We found this caterpillar crossing a trail towards the bottom of Mount Megunticook in Camden, Maine. It was quite large (approx 3-4 inches) and fat. We’ve searched for it on numerous web sites and can’t seem to identify it. Can you help?
From the size of the caterpillar and the dark head I am going to guess this is a Polyphemus caterpillar.
The photo is not clear enough to be sure, but there are not many caterpillars that size with those characteristics.
This is one of the large silkworm moths – family Saturniidae.
The dark coloration would mean that it is heading to pupate. The cocoons are either spun on the tree of the host plant or in leaf litter under the tree. Perhaps in ME it is time to overwinter as a cocoon.
The larva feed on many deciduous trees and shrubs including oak, as well as birch, hickory, maple, willow, grape and roses. Moths do not feed.
This insect is found thru out North America except Newfoundland. It is a very common Saturniid moth.