AILANTHUS MOTH (Philosamia cynthia), a large silk spinning moth inhabiting China. The larvae feed on the leaves of the ailanthus tree and yield a silk more durable and cheaper than mulberry silk, but inferior to it in fineness and gloss. The moth measures about Sin. across, and is olive-brown in colour with a whitish spot and a white and purplish transverse bar on each wing. It was introduced with its food-tree into the eastern United States where it is now common.