I discover a new neighborhood in Farmers Branch. All the homes have substantial acreage and enormous front lawns. Modest brick ranch houses are juxtaposed with massive mansions — two have six-car garages. Three or four of the mansions also have front yard sculpture ranging from bronzes of a child reading a book to a soldier holding a flag to butterflies.
According to Wikipedia, butterflies are insects from the order Lepidoptera, which also includes moths. Adult butterflies have large, often brightly colored wings and conspicuous, fluttering flight. Butterfly fossils date to the Paleocene, about 56 million years ago.
Butterflies have the typical four-stage insect life cycle. Winged adults lay eggs on the food plant on which their larvae — known as caterpillars — will feed. The caterpillars grow — sometimes very rapidly — and when fully developed, pupate in a chrysalis. When the caterpillar is fully grown, it makes a button of silk which it uses to fasten its body to a leaf or a twig. Then the caterpillar's skin comes off for the final time. Under this old skin is a hard skin called a chrysalis. The photo to the left shows the common crow butterfly chrysalis illustrating the Greek origin of the term: χρυσός (chrysós) for gold.
When metamorphosis is complete, the pupal skin splits, the adult insect climbs out, and after its wings have expanded and dried, it flies off. Some butterflies, especially in the tropics, have several generations in a year, while others have a single generation, and a few in cold locations may take several years to pass through their entire life cycle.
Butterflies are often polymorphic, and many species make use of camouflage, mimicry and aposematism (advertising by an animal to potential predators that it is not worth attacking or eating e.g., toxicity, venom, foul taste or smell, sharp spines, or aggressive nature) to evade their predators. Some, like the monarch and the painted lady, migrate over long distances. Many butterflies are attacked by parasites or parasitoids, including wasps, protozoans, flies, and other invertebrates, or are preyed upon by other organisms. Some species are pests because in their larval stages they can damage domestic crops or trees; other species are agents of pollination of some plants. Larvae of a few butterflies (e.g., harvesters) eat harmful insects, and a few are predators of ants while others live as mutualists in association with ants. Culturally, butterflies are a popular motif in the visual and literary arts.
Age
The earliest Lepidoptera fossils are of a small moth, around 190 million years ago. The oldest butterflies are approximately 55 million years old. The oldest American butterfly is approximately 34 million years old.
Life cycle
Butterflies in their adult stage can live from a week to nearly a year depending on the species. Many species have long larval life stages while others can remain dormant in their pupal or egg stages and thereby survive winters. The Melissa Arctic overwinters twice as a caterpillar. Butterflies may have one or more broods per year. Courtship is often aerial and often involves pheromones. In the photo above, the male small skipper has pheromone-releasing "sex brands" (dark line) on the upperside of its forewings. After courtship, butterflies then land on the ground or on a perch to mate. Copulation takes place tail-to-tail and may last from minutes to hours.
Eggs
Butterfly eggs are protected by a hard-ridged outer layer of shell. It is lined with a thin coating of wax which prevents the egg from drying out before the larva has had time to fully develop. Each egg contains many tiny funnel-shaped openings at one end; the purpose of these holes is to allow sperm to enter and fertilize the egg. Butterfly eggs vary greatly in size and shape between species but are usually upright and finely sculptured. Some species lay eggs singly, others in batches. Many females produce between 100 and 200 eggs. The photo above shows the eggs of a black-veined white butterfly on an apple leaf.
Caterpillars
Butterfly larvae — or caterpillars — consume plant leaves and spend practically all their time searching for and eating food. Although most caterpillars are herbivorous, a few species are predators: one species eats scale insects, while another eats ant larvae.
Pupal transformation
The pupal transformation into a butterfly through metamorphosis has held great appeal to mankind. To transform from the miniature wings visible on the outside of the pupa into large structures usable for flight, the pupal wings undergo rapid mitosis or cell division and absorb a great deal of nutrients. If one wing is surgically removed early on, the other three will grow to a larger size. In the pupa, the wing forms a structure that becomes compressed from top to bottom and pleated from proximal to distal ends as it grows, so that it can rapidly be unfolded to its full adult size.
