I’ve come across this cool creature only a few times – most recently one was attracted to our deck light one evening. This insect is of a decent size, with about a two-inch wingspan.
While the adult is a Fall-flying, nocturnal leaf mimic, its caterpillar is cleverly disguised as a twig. The caterpillar does not limit its diet to maple; it’s also found on woody plants like birch, willow, tamarack, aspen, blueberry, cherry, and dogwood, and on herbaceous plants like soybeans, sweet-fern, and members of the geranium family.
Most often seen in September, Large Maple Spanworms Moths are a sign that the days of Summer are numbered. They’re found around woodlots and swamps across southern Canada and the northern half of the United States. Adults are nocturnal, and may rest on the sides of buildings during the day.
Belonging to a group known as Geometrid Moths, geometrid means “earth measurer,” and the caterpillars are fondly nicknamed “inchworms,” “loopers,” and “spanworms” because of their gait.
This moth has a quite cool shape and color to it. It almost looks like a brown leaf, and often the edges of its wings are a little ragged-edged and wavy as well. It’s always neat to come across one!