What kind of caterpillar is this?

Asked October 15, 2013, 1:36 PM EDT

Can you tell what this is? It was found in the compost pile. Note how large it is compared to the adult hand.

Montgomery County Maryland

1 Response

Your caterpillar is obviously that of a Sphinx moth, but the exact species is difficult to determine. Since you found it in the compost pile and given the season, it was likely seeking a place to pupate. As caterpillars mature and begin the process of pupation, their colors will intensify or change, sometimes dramatically. As we searched for a likely identification of your caterpillar we considered the possibility that it is a 'White- lined' Sphinx, There are several other realistic possibilities.
LS