The polyphemus moth is yellow-brown to red-brown and has an eyespot on each wing. Its wingspan is four to ﬁve inches. The feathery antennae are larger in the male than in the female. The large larva is green with a few spiny projections and dark markings.
The polyphemus moth may be found statewide in Illinois. The adult does not feed. The larva eats the leaves of trees and shrubs. The pupa is formed in a leaf on the ground, where it overwinters. One generation per year is produced.