🐛 Types of Silkworms and Silk Varieties

In the previous lesson, we introduced sericulture -- its definition, India's global position, and why the silk industry matters for rural livelihoods. Now we examine the five types of silkworms reared in India, each producing a distinct variety of silk.

In Assam, a farmer rears Muga silkworms on Som trees to produce the world-famous golden-yellow silk for traditional mekhela chadors. In Jharkhand, tribal communities rear Tasar silkworms on Sal and Arjun trees in the open forest for the distinctive copper-brown Tussar silk. Meanwhile, in Karnataka, millions of Mulberry silkworms are fed on fresh mulberry leaves indoors, producing over 40% of India's total silk. Each type of silk comes from a different silkworm species with unique biology, host plants, and rearing methods.

This lesson covers:

1. Five silkworm types -- Mulberry, Tropical Tasar, Oak Tasar, Muga, Eri
2. Host plants, voltinism, and silk characteristics for each
3. Classification by occurrence and generations per year
4. Silkworm morphology basics

Quick Differentiation Rule

Master Comparison of Five Silkworm Types

1. Mulberry Silk -- Bombyx mori

• Family: Bombycidae, Lepidoptera. The most thoroughly domesticated insect after the honeybee -- selectively bred for over 5,000 years; cannot survive in the wild.
• Feeds exclusively on mulberry leaves (Morus alba) -- monophagous. Cultivation of mulberry is called moriculture.
• Accounts for the bulk of world commercial silk -- often, "silk" simply refers to mulberry silk.
• Major Indian states: Karnataka (>40%), Andhra Pradesh, Tamil Nadu, West Bengal, J&K (together = 92% of India's mulberry silk).
• Native to northern China; imported to India centuries ago.
• Five larval instars (four moults -- hence called tetramoulters).
• Optimum growth: 20-28 C, 70-85% RH.
• Female pupa has an 'X' mark on the 8th abdominal segment (used for sex sorting).
• Herold's gland present in females between 8th and 9th segments.

2. Tropical Tasar Silk -- Antheraea mylitta

• Family: Saturniidae, Lepidoptera. A wild silkworm reared in open forests on host trees.
• Host plants: Asan (Terminalia tomentosa), Arjun (Terminalia arjuna), Sal (Shorea robusta), Ber (Zizyphus jujuba).
• Bivoltine (two generations per year).
• Produces copper-brown, coarse silk -- used mainly for furnishings and interiors. Less lustrous than mulberry but has its own distinctive appeal. The natural colour comes from tannins in host plant leaves.
• Larva spins a ring-like structure and a peduncle (silk stalk) attaching the cocoon to the twig -- a unique feature.
• Main states: Jharkhand, Chhattisgarh, Odisha, Maharashtra, WB, AP (Central Indian tribal belt / Gondwana region).
• Mainstay livelihood for tribal communities. India is the exclusive producer of tropical tasar globally.

3. Oak Tasar Silk -- Antheraea proylei

• Family: Saturniidae. A finer variety of tasar feeding on oak trees in the sub-Himalayan belt.
• States: Manipur, Himachal Pradesh, UP, Assam, Meghalaya, J&K.
• China is the world's major producer (from Antheraea pernyi); India is the second-largest producer.
• Also called temperate tasar. Finer and lighter than tropical tasar -- suitable for fashion garments, dress materials, and sarees.

4. Muga Silk -- Antheraea assamensis

• Family: Saturniidae. A semi-domesticated, multivoltine silkworm (5-6 generations/year; 2-3 crops commercially harvested).
• The unique monopoly of India -- no other country produces muga silk.
• Assam accounts for more than 95% of production.
• Host plants: Som (Machilus bombycina) and Soalu (Litsaea polyantha) -- evergreen trees of the laurel family.
• Produces golden-yellow silk with a natural lustre that improves with each wash (a unique property).
• Commands the highest price among all Indian silks due to rarity and exceptional beauty.
• Deeply embedded in Assamese culture -- the traditional mekhela chador is made of muga silk for festivals and special occasions.

Explore More

• Muga silk production in Assam
• Golden silk of Assam -- Muga silkworm rearing

5. Eri Silk -- Philosamia ricini

• Family: Saturniidae (not Bombycidae -- this is an exam trap). Multivoltine, domesticated.
• Also known as: Endi, Errandi, or Arandi silk (from Hindi arandi = castor).
• Host plant: Castor leaves (Ricinus communis) and Kesseru (Heteropanax fragrans).
• Non-reelable silk -- the cocoon has an open end, so the moth can emerge without breaking the filament. This is why eri is called "Peace silk" or "Ahimsa silk" (the moth is not killed).
• Since the filament is discontinuous, eri silk is spun (like cotton or wool), giving it a soft, warm, cottony texture.
• In NE India, eri cocoons are produced primarily for their edible pupae (rich in protein) -- silk is the by-product. Dual use (food + fibre) makes eri uniquely valuable.
• Excellent thermal insulation -- ideal for winter shawls and chaddars. Can be blended with cotton, wool, jute, or mulberry silk.

Classification

By Occurrence

• Vanya sericulture was an exclusive craft of tribal and hill communities in Central and NE India, now gaining national importance due to global demand for eco-friendly, natural textiles.

By Voltinism (Generations per Year)

Silkworm Morphology

Summary Table

Quick Comparison: Which Silkworm for Which Region?

AFO advisory guide — recommending the right silkworm:

India is the ONLY country producing all 5 commercial silks. This is a guaranteed exam fact.

Summary Cheat Sheet