The Collaborative International Dictionary of English v.0.48:

Orgyia \Or*gy"i*a\, prop. n. [NL., fr. Gr. ? the length of the
   outstretched arms. So named because, when at rest, it
   stretches forward its fore legs like arms.] (Zool.).
   A genus of bombycid moths whose caterpillars (esp. those of
   Orgyia leucostigma) are often very injurious to fruit trees
   and shade trees. The female is wingless. Called also vaporer
   moth.
   [1913 Webster]