Be on the Lookout for Red Admirals Butterflies in Spring
During spring migration, keep your eyes peeled for the common and stunning Red Admiral butterfly.
I’ve seen several news articles popping up from around the country lately about the large numbers of Red Admiral butterflies beginning to make their spring appearance. Red Admirals (Vanessa atalanta) are one of the most widespread butterfly species in the world, being found on six continents. One of the articles I read confidently declared that they appear on all seven continents, but I can assure you there are no butterflies on Antartica. They’re often one of the last butterflies seen in the fall before cold weather sets in, and the first ones seen in spring. Learn more about spring butterflies.
How to ID the Butterflies and Caterpillars
The Red Admiral is a medium-sized butterfly with a wingspan around 3 inches. The upper sides of the wings are dark brown to black, with vibrant bands of orange and white. The undersides of the wings are mottled brown and gray, perfectly designed for blending in with the trunks of trees when they land. Their caterpillars are brown and spiky, sometimes with muted orange bands. Although the caterpillars look as if they could be painful or toxic, they are in fact perfectly safe to handle.
Red Admirals owe some of their widespread success to wide variety of food sources they consume, both as caterpillars and adult butterflies. As caterpillars, they host on members of the nettle family, which can be found throughout the world. As adult butterflies, they nectar on flowers but also like tree sap and rotting fruit, allowing them to emerge in early spring before nectar flowers may be plentiful. When cold weather sets in, northernmost butterflies migrate south while those further south find sheltered nooks in trees or rocks to settle into for the winter as they enter diapause (hibernation). These adaptations enable them to survive in a variety of situations, from the United States to Europe to Asia and beyond.
Red Admirals are found nearly everywhere in the United States. Attract them to your yard with plenty of nectar plants, plus try leaving out a few pieces of overripe or rotting fruit—bananas or strawberries work well. They’ll be especially likely to stick around if you leave a few patches of their host plants in your yard as well. Though they host on unfriendly plants like stinging nettle (Urtica chamaedryoides) and tall wild nettle (U. gracilis), they’ll also use false nettle (Boehmeria cylindrica) and pellitory (Parietoria pennsylvanica), which are much safer in a garden or yard.