Source : Webster's Revised Unabridged Dictionary (1913)

Isabella moth \Is`a*bel"la moth`\ (?; 115). (Zo["o]l.)
   A common American moth ({Pyrrharctia isabella}), of an
   isabella color. The larva, called {woolly bear} and {hedgehog
   caterpillar}, is densely covered with hairs, which are black
   at each end of the body, and red in the middle part.