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A butterfly is an insect of the orrder Lepidoptera, and belongs to one of the superfamilies Hesperioidea (the skippers) or Papilionoidea (all other butterflies). Some authors have also suggested the inclusion of the superfamily Hedyloidea, the American butterfly moths. They are notable for their unusual life cycle with a larval caterpillar stage, an inert pupal stage and a spectacular metamorphosis into their familiar and colourful winged adult forms. The diverse patterns formed by their brightly coloured wings and their erratic-yet-graceful flight have made butterfly watching a popular hobby.
Etymology The Old English word for butterfly was buttorfleoge apparently because butterflies were thought to steal milk. A similar word occurs in Dutch and German originating from the same belief. This is believed to have led to the evolution of its present name form - butterfly. An alternative folk etymology, current in Great Britain, is that it originated as a contraction of term butter-coloured fly referring to the Brimstone Butterfly Gonepteryx rhamni, often the first butterfly of spring. Another such view is that the word butterfly came from a metathesis of "flutterby". Origin and distribution Butterflies are believed to have evolved from a branch of ancestral forms of moths. This branching is believed to have happened in the Cretaceous Period, the Age of Flowering Plants, 65 million to 135 million years ago. Butterflies are today distributed throughout the world except in the very cold or very arid regions. There are an estimated 18,000 living species of butterflies. Classification | |- | |- | |- | |} Presently butterflies are classified in two superfamilies, Hesperioidea, consisting of the 'skippers' and Papilionoidea or 'true butterflies'. These are sister taxa, so the butterflies collectively are thought to constitute a true clade. Some modern taxonomists place them all in superfamily Papilionoidea, distinguishing the skippers from the other butterflies at the series level only. In this system, Papilionoidea consists of the series Hesperiiformes (with one family only, the skipper family Hesperiidae) and the series Papilioniformes (with five families). Butterfly families The five families of true butterflies usually recognized in the Papilionoidea are:- Taxonomic issues A study combining morphological and molecular data concluded that Hesperiidae, Papilionidae, Pieridae, Lycaenidae and Riodinidae could all be strongly supported as monophyletic groups, but the status of Nymphalidae is equivocal. Lycaenidae and Riodinidae were confirmed as sister taxa, and Papilionidae as the outgroup to the rest of the true butterflies, but the location of Pieridae within the pattern of descent was unclear, with different lines of evidence suggesting different conclusions. The data suggested that the moths of Hedyloidea are indeed more closely related to the butterflies than to other moths. Some older classifications recognize additional families, for example Danaidae, Heliconiidae, Libytheidae and Satyridae, but modern classifications treat these as subfamilies within the Nymphalidae. Butterflies and moths The dichotomous classfication of lepidopterans into butterflies and moths is one that is popular but not used in taxonomy. The folk groups of butterflies and moths can be distinguished using several features however there are numerous exceptions to these rules. (See difference between a butterfly and a moth) The four stages in the lifecycle of a butterfly
Egg Butterfly eggs consist of a hard-ridged outer layer of shell, called the chorion. This 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 a number of tiny funnel-shaped openings at one end, called micropyles; the purpose of these holes is to allow sperm to enter and fertilize the egg. Butterfly and moth eggs vary greatly in size between species, but they are all either spherical or ovate. Butterfly eggs are fixed to a leaf with a special glue which hardens rapidly. As it hardens it contracts deforming the shape of the egg. This glue is easily seen surrounding the base of every egg forming a meniscus. The nature of the glue is unknown, and is a suitable subject for research. The same glue is produced by a pupa to secure the setae of the cremaster. This glue is so hard that the silk pad, to which the setae are glued, cannot be separated. Eggs are usually laid on plants. Each species of butterfly has their own hostplants. While some species are restricted to very specific