March 11, 2013

Fluttering Wings of Spring

By Margaret Gillespie

Courtesy flickr SD Dirk
All of us have had some variation of this experience. You are handed of list of rather obscure landmarks designed to lead you to a specific location. With a bright but ominous smile, the giver of directions says, “You can’t miss it!” Later, as you attempt to find your destination but feel quite lost, around the corner you go and ahead is one of the elusive landmarks. Something inside you leaps with excitement . . . you know you are on the right track after all. This is the kind of thrill I feel as I wander out of winter toward spring, searching for landmarks that will tell me I’m approaching this season of new beginnings. Sighting some of the early spring butterflies can give me just the kind of lift I need.

Butterflies, as well as moths, belong to the insect order, Lepidoptera, coming from Greek words, lepid, meaning “scale” and ptera translating as “wing.” Giving these creatures such brilliant colors, scales are actually modified hairs, best seen under a microscope, but rubbing off like powder when touched. Butterflies are active by day and always have thin antennae with a swelling or club at the end. With some exceptions, moths are nocturnal but always have antennae that are hair-like, saw-toothed or feathery. Members of Lepidoptera overwinter as eggs, larvae, pupae or as adults, emerging at different times throughout the spring and summer.

The first butterfly prize of the spring is the Mourning Cloak (Nymphalis antiopa), named for its maroon wings edged with blue spots and a yellow border, resembling a cloak worn in times past when in mourning. With a wingspan of approximately three inches, this butterfly hibernates through the winter as an adult, coming out of its hiding place under the bark as early as March. To see one, choose a sunny day with temperatures nudging 60 degrees Fahrenheit and explore deciduous woodlands where Mourning Cloaks will be seeking and sipping tree sap from broken branches, particularly maples or birches with high sugar content.

Courtesy flickr davidhofmann08
Once you have located a Mourning Cloak butterfly, what are some special things to observe? This butterfly is a member of the family Nymphalidae or “brush-footed butterflies,” whose front pair of legs are so reduced and hairy that they look like tiny brushes. The function is sensory but the result is that you seem to be looking at a four-legged butterfly rather than the six legs expected on an insect. When at rest, these dark, early spring butterflies set themselves up as solar-collectors, in a behavior called “basking.” To fly, they must raise their body temperature and do so by orienting their open wings and bodies to the sun. If disturbed, Mourning Cloaks flutter up, land on tree bark and effectively disappear by closing their wings and letting the brown cryptic coloration of the underside of their wings hide them. Watch also for “puddling,” an amazing behavior where butterflies gather in damp spots or shallow puddles; places minerals and nutrients have become concentrated as the water evaporates. In Donald and Lillian Stokes’ guide, The Butterfly Book, they describe how puddling is done mostly by males to obtain sodium and nutrients essential for mating. Speaking of mating, male Mourning Cloaks perch on branches in early spring, defending territories by chasing other males away and waiting for females to fly by. After mating, females will lay groups of eggs on twigs, willow being a favorite. Hatching coincides with fresh spring leaves that provide larval food as clusters of black, spiny caterpillars with dorsal red spots start a new generation.

The ballet of fluttering butterflies continues throughout the summer as different butterflies take center stage. Compton Tortoiseshells, orange-brown butterflies with dark and light patches, closely follow Mourning Cloaks. A special highlight is the Spring Azure – males being sky blue above and females having dark edging on the forewing tips, all on a one-inch wingspan.

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