Orange-Red Caterpillar with horn
September 7, 2009
We found this in the yard today. I believe it is some type of Hornworm, but I can’t find any hornworms that are orange or red. It is currently munching on the leaf from an Ash tree.
Based on the food plant you indicated, we are guessing that this might be the caterpillar of the Northern Ash Sphinx, Sphinx chersis. It is an early instar, meaning its appearance can change greatly. Bill Oehlke’s Northern Ash Sphinx page does not show early instar larvae. We will copy Bill Oehlke on this response to see if he can clarify the species.
I think you might be correct! I look forward to Bill’s response.
Yes it is the ash sphinx which can be quite red or green in various instars. Edna Bottorff of Oregon, recently sent me images of earlier instars showing red and green forms and I will post them shortly.