Spring has sprung in full form and many of Connecticut’s ephemeral wildflowers have now finished their frenzy of flowering before being locked in shade by newly emerging, bright green leaves of trees. A few weeks ago I was fortunate to see one of the early spring butterflies in my yard: an adult Red Admiral (Vanessa atalanta).
I thought that the beginning of April was quite early for this butterfly to be flying around. Daytime temperatures were in the mid-50s (13 °C ) and in the 40s (7 °C) at night. Why was it out and about? Without much in bloom yet what flowers were providing nectar for it?
The Red Admiral adult I saw may have spent the winter in hibernation in a bark crevice or other tight cavity. Did it stay in the brush pile at the edge of my property? Unlike the Mourning Cloak (Nymphalis antiopa), Red Admirals usually can’t survive really cold winters.
In the fall, many Red Admirals migrate south, as far as southern Texas. In early April we had two strong and very stormy weather systems that transported warm, moist air from the Gulf of Mexico into our area. Remember those freakish record-breaking few days in the high 80s and 90s (25 °C to 35 °C)? It’s possible my Red Admiral arrived then.
This butterfly has evolved to survive early spring’s cool temperatures. The adult’s black background helps absorb heat. It also likes to feed on the sap running in trees, so doesn’t depend on nectar from flowers. They will occasionally feed on nectar later in the season. Red Admirals also gets minerals from bird droppings and dead animals.
Red Admirals have a worldwide distribution. They are found in the temperate regions of North Africa, North and Central America, Europe, Asia, Hawaii, and the Caribbean. Adults have a wingspan from 1.75 to 3 inches (4.5 to 7.6 cm). They are mostly black with broad orange (not red) bands on top of the fore- and hindwings. The upper forewings have white dots at the wingtips.
The Red Admiral was not named after a British naval commander, but rather by 18th-century naturalists. Its name is a corruption of the word “admirable.” This butterfly was first described by Carl Linnaeus in 1758.
The best way to attract Red Admirals to your yard is to plant one of its host plants, the plant where females choose to lay their eggs to provide food for the larvae, or caterpillars. The primary host plant for the Red Admiral is Stinging Nettle (Urtica dioica). Plant it in a shady spot with rich soil, but out of the way. Stinging Nettle has fine hairs on its leaves and stems that contain irritating chemicals. These are released when the plant comes in contact with skin. The hairs are normally very painful to the touch.
Stinging Nettle, however, does make a very healthy cooked green. Cook it like spinach, boiled in salted water for 45 seconds to a minute. According to an article published in the National Institutes of Health’s National Library of Medicine, its leaves have abundant fiber, minerals, vitamins, and antioxidant compounds like polyphenols and carotenoids.
If the idea of planting Stinging Nettle doesn’t suit you, try False Nettle (Boehmeria cylindrica), a related species that doesn’t have stinging hairs. It grows in the same rich, moist shady locations. False Nettle is hard to find, but can sometimes be discovered for sale online.
So, grow some larval food plants and the butterflies will come.