These caterpillars spend their larval life fattening up on leaves of poplars, aspens, and willows in forested and riparian habitats. With the approaching cold they will soon pupate and overwinter. In their short but spectacular adult stage, the moths have a wingspan of 3.5 inches and do not feed. Their only focus is to mate. They can be found coast to coast in the northern United States, plus all of Canada (including the arctic) and into Alaska. In the western states, to the west coast, they can be found as far south as Baja California Norte and western Texas.
Photo by Noel Moon on 9/18/20 in Missoula, MT