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Cool Insects
The Mourning Cloak Butterfly

This post is the first in a series featuring ‘cool’ and ‘cruel’ (pest) insects in Canada. If there’s an insect that you’d like to write a post about, please get in touch with us!


by John Acorn

The beautifully camouflaged under surface of a Mourning Cloak butterfly.

How long do butterflies live? For most, the answer is “not very long,” after what may have been many months as an egg, caterpillar, and chrysalis. For the Mourning Cloak (Nymphalis antiopa), however, life as a butterfly can stretch over an entire year. Mourning Cloaks spend the winter in hibernation, under bark for example, and they are often the “first butterfly of spring,” along with their close relatives, the tortoiseshells and commas. Since Mourning Cloaks are widespread in North America and Eurasia, they are probably the most oft-encountered spring butterflies in the north temperate world. After feeding on various trees (elm, willow, and poplar are all acceptable fare) as caterpillars, Mourning Cloak butterflies emerge from their pupae in mid to late summer. They sometimes live as long as twelve months as adults. In springtime, they typically emerge from hibernation before the first flowers are in bloom, and they feed on everything from sap flows to dung to mud, in order to obtain the nutrients necessary for such a long life.

On an older Mourning Cloak, the bright yellow wing edges have faded to pale white, and the maroon of the wings becomes a more generic shade of brown. The wing pattern of Mourning Cloaks has been the inspiration for speculation among entomologists. Most agree that the underside of the wings is camouflaged, looking like a dried leaf, or tree bark. But the upper side has been interpreted as a depiction of a yellow, black, and blue-spotted caterpillar, walking along a brown-maroon surface. Birds might peck at the fake caterpillar, thereby missing the delicate body of the butterfly, and indeed we do find Mourning Cloaks with bird bill marks along the edges of their wings (“cloak and dagger,” one might ask?). On the other hand, Mourning Cloaks are agile fliers, and at least one other insect, the Carolina Locust grasshopper (Dissosteira carolina), appears to mimic the Mourning Cloak, perhaps to convince birds that it is difficult to capture in flight.

A freshly emerged Mourning Cloak with bird bill marks along its wing margin. Wingspan approximately 7 cm.

In any event, the wings of Mourning Cloaks are similar to a traditional style of clothing worn when in mourning, but maroon or purplish mourning dresses with dull yellow trim were a matter of “half mourning” in Victorian England, whereas full mourning clothing was all black. In the UK, this species is known as the Camberwell Beauty, in remembrance of two migrant individuals (yes, this species will sometimes undergo “irruptive” migrations, in years when they are especially common) that made their way from the European mainland to Camberwell, a part of London. In French, the name is Morio, a word that also refers to starlings, birds that share a dark ground colour with yellow accents. As for the scientific name, Nymphalis means “nymph,” and refers to the forest nymphs of Greek mythology, while Antiope was the name of one of the mythical Amazons. You will find, however, that if you Google the word “antiopa,” almost all of the hits will refer to the butterfly, which has now eclipsed its namesake.

Links:

http://www.cbif.gc.ca/eng/species-bank/butterflies-of-canada/mourning-cloak/?id=1370403265696

http://entomology.museums.ualberta.ca/searching_species_details.php?fsn=nymphalis+antiopa&sb=1&r=2&o=1&c=2&s=2652&sn=Nymphalis+antiopa

Photos supplied by John Acorn