Each year, one generation of this moth appears in North America. The larvae appear in late summer through early fall. The 40° north latitude demarks how many generations will appear. South of this line two or more generations can appear in a year. The adults will lay eggs on the underside of leaves in hair covered clusters of a few hundred eggs. It takes about a week for the eggs to hatch. The larval stage involves brightly and variably colored caterpillars. They range from pale yellow to dark gray. The fall webworm moth will have yellow spots, and both long and short bristles, giving them a fuzzy appearance. They also have two cream stripes along the side. The caterpillars grow to a length of 35 mm.

As mentioned previously, this math will create webs on the end of tree branches. Inside of these webs and they will consume the leaves of the tree. The stage less for about six weeks. The final stage before they emerge as adults is the pupa stage. They overwinter in the bark and leaf litter at the base of trees. The paper is only 10 mm long and is dark brown. The cocoon is made of silk and detritus. When the Delta merges, it is known to be quite hairy and is white in color. The males have black or brown spots on the fore wings. The females are almost entirely white with a sprinkling of brown on the abdomen.