The Collaborative International Dictionary of English v.0.48:

Polyphemus \Pol`y*phe"mus\, n. [L. Polyphemus the one-eyed
   Cyclops who was blinded by Ulysses.] (Zool.)
   A very large American moth (Telea polyphemus) belonging to
   the Silkworm family (Bombycid[ae]). Its larva, which is
   very large, bright green, with silvery tubercles, and with
   oblique white stripes on the sides, feeds on the oak,
   chestnut, willow, cherry, apple, and other trees. It produces
   a large amount of strong silk. Called also American
   silkworm.
   [1913 Webster]