Mourning Cloak (Nymphalis antiopa) is a medium-large butterfly, with a wingspan of 2.25 to 4 inches (an unusually wide range). It can be seen in our local area from January through June. Numbers peak in February. Host plants are primarily different types of Willows (Salix), but also American Elm (Ulmus americana), Cottonwood (Populus deltoides), and Aspen (Populus tremuloides).
Adults primarily feed on sap, ripe and fallen fruits and sugary exudate from aphids. They are rarely seen nectaring on flowers.
Very rarely do butterfly caterpillars have a different name from the adults, but the Mourning Cloak caterpillar is also called Spiny Elm Caterpillar.
Caterpillars live in a communal web, and feed together. Adults live for 10 or 11 months, making this one of the longest-lived butterflies in North America. However, they are inactive for roughly half that lifespan. Adults emerge in June or July. After feeding briefly, they estivate until fall (estivation is a state of reduced metabolic activity akin to hibernation, except that it occurs in summer rather than winter). In the fall, they re-emerge to feed and store energy for hibernation. The active lifespan runs from whenever they emerge from hibernation (which differs in different parts of its range) to May or June.
This butterfly is native to both North America and Europe. It is found in most of North America, from south of the tundra to central Mexico. However, it is only rarely seen in the Gulf states and peninsular Florida. It is widespread in large parts of Europe, and is also found in some parts of Asia.
