Have you seen this moth? It is the Giant Leopard Moth, Hypercompe scribonia (Stoll, 1790) and is one of our largest moths with a wingspread ranging from 2¼ inches to slightly over 3½ inches. It belongs to the moth subfamily Arctiinae or Tiger Moths which contains some of the prettiest adult moths. The spots on the wings are black or bluish-black and may be either solid or hollow. When the wings are spread the abdomen is an iridescent bluish-black with orange markings laterally.
Photo by John Canning
Fully grown caterpillars, known as woolly bears, are almost 3 inches in length and covered with shiny black bristly setae. Body segments are separated by a bright red integument which is most easily seen when the caterpillar feels threatened and has curled up into a protective ball.
Photo by Micha L. Rieser Photo by Asturnut
The giant leopard moth is a native found from southern Ontario, Canada south to Florda and west to Texas and Minnesota. There is one generation in the North and probably two or three in our area. The caterpillars are polyphagous, feeding on a wide variety of woody plants and other low-growing broad-leaved plants that are not grasses. Some host plants include : cabbage, castorbean, cherry, dandelion, magnolia, plantain, poinsettia, poke-weed, sunflower, violet, and willow.
Like most moths, adults are active at night with males more readily attracted to lights. Often, in the fall, caterpillars can be found crawling over the ground searching for a place to pupate and spend the winter.
Although the caterpillars look fearsome with their bristly appearance, they are quite harmless. They don’t bite and the setae do not sting. The setae, however, may penetrate the skin if handled carelessly.
Kenneth R. Ahlstrom, Ph. D.
Entomologist, Economy Exterminators