Patna, Jan 14 (IANS): This year's harsh winter has badly hit production of the famous tussar silk in Bihar's Bhagalpur and adjoining districts.

The production of tussar silk, popularly known as Bhagalpur silk, has slowed down because silkworms produce less silk in extreme cold, a Bhagalpur district official told IANS on phone.

In normal weather, the life span of tussar silkworms is between 28 and 35 days. But in winter, their life span goes up; they consume more leaves and produce less silk.

Last Thursday, Sabour in Bhagalpur was the coldest place in Bihar at 1.5 degrees Celsius.

According to experts, a cocoon produces about a gram of tussar silk in normal weather. But the quantity falls to .08 gram in winter.

The silk worm, during its life cycle, rotates its body in the form of figure eight some 300,000 times to construct a cocoon that generates nearly a kilometre of silk filament. After processing, it is fabricated into yarn, say experts.

Tussar silkworms live in the wild in trees belonging to Terminalia species and Shorea robusta as well as other food plants found in Bhagalpur, Banka, Munger and Jamui districts.

Hundreds of farmers engaged in keeping tussar silkworms on trees such as arjuna and asan are also facing a tough time in the cold. They are struggling hard to protect the leaves.

Until a few decades ago, silk manufacturing was a booming business in Bhagalpur, but it has lost to new centres in Bangalore and Ahmedabad.

Bhagalpur district, which was on the ancient Silk Route that connected India to China and Europe, supplies its silk to export houses in Kolkata, Delhi and Varanasi.