From our perspective, the plant is irritating. Our initial reaction is to get rid of it. After all, what good is it? Before you dash for your gloves and loppers, understand that several native butterfly species are dependent on stinging nettle as their larval host plant, that is, the plant upon which their caterpillars feed. Without the host plant, the butterflies would not survive.
Milbert's tortoiseshell, Nymphalis milberti, a two-inch brown butterfly with an orange-yellow band highlighting the outer third of its wings, is totally dependent on stinging nettle as a host. Unlike most other butterfly species which lay single eggs on many plants, a female Milbert's tortoiseshell lays her eggs in large clusters on the underside of nettle leaves. After hatching, the young larvae feed on nettles within silky communal webs. As the young grow and molt, they wander to neighboring nettle plants to feed alone and rest in folded leaf shelters. When it's time to pupate and transform into adult butterflies, the fully-grown larvae crawl off the nettles, never to return.
Red admiral butterflies, Vanessa atalanta, can't survive Wisconsin winters and must, as migrants, recolonize the state each year from the south. Some years red admirals are plentiful, other years they are scarce. In their wanderings, red admirals search for stinging nettle and wood nettle. Females lay their eggs singly on nettles and the larvae feed on the tender leaves.
Larvae of several orange and dark brown anglewing butterflies feed on nettles as well as other plants. Question mark larvae, Polygonia interrogationis, feed on elm, hackberry and nettles. The eastern comma, P. comma, lays her eggs singly or in a short stack directly on nettles, elms or hops. The rare satyr comma, P. satyrus, of northern Wisconsin uses nettle as its only host plant. The pale-green eggs are laid on the lower surface of nettle leaves. Like other anglewings, the young caterpillars rest inside folded leaf shelters. It appears the larvae are unaffected by the stinging hairs, though scientists don't understand how they are protected from the nettle's chemical defenses.
Learn to recognize stinging nettle, walk around it and think twice before cutting it down. Some people even plant stinging nettle in butterfly gardens along with common milkweed, everlasting and violets. All the butterflies that feed on nettles are wanderers so you're more likely to have these colorful visitors find your garden than many other butterfly species. As an added bonus, study your growing nettle patch to discover other creatures that live and dine on this delicacy.
