Silk worms spin their cocoon during the pupa stage

Silk worms are the larvae of the silk moth. They belong to the family of Bombycidae and are known for their ability to spin silk. The process of silk production begins when the silk worm starts to spin its cocoon during the pupa stage. Let's explore this process in detail.

The Pupa Stage
The pupa stage is the third stage in the life cycle of a silk worm. During this stage, the larva undergoes a metamorphosis and transforms into an adult silk moth. The pupa stage lasts for around 10-14 days, and it is during this time that the silk worm starts to spin its cocoon.

Cocoon Spinning Process
The silk worm spins its cocoon using a gland in its body that produces a liquid protein called fibroin. The silk worm secretes this liquid protein through two small openings located near its mouth called spinnerets. The fibroin then solidifies when it comes into contact with the air, forming a long, continuous silk strand.

The silk worm then wraps this silk strand around its body in a figure-eight pattern, forming its cocoon. The cocoon provides protection to the pupa during its transformation into an adult moth.

Harvesting Silk
Once the silk worm has finished spinning its cocoon, the cocoon is harvested to obtain the silk. To harvest the silk, the cocoon is boiled in water to kill the silk worm and loosen the silk strands. The silk strands are then unwound from the cocoon and spun into thread, which can be used to make textiles, clothing, and other products.

In conclusion, silk worms spin their cocoon during the pupa stage using a liquid protein called fibroin. The cocoon provides protection to the pupa during its transformation into an adult moth. The silk from the cocoon is obtained through a process of boiling and unwinding the cocoon to obtain the silk strands.

'Larva stage' of a Silk moth's lifecycle