host plants, others use a variety of species, often members of a common family. Caterpillars Larvae, or caterpillars, are multi-legged eating machines. They consume plant leaves and spend practically all of their time in search of food. Some larvae especially those of the Lycaenidae form mutualistic associations with ants. They communicate with the ants using vibrations that are transmitted through the substrate as well as using chemical signals. Although most caterpillars feed on the leaves of the hostplants, a few species are known to be carnivorous. Caterpillars mature through a series of stages, called instars. Near the end of each instar, the larva undergoes a process called apolysis, in which the cuticle, a mixture of chitin and specialized proteins, is released from the epidermis and the epidermis begins to form a new cuticle beneath. At the end of each instar, the larva moults the old cuticle, and the new cuticle rapidly hardens and pigments. Development of butterfly wing patterns begins by the last larval instar. Butterfly caterpillars have three pairs of true legs from the thoracic segments and upto 6 pairs of prolegs arising from the abdominal segments. These prolegs have rings of tiny hooks called crochets that help them grip the substrate. Some caterpillars have the ability to inflate parts of their head to appear snake-like. Many have false eye-spots to enhance this effect. Some caterpillars have special structures called osmeteria which are everted to produce smelly chemicals. These are all used as defense methods. The host plants of butterflies often have toxic substances in them. Caterpillars are often able to sequester these toxic substances and they are retained into the adult stage and helps in making them unpalatable to birds and other predators. Wing development
Pupa When the larva grows through all instars is fully grown, certain hormones such as prothoracicotropic hormone (PTTH) are produced. At this point the larva stops feeding and begins "wandering" in the quest of a suitable pupation site, often the underside of a leaf. The larva transforms into a pupa (chrysalis) by anchoring itself to a subtrate and moulting for the last time. The chrysalis is usually incapable of movement, although some species can rapidly move the abdominal segments or produce sounds to scare potential predators. 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 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. Several boundaries seen in the adult color pattern are marked by changes in the expression of particular transcription factors in the early pupa. Adult or Imago The adult, sexually mature, stage of the insect is known as the imago. As Lepidoptera, butterflies have four wings that are covered with tiny scales (see photo), but, unlike moths, the fore and hindwings are not hooked together, permitting a more graceful flight. A butterfly has six legs; the larva also has six true legs and a number of prolegs. After it emerges from its pupal stage, it cannot fly for some time, because its wings have not yet unfolded. A newly-emerged butterfly needs to spend some time 'inflating' its wings with blood and letting them dry, during which time it is extremely vulnerable to predators. External morphology
Polymorphism Many adult butterflies exhibit polymorphism, showing differences in appearance. These variations include geographic variants and seasonal forms. In addition many species have females in multiple forms, often with mimetic forms. Sexual dimorphism in colouration and appearance is widespread in butterflies. In addition many species have been shown to differ in the patterns of ultraviolet reflectivity, which are invisible to the unaided human eye. Genetic abnormalities such as gynandromorphs also occur from time to time. Batesian mimicry and Mullerian mimicry in butterflies is common. Wing markings called eyespots are present in some species; these may have an automimicry role for some species. In others, the function may be intraspecies communication, such as mate attraction. In several cases, however, the function of butterfly eyespots is not clear, and may be an evolutionary anomaly related to the relative elasticity of the genes that encode the spots.•• Habits
Flight Unlike many other members of the insect world, the flight of a butterfly can be explained quantitatively (and quite accurately) using steady-state, non-transitory aerodynamics. The aspect ratio of a butterfly's wing is ideal to be described using thin airfoil theory. The fluttering of the wings merely serves to enforce the Kutta condition of low-speed aerodynamics. For a more detailed description, see Insect flight. External Features of a Butterfly
