This photo is of a Polyphemus Moth Cocoon that I found on the forest floor while hiking. I see these often here in the Ouachita National Forest of Arkansas. I didn’t know what these were until I posted a photo of one on Facebook last year. Thanks to Bill Yox for educating me on what type of Moth creates these cocoons.
Polyphemus Moth Facts
It lays flat, light-brown eggs on the leaves of a number of host plants, including: Betula (birch), Salix (willow), Quercus (oak), Acer (maple), Carya (hickory), Fagus (beech), Gleditsia triacanthos (honey locust), Juglans (walnut), Pyrus (pear and quince), Prunus (plum, peach, apricot, cherry, etc.), Sassafras, Citrus, and Ulmus americana (American elm).
When the eggs hatch, small yellow caterpillars emerge. As the caterpillars age, they molt five times (the fifth being into a pupa). Each instar is slightly different, but on their fifth and final instar, they become a bright green color with silver spots on their sides. They feed heavily on their host plant and can grow up to 3–4 in long. They then spin cocoons of brown silk, usually wrapped in leaves of the host plant.
Two broods generally hatch each year throughout the United States, one in early spring and one in late summer.
Adults of this family of moths have vestigial mouths, meaning their mouth parts have been reduced. Because of this, they do not eat and only live as adults for less than one week. (Wikipedia)