A tale of two Saturniids

Actias luna (luna moth) caterpillar 

I typically don’t have very much luck finding caterpillars of the giant silk moths from the Saturnidae family. This past season was a little more successful. I found three polyphemus moth (Antheraea polyphemus) caterpillars and Sarah found the above luna moth caterpillar during our birthday hunting trip in mid-September. Larvae of these two species look very similar, but there are a few easy characteristics than can be used to distinguish between the two.

Antheraea polyphemus (polyphemus moth) caterpillar