Exploring Non-Mulberry Silkworms: Muga, Eri, and Tasar

India is home to three remarkable non-mulberry silkworms – muga (Antheraea assamensis), eri (Samia ricini), and tasar (Antheraea mylitta) – that together form the backbone of the country’s wild silk industry. Unlike the domesticated mulberry silkworm (Bombyx mori), these insects are adapted to natural forest environments, feeding on diverse host plants and producing silk with textures, colors, and properties that mulberry silk simply cannot replicate. Each species has its own lifecycle, geographical range, and cultural legacy – and understanding them is essential for anyone studying sericulture or sustainable textile production.

What makes non-mulberry silkworms different?
Muga silkworm (Antheraea assamensis): the golden silk producer
Host plants and semi-domesticated rearing
Lifecycle of the muga silkworm
Eri silkworm (Samia ricini): the peace silk maker
Host plants and domestication
Lifecycle of the eri silkworm
Tasar silkworm (Antheraea mylitta): silk from the forest floor
Host plants and wild rearing
Lifecycle of the tasar silkworm
Comparing the three species: key differences at a glance

What makes non-mulberry silkworms different?

Most commercial silk worldwide comes from Bombyx mori, which is fully domesticated, reared indoors, and fed exclusively on mulberry leaves. Non-mulberry silkworms take a very different path. They belong to the family Saturniidae – large, robust moths that have evolved over millennia to survive outdoors, often in semi-wild or completely wild conditions. Their silk fibers are coarser, stronger, and naturally colored, making them distinct in both appearance and application. According to the Shivaji College academic material on non-mulberry sericulture, these insects are cultivated in places where their specific host plants are naturally available, which means production is inherently tied to the local forest ecosystem.

Muga silkworm (Antheraea assamensis): the golden silk producer

Muga silk is often called the world’s most luxurious wild silk, and with good reason. The muga silkworm is endemic to Assam and the adjoining areas of northeast India, where nearly 99% of global muga production occurs. The silk it produces has a distinctive natural golden sheen that actually intensifies with age and washing – a quality so exceptional that the silk is almost never dyed.

Host plants and semi-domesticated rearing

Muga larvae feed primarily on som (Persea bombycina) and soalu (Litsea monopetala), two plants from the laurel family that grow naturally in Assam’s humid climate. They can also feed on other laurel-family plants including species of Cinnamomum, Machilus, and Actinodaphne. Unlike mulberry silkworms, muga silkworms are semi-domesticated – meaning they are reared on naturally growing host plants, not under fully controlled indoor conditions. Rearers build protective enclosures around the host trees to shield caterpillars from birds and predators while maintaining a largely natural environment. This approach requires deep local ecological knowledge and makes muga culture inseparable from Assam’s forest landscape.

Lifecycle of the muga silkworm

The muga silkworm undergoes complete metamorphosis through four stages: egg, larva, pupa, and adult moth. According to detailed lifecycle studies, the female moth lays 150-200 oval-shaped, pale-yellow eggs on som and soalu leaves. These eggs hatch in 9-12 days. The larval stage is the most extended phase, lasting around 30-35 days, during which larvae pass through five molting stages (instars). After completing larval development, the caterpillar spins a cocoon and enters the pupal stage before emerging as an adult moth.

What makes the muga silkworm particularly valuable commercially is its multivoltine nature – it produces 5 to 6 generations per year. As confirmed by the Government of Assam’s Directorate of Sericulture, farmers typically harvest crops across distinct seasonal cycles: the commercially important Jethua crop (May-June), Kotia crop (October-November), and several pre-seed crops through the year. This continuous production calendar makes muga sericulture a year-round livelihood activity for communities in Assam and East Garo Hills of Meghalaya.

Eri silkworm (Samia ricini): the peace silk maker

The eri silkworm holds a unique ethical distinction in the world of silk – it is the primary source of ahimsa silk, also known as peace silk. This is because the eri cocoon is open at one end, allowing the adult moth to emerge naturally before the cocoon is processed. As a result, eri silk production does not require killing the pupa, unlike conventional silk processing where cocoons are boiled with the larva inside to preserve fiber continuity. This makes it popular among vegan and Buddhist communities, and among consumers in countries like Japan and South Korea who prefer cruelty-free textiles.

Host plants and domestication

Eri is the most domesticated among the three non-mulberry silkworms, having been selectively bred for centuries, primarily in the Brahmaputra Valley of Assam. Its primary host plant is castor (Ricinus communis), whose leaves are rich in protein – with up to 26% dry matter content – supporting rapid larval growth and high silk yield. In Assam, the castor plant is locally called “Era,” which is where the name “Eri silk” originates. As a polyphagous species, it can also feed on tapioca (Manihot esculenta), papaya, and kesseru (Heteropanax fragrans), giving it a flexibility that makes rearing accessible across varied agro-climatic zones. Northeastern states account for nearly 98% of India’s eri silk output.

