Samia cynthia, the ailanthus silkmoth, is a saturniid moth, used to produce silk fabric but not as domesticated as the silkworm, Bombyx mori.

The eri silk worm is the only completely domesticated silkworm other than Bombyx mori.

The silk is extremely durable, but cannot be easily reeled off the cocoon and is thus spun like cotton or wool.

[1] Peigler & Naumann (2003),[2] in their revision of the genus Samia, listed material of true Samia cynthia examined as follows: These include moths that have escaped from cultivation or were introduced and naturalized: Whitish eggs, marked with brown, are laid in rows of 10 to 20 on leaves in crescents.

Later instars are solitary, and whitish green with white tubercules along the back, and small black dots.