 The subspecies of the ailanthus silkmoth, "Samia cynthia ricini", eat the leaves of the castor bean or cassava leaves.It is also known as the eri silkmoth.Eri silk is made from the cocoons of these particular insects and is also produced using less violent methods than the normal heat treating, but the quality of Eri silk is often seen as inferior to that of the silk created by the offspring of the "Bombyx mori" moth.