moth, any of the large and varied group of insects which, along with the butterflies, make up the order Lepidoptera. The moths comprise the great majority of the 100,000 species of the order, and about 70 of its 80 families. The adult moth, like the butterfly, has sucking mouthparts, two compound eyes, and two pairs of wings that function as a single pair and are covered with flattened, dustlike scales. It is distinguished from butterflies by its stouter, usually hairy body and its unknobbed, often feathery antennae. Most moths are nocturnal in their habits, while butterflies are mostly diurnal. A moth flattens its wings against the surface on which it is resting, while a butterfly holds them horizontally. Moths range in size from species with a wingspread of 1/6 in. (2 mm) to the Atlas moth with a wingspread of 10 in. (25 cm). Many are protectively colored to match their backgrounds: their patterns may exactly resemble, for example, certain lichens or the bark of certain trees. Many others have large, eyelike markings on the hind wings that are thought to frighten potential predators. Moths undergo a complete metamorphosis (see insect), from egg through larva and pupa to adult. Moth larvae, or caterpillars, are wingless and wormlike, with a row of simple eyes on either side of the body. They have chewing mouthparts and feed on leaves or other plant material. Many do great damage, such as the bee moth, the codling moth, the gypsy moth, the clothes moth, and the cutworm. The pupa of most moths is protected by a cocoon, built by the larva just before pupating. The cocoon is often made wholly or largely of silk; the cocoon of the domesticated silkworm moth is the source of commercial silk. Some moths make a cocoon of bits of wood or of a leaf, glued together with silk; some pupate underground. During pupation the body form changes to that of the winged adult. Most adult moths feed on the nectar of flowers, and many plants depend on them for pollination. The short-lived adults of certain species do not eat at all. Among the large and beautiful moths of North America are the cecropia moth, largest of the E United States, and the pale green luna moth. Moths are classified in the phylum Arthropoda, class Insecta, order Lepidoptera.

Typical member of the small European and New World lepidopteran family Liparidae (formerly Lymantriidae). The large, hairy larvae of most species have hair tufts, or tussocks; many have stinging hairs. Several species, including the gypsy moth