butterfly weed: see milkweed.

butterfly flower, fringeflower, or poor-man's-orchid, any of the showy plants of the genus Schizanthus of the family Solanaceae (nightshade family), native to Chile but grown elsewhere as garden or greenhouse annuals. The flowers resemble butterflies and are found in a variety of colors, usually mottled. Butterfly flowers are classified in the division Magnoliophyta, class Magnoliopsida, order Polemoniales, family Solanaceae.

butterfly fish, common name for certain members of the Chaetodontidae, a family of reef-dwelling tropical fishes that also includes the angelfishes and is closely allied to the spadefishes and the tangs. All have compressed bodies and small mouths and teeth. Butterfly fish are carnivorous, feeding on crabs, barnacles, and other invertebrates. The fast and aggressive common butterfly fish, 5 to 8 in. (12.5-20 cm) long, is marked by dark lines through the eyes and near the tail. The angelfishes have spines on their gill covers and long filaments on their dorsal fins. The queen angelfish, a good food fish that reaches 2 ft (60 cm) in length, is colored in blues and yellows; the smaller, more numerous common angelfish is similar. The French angelfish is black with yellow scale edgings; the black angelfish is solid black; and the bizarre rock beauty has a black body with yellow head, fins, and tail. The spadefishes are larger (up to 3 ft/90 cm) and faster than the angelfishes and are valued both as food and as game fishes. They are barred in black and white. The tangs have variable coloration. They include the violet-brown doctorfish or surgeonfish, the 8-in. (20-cm) blue tang, and the larger and more abundant ocean tang of deep waters. The butterfly fishes are classified in the phylum Chordata, subphylum Vertebrata, class Osteichthyes, order Perciformes, family Chaetodontidae.

butterfly, any of a large group of insects found throughout most of the world; with the moths, they comprise the order Lepidoptera. There are about 12 families of butterflies. Most adult moths and butterflies feed on nectar sucked from flowers. In the process they may transfer pollen from one flower to another, and many plants depend on moths or butterflies for pollination. Like moths, butterflies have coiled, sucking mouthparts and two pairs of wings that function as a single pair; the wings are covered with scales that come off as dust when the insect is handled.

Butterflies can be distinguished from moths in several ways: the antennae of butterflies are knobbed at the tips, while those of moths almost never have terminal knobs and are often feathery; the body of a butterfly is more slender and usually smoother than that of a moth; butterflies are active by day, while most moths are nocturnal; when at rest most butterflies hold the wings vertically, while most moths flatten them against the surface on which they are resting. The skippers are intermediate in characteristics, but they are usually called butterflies. Some butterflies migrate, usually traveling toward the equator in the fall and away from it in the spring. The North American monarch butterfly makes mass migrations of several thousand miles.

Coloration

The Lepidoptera, especially the butterflies, are known for the beautiful colors and patterns of their wings. Red, yellow, black, and white pigments are found in the scales; the blues and greens, and the metallic, iridescent hues found especially in tropical species, are caused chiefly by refraction. Some butterflies are protectively colored to match the environment. Many conspicuously colored species are distasteful to birds, which learn to avoid them, and others are protected by their resemblance to the distasteful species (see mimicry). Among the most beautiful butterflies are the swallowtails, found all over the world, the monarchs, and the peacock and tortoiseshell butterflies.

Metamorphosis

Metamorphosis is complete, that is, the insect goes through four stages: egg, larva, pupa, and adult. The eggs, which hatch in 2 to 30 days, are usually laid on a plant that the larva (called a caterpillar) uses for food. Most caterpillars eat leaves. After the last of several molts the larva is transformed into a pupa with a hard, often sculptured outer integument, within which it changes to the adult form. The butterfly pupa is called a chrysalis, or chrysalid. Most chrysalids (unlike the pupae of most moths) are not enclosed in a cocoon; however, they are usually suspended from some object by a silken thread and may have a partial covering. Except in those species that winter in the pupa stage, the adult usually emerges from the integument in two or three weeks. Members of some species winter in the egg stage, others as larvae or adults. The adults of most species, however, live only about a month.

Classification

Butterflies are classified in the phylum Arthropoda, class Insecta, order Lepidoptera. The true butterflies form the superfamily Papilionoidea, and the skippers form the superfamily Hesperoidae.

Any of several lepidopteran species of the family Pieridae that are found worldwide. Adults have a wingspan of 1.5–2.5 in. (38–63 mm); the wings are white, with black marginal markings. The pattern and colour of many species vary with sex and season. Many of the green, slender larvae, most of which are covered with a short down, or pile, are pests of garden crops. The pupae are attached to a twig by a posterior spine and a girdle of silk. Seealso cabbage white.