Lifecycle of the eri silkworm

The eri lifecycle follows the same four-stage pattern – egg, larva, pupa, and adult moth. The female lays clusters of 300-500 eggs, which incubate for 10-12 days under optimal conditions of 24-26°C and 75-80% relative humidity. The larval stage, where the worm passes through five instars, lasts approximately 24-28 days when reared on castor leaves. During this phase, mature fifth-instar larvae can consume 500-750 grams of castor leaves per day, marking a dramatic growth phase – the larva increases to roughly 12 times its hatching size by the time it is ready to spin. Cocoon spinning takes about 3-5 days. After the moth emerges from the open end, the cocoon is harvested and processed through spinning rather than reeling, producing a staple fiber with a texture closer to wool than conventional silk.

Eri is multivoltine, capable of producing 3-6 generations per year depending on climate and day-length. Because it does not go through diapause – a dormant phase triggered by seasonal cues – eri rearing can continue year-round with consistent management of food supply. The primary rearing season runs from March to August, when castor plants are most abundant and warm, humid conditions accelerate development.

Tasar silkworm (Antheraea mylitta): silk from the forest floor

Tasar silk is the most forest-dependent of the three wild silks, and the one most closely tied to India’s tribal communities. The tasar silkworm (Antheraea mylitta) lives and feeds in the deciduous forests of central and eastern India – primarily in the states of Jharkhand, Chhattisgarh, Odisha, Andhra Pradesh, and West Bengal. Tasar sericulture is mainly practiced by rural and tribal communities, for whom it represents both a cultural tradition and a critical source of income.

Host plants and wild rearing

Tasar silkworms are polyphagous, capable of feeding on over 51 plant species, but they perform best on three primary hosts: arjun (Terminalia arjuna), asan (Terminalia tomentosa), and sal (Shorea robusta). As documented in a 2025 bibliometric study in Frontiers in Insect Science, tasar production is deeply intertwined with forest ecosystems, making the industry environmentally sustainable by design. Since larvae are reared outdoors on actual trees, tasar sericulture preserves forest cover and supports biodiversity simultaneously. The availability of host trees like Terminalia arjuna and T. tomentosa is a direct determinant of rearing viability, and deforestation is one of the primary threats to the industry.

Lifecycle of the tasar silkworm

Like the other non-mulberry species, tasar undergoes holometabolous (complete) metamorphosis – egg, larva, pupa, and adult moth. The female moth is large, yellowish-brown in color, while males are smaller with brick-red wings. Adults have wingspans of about 15 cm, making them among the largest silk moths in India. After mating, females lay eggs on host tree leaves. Larvae progress through five instars, feeding voraciously and eventually entering a wandering phase before they select a suitable site to spin their cocoon. Cocoon formation takes approximately two days, during which the larva weaves silk in a figure-of-eight motion, attaching the cocoon via a silk stalk or peduncle to a leaf petiole or tree twig.

Voltinism in tasar varies by ecorace. India recognizes at least 44 ecoraces of A. mylitta, distributed across different forest and agro-climatic zones. Depending on biotic and abiotic conditions, a tasar silkworm completes its lifecycle two to three times per year. The Daba ecorace – the most commercially exploited – is bivoltine or trivoltine, while some ecoraces are strictly univoltine. This strong seasonal dependence means tasar production schedules are closely tied to monsoon patterns and the leaf flush cycles of deciduous host trees.

Comparing the three species: key differences at a glance

The three species differ significantly in degree of domestication, host plant specificity, silk characteristics, and lifecycle duration. Muga is semi-domesticated and confined almost entirely to Assam, producing a highly valued golden silk that improves with age. Eri is the only fully domesticated non-mulberry silkworm, adaptable to indoor rearing and multiple host plants, and unique for its open-ended cocoon structure that enables ahimsa silk. Tasar is the most wild of the three – reared entirely outdoors in forest settings – and produces a coarse, golden-brown silk that accounts for a significant share of India’s total wild silk output. Eri silk alone made up 73% of India’s total wild silk production in a recent survey period, reflecting how broadly accessible its rearing has become compared to the more geographically restricted muga and forest-dependent tasar.

All three silkworms are critical to India’s rural economy – not just as silk producers, but as anchors of cultural identity and sustainable livelihoods. The Central Silk Board, under India’s Ministry of Textiles, actively supports research and development for all three species, recognizing their ecological and economic significance for tribal and farming communities across the country.

What do you think? With growing global interest in sustainable and cruelty-free textiles, could non-mulberry silks like eri and muga find a larger share in mainstream fashion markets? And given how closely tasar sericulture depends on intact forest ecosystems, what role should conservation policy play in protecting India’s wild silk heritage?

How useful was this post?

Click on a star to rate it!

Average rating 0 / 5. Vote count: 0

No votes so far! Be the first to rate this post.

References

PDF 📄

Table of Contents

What makes non-mulberry silkworms different? 🔗

Muga silkworm (Antheraea assamensis): the golden silk producer 🔗

Host plants and semi-domesticated rearing 🔗

Lifecycle of the muga silkworm 🔗

Eri silkworm (Samia ricini): the peace silk maker 🔗

Host plants and domestication 🔗

Lifecycle of the eri silkworm 🔗

Tasar silkworm (Antheraea mylitta): silk from the forest floor 🔗

Host plants and wild rearing 🔗

Lifecycle of the tasar silkworm 🔗

Comparing the three species: key differences at a glance 🔗