The Other Silk Moths: Tussar, Eri and Muga

Bombyx mori Is Not the Only One

The silk in a shop is almost always mulberry silk from Bombyx mori. It is not the only silk, and the others come from different moths eating different trees. In South Asia these traditions developed alongside mulberry sericulture rather than being replaced by it.

Tussar

Produced by moths of the genus Antheraea. Tussar — also written tussah — is a wild or semi-wild silk, and the fibre is coarser and more textured than mulberry silk, with a natural colour rather than the near-white of Bombyx.

Eri

Produced by Samia. Eri silk is notable for how it is harvested: the moth is generally allowed to emerge from the cocoon before the silk is taken, which breaks the filament into shorter lengths and gives a spun, woollier yarn rather than a reeled continuous thread. It is sometimes called peace silk for that reason.

Muga

The most geographically specific of the three. Antheraea assamensis, produced exclusively in the Indian state of Assam, where the semi-domesticated moth feeds on Som and Soalu leaves rather than mulberry. Muga has a natural golden colour and is tied to one region in a way almost no other textile is.

Semi-Domesticated, Not Domesticated

The important contrast with Bombyx mori is not the fibre. It is the animal. These species are wild or semi-domesticated. They can fly, they can survive without people, and they are often reared outdoors on standing trees rather than in trays.

Mulberry silkworms cannot do any of that. Five thousand years of selection produced an animal that yields more silk and cannot live unattended — and the other silk moths are the control group that shows what was traded away.

Related: the silkworm's wild ancestor · what silk is made of