Behavior
Butterflies feed primarily on nectar from flowers. Some also derive nourishment from pollen, tree sap, rotting fruit, dung, decaying flesh and dissolved minerals in wet sand or dirt. Butterflies are important as pollinators for some species of plants. In general, they do not carry as much pollen load as bees, but they are capable of moving pollen over greater distances.
Several species of butterflies need more sodium than that provided by nectar and are attracted by sodium in salt; they sometimes land on people, attracted by the salt in human sweat. Some butterflies also visit dung and scavenge rotting fruit or carcasses to obtain minerals and nutrients. In many species, this mud-puddling behavior is restricted to the males, and studies have suggested that the nutrients collected may be provided as a nuptial gift, along with the spermatophore, during mating.
Butterflies can only fly when their temperature is above 81°; when it is cool, they can position themselves to expose the underside of the wings to the sunlight to heat themselves up. If their body temperature reaches 104°, they can orientate themselves with the folded wings edgewise to the sun. Basking is an activity which is more common in the cooler hours of the morning.
Endangered species
The Queen Alexandra's birdwing is the largest species of butterfly in the world, with females reaching wingspans slightly in excess 9.8 inches. It is restricted to the forests of the Oro Province in eastern Papua New Guinea. The black grass-dart butterfly from New South Wales is also endangered.
Defenses
Camouflage is found in many butterflies. Some like the oakleaf butterfly and autumn leaf are remarkable imitations of leaves. As caterpillars, many defend themselves by freezing and appearing like sticks or branches. Others have behaviors such as rearing up and waving their front ends which are marked with eyespots as if they were snakes. Some papilionid caterpillars such as the giant swallowtail resemble bird droppings to be passed over by predators. Some species form mutualistic associations with ants and gain their protection. Behavioral defenses include perching and angling the wings to reduce shadow and avoid being conspicuous.
In art and literature
Butterflies have appeared in art from 3,500 years ago in ancient Egypt. In the ancient Mesoamerican city of Teotihuacan, the brilliantly colored image of the butterfly was carved into many temples, buildings, jewelery and emblazoned on incense burners. The butterfly was sometimes depicted with the maw of a jaguar, and some species were considered to be the reincarnations of the souls of dead warriors. The close association of butterflies with fire and warfare persisted into the Aztec civilization; evidence of similar jaguar-butterfly images has been found among the Zapotec and Maya civilizations. In the photo above, the butterfly patterns are:
A-B. Clay flat stamp with butterfly motif from Teotihuacan.
C. Hieroglyphic from the town of Ocuilán, representing a caterpillar with the head of a butterfly.
D-F. Clay flat stamp with butterfly motif from Azcapotzalco.
G. Incomplete stamp with a butterfly motif containing complex wing patterns from Teotihuacan.
H-I. Clay flat stamp with butterfly motif from Azcapotzalco.
The Norwegian naturalist Kjell Sandved compiled a photographic Butterfly Alphabet containing all 26 letters and the numerals 0 to 9 from the wings of butterflies. He worked at the Smithsonian’s National Museum of Natural History in Washington, D.C., and came up with the idea with Barbara Bedette, a paleontologist, of finding all 26 letters of the Latin alphabet and the Arabic numerals 0 to 9 in the patterns on the wings of butterflies. His photographic excursions led him to Brazil, Congo, Papua New Guinea and the Philippines. Searching for the forms took him over 24 years, but he finished the collection in 1975 and published it in the Smithsonian Magazine. It was republished by Scholastic as a book in 1996, with accompanying snippets about butterfly species. The photo above shows a close-up of wing of the citrus swallowtail with the letter “C” drawn in scales.
Sir John Tenniel drew a famous illustration of Alice meeting a caterpillar for Lewis Carroll’s Alice in Wonderland, c. 1865. The caterpillar is seated on a toadstool and is smoking a hookah; the image can be read as showing either the forelegs of the larva, or as suggesting a face with protruding nose and chin. Eric Carle’s children's book The Very Hungry Caterpillar portrays the larva as an extraordinarily hungry animal, while also teaching children how to count to five and the days of the week.
Madam Butterfly is a 1904 opera by Giacomo Puccini about a romantic young Japanese bride who is deserted by her American officer husband soon after they are married. It was based on John Luther Long’s short story written in 1898.
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