The silk of the various species of Antheraea and Attacus is also thicker and stronger at the centre of the reeled portion than towards its extremities; but the diameter is much greater than that of common silk, and the filaments under the microscope (fig.
Fortunatus) and arracanensis, the Burmese worm - all of which yield several Antheraea pernyi (male).
The most important of the species at the present time is the Chinese tussur or tasar worm, Antheraea pernyi (figs.
Next in promising qualities is the muga or moonga worm of Assam, Antheraea assaina, a species to some extent domesticated in its native country.
The mezankoorie moth of the Assamese, Antheraea mezankooria, yields a valuable cocoon, as does also the Atlas moth, Attacus atlas, which has an omnivorous larva found throughout India, Ceylon, Burmah, China and Java.
Moonga silk from Antheraea assama has generally a rather darkbrown colour, but that appears to be much influenced by the leaves on which the worm feeds, the cocoons obtained on the champaca tree (Michelia champaca) giving a fine white fibre much valued in Assam.
Yama-mai worm of Japan, Antheraea (Sarnia) yama-mai, an oak-feeder, is a race of considerable importance in Japan, where it was said to be jealously guarded against foreigners.