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Any of more than 500 species (genus Papilio, family Papilionidae) of butterflies found worldwide except in the Arctic. Some have tail-like extensions of the hind wing. Colour patterns vary with species, sex, season, and sometimes location (see tiger swallowtail). Most adults have yellow, orange, red, green, or blue markings on an iridescent black, blue, or green background. The brightly coloured larvae eat foliage. Some have markings resembling a snake's head, and many discharge a bad-smelling substance when disturbed. The giant swallowtail (P. cresphontes), with a wingspan of 4–5.5 in. (10–14 cm), is the largest butterfly in the U.S. and Canada.

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or sulfur butterfly

Any of several species of butterflies (family Pieridae) that are found worldwide. Adults have a wingspan of 1.5–2.5 in. (35–60 mm). The colour and pattern of many species vary seasonally and between sexes, but they are generally bright yellow or orange. Some have two colour patterns; for example, Colias eurytheme is usually orange with black wing margins, but some females are white with black margins. Pupae are attached to a twig by a posterior spine and a girdle of silk. The larvae feed on clover and may seriously damage crops.

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Species (Danaus plexippus, family Danaidae) of milkweed butterfly, occurring worldwide but mainly in the Americas. It is the only lepidopteran species to make a true migration (a two-way flight by the same individual). In North America, thousands of monarchs gather in autumn, migrate southward, sometimes more than 1,800 mi (2,900 km), and return north in spring. The distinctive coloration of the adult's wings (reddish brown, with black veins, a black border, and two rows of spots) warns predators of its bad taste. Several other species derive protection by mimicking its coloration.

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Any member of the butterfly subfamily Lycaeninae (family Lycaenidae). Coppers are common and widely distributed. Adults, sometimes known as gossamer-winged butterflies, are delicate, with a wingspan of 0.75–1.5 in. (18–38 mm). They are rapid fliers, usually with iridescent wings. Coppers typically range from orange-red to brown, usually with a copper tinge and dark markings. Copper larvae feed on clover, dock, or sorrel.

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North American plant (Asclepias tuberosa) of the milkweed family, a stout, rough-haired perennial with long horizontal roots. The leafy, erect, somewhat branching stem is about 1–3 ft (0.3–0.9 m) tall. In midsummer it bears numerous clusters of bright orange flowers. Unlike most milkweeds, it has a scanty milky juice. It is native to dry fields and is often planted in wild gardens or grown as a border plant.

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or butterfly bush

Any of more than 100 species of plants constituting the genus Buddleia, native to tropical and subtropical areas of the world. The genus was formerly included in the family Loganiaceae (order Gentianales) but is now placed in the family Buddlejaceae (order Scrophulariales), which includes about 10 genera and more than 150 species. Most species of Buddleia have hairy or scaly leaves and clusters of purple, white, yellow, or orange flowers. Several species are cultivated as garden ornamentals.

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Any of more than 14,000 lepidopteran species found worldwide. Unlike moths, butterflies are active during the day and are usually brightly coloured or strikingly patterned. Distinctive features are club-tipped antennae and a habit of holding the wings vertically over the back when at rest. With few exceptions the larvae and adults eat plants. Butterflies are classified into five or six families. The metalmarks of the family Lycaenidae are found chiefly in the New World tropics; some members of the family Nymphalidae are called snout butterflies. Other species (with their families) include the white and sulphur butterflies (Pieridae), the swallowtail butterfly (Papilionidae), the blue, copper, and hairstreak butterflies (Lycaenidae), and the admiral, monarch, and painted lady (Nymphalidae).

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Any member of the widely occurring lepidopteran family Lycaenidae. Adults, sometimes known as gossamer-winged butterflies, are small and delicate, with a wingspan of 0.75–1.5 in. (18–38 mm). Blues are rapid fliers, and most species have iridescent wings. Larvae are short, broad, and sluglike. Some species secrete honeydew, a sweet by-product of digestion that attracts ants, which stroke the larvae with their legs to stimulate honeydew secretion.

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Any of several species of butterflies (family Nymphalidae) that are colourful, fast-flying, and much prized by collectors. The migratory red admiral (Vanessa atalanta), widespread in Europe, Scandinavia, North America, and North Africa, feeds on stinging nettles. The Indian red admiral (V. indica) is found in the Canary Islands and India. The white admiral (Limenitis camilla, or Basilarchia arthemis), a Eurasian and North American species, feeds on honeysuckle.

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