Study of butterflies Scientists who study butterflies (or the closely related moths) are called lepidopterists and in former times were also known as aurelians. In earlier times, the study of butterflies invariably involved their capture and collection. The butterfly net and cabinet mark the Victorian era of natural history studies. The tools of butterfly research have changed over time. Molecular tools have become prominent in the study of butterflies. The basis for classification has gradually moved from morphological features to those based on DNA sequences. Field guides for various regions have made butterfly-watching and field studies popular. Collaborative studies have produced distribution maps, seasonal patterns and behavioural notes on a number of butterfly species. Most butterflies can be identified in the field based on their patterns, however some are notoriously difficult or impossible. In some groups, the species identity can be established only through dissection and examination of the genitalia. Some popular species There are between 15,000 and 20,000 species of butterflies worldwide. Some well known species from around the world include: China and Japan According to the “Butterflies” chapter in , by Lafcadio Hearn, a butterfly is seen as the personification of a person's soul, whether they be living, dying, or already dead. One Japanese superstition says that if a butterfly enters your guestroom and perches behind the bamboo screen, the person whom you most love is coming to see you. On the contrary, large numbers of butterflies are viewed as bad omens. When Taira no Masakado was secretly preparing for his famous revolt, there appeared in Kyoto so vast a swarm of butterflies that the people were frightened—-thinking the apparition to be a portent of coming evil. • Gallery Family Papilionidae- The Swallowtails Image:Iphiclides podalirius.jpg|Scarce Swallowtail, Iphiclides podalirius. Image:Black and blue butterfly KL.jpg|Palawan Birdwing, Troides trojana. Image:FlutterbySmall.jpg|Cairns Birdwing, Ornithoptera priamus. Image:Blue_mormon.jpg|Blue Mormon, Papilio polymnestor. Image:Orchard-Swallowtail-Butterfly.jpg|Orchard Swallowtail Butterfly, Papilio aegeus. Family Pieridae - The Whites and Yellows Image:Rapsweissling Pieris napi .jpg|Green-veined White, Pieris napi. Image:AnthocharisCardamines 2002Z.jpg|The Orange Tip, Anthocharis cardamines. Image:VV001 Delias eucharis Enhanced.JPG|Common Jezebel, Delias eucharis. Image:Gonepteryx rhamni1.jpg|Common Brimstone, Gonepteryx rhamni. Family Riodinidae - The Metalmarks, Punches and Judies Image:Abisara echerius1.jpg|The Plum Judy, Abisara echerius Image:RN007 Zemeros flegyas.jpg|Punchinello, Zemeros flegyas Image:RN008 Abisara neophron.jpg|Tailed Judy, Abisara neophron Image:Langesmetalmarkbutterfly91.jpg|Lange's Metalmark. Family Nymphalidae - The Brush-footed Butterflies Image:Xvisionxmonarch.jpg|Monarch Butterfly, The Monarch, Danaus plexippus the most widely known danaine butterfly. Image:Polyura_athamas.jpg|Common Nawab, Polyura athamas, a charaxine Nymphalid from India. Image:Butterfly Morpho Anaxibia (M) KL.jpg|Morpho rhetenor helena a morphine from South America. Image:Julia-heliconian-butterfly.jpg|Julia Heliconian, Dryas julia. Image:butterfly_panama.jpg|Sara Longwing, Heliconius sara a heliconine nymphalid. Image:Glasswing butterfly Panama.jpg|Glasswing butterfly, Greta oto. Image:Buberel butterfly.jpg|Lorquin's Admiral, Limenitis lorquini a limenitidine nymphalid. Image:Cethosia_cyane.jpg|Leopard Lacewing, Cethosia cyane of subfamily Cyrestinae. Image:Tagpfauenauge3.jpg|Peacock Butterfly, Inachis io. Image:Issoria lathonia.jpgQueen of Spain Fritillary, Issoria lathonia. Image:C-Falter Polygonia C-album.jpg|Comma Butterfly, Polygonia c-album. Image:Commonbuckeye.JPG|Common Buckeye, Junonia coenia. Image:Crimson_Patch_1.jpg|Crimson Patch, Chlosyne janais. Family Lycaenidae - The Blues Image:RN016 Talicada nyseus.jpg|Red Pierrot, Talicada nyseus. Image:Chrysophanus.phlaeas.2163.jpg|Small Copper, Lycaena phlaeas. Image:Rathinda amor.jpg|Monkey Puzzle, Rathinda amor. Image:Banded Blue Pierrot.JPG|Banded Blue Pierrot, Discolampa ethion. See also Field guides to butterflies General interest Regional lists Image repositories nah:Papalotl | |||||||||||||||||||||||||||||||||||||
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