance. The final stage involves the development of a pupa into an adult moth. The female moth reproduces by laying eggs. The entire life cycle restarts following this stage.

The processing of silk is a crucial activity carried out after the silkworm’s life cycle is complete. “Silk processing” refers to a technique for extracting silk from the cocoon. The silk thread is usually released from the cocoon using sunlight. Once silk reeling is finished, the silk thread is unwound from the cocoon. The silk threads that are removed from cocoons are bleached. After the silk has been bleached, the fibre is spun into threads. The silk threads are further stacked to make the silk yarn. From the cocoons of the silk moths, silk is harvested in this manner.

Importance of Silkworm Life Cycle in Silk Industry

• Each stage is carefully managed to produce high quality silk
• Eggs are collected and stored safely to ensure healthy hatching
• Larvae are fed fresh mulberry leaves to help them grow strong and spin good cocoons
• Cocoons are the main source of silk, so their size and quality matter a lot
• Moths are allowed to mate and lay eggs, so the cycle continues for the next silk harvest
• Farmers monitor temperature and humidity to create the best conditions for silkworm growth
• Silk factories rely on the timing of each stage to plan harvesting and thread extraction properly

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