August 5, 2012 4:54 pm
I was sitting outside today and felt something touch my foot, looked down to see a very large (3-4 inches long) fleshy and green colored caterpillar (hornworm maybe?) It had a horn looking thing on the butt end. I had never seen one of these here in Idaho where I live. I tried looking it up online, but with no results. Can you help me identify this?
After first writing back to you to agree that this was a Hornworm and to inform you that we did not recognize the species, we decided to attempt an identification. There are not many species of Sphinx Moths recorded in Idaho according the Sphingidae of the Americas website, so we quickly identified this as a prepupal Poplar Sphinx Caterpillar, Pachysphinx modesta, on the Sphingidae of the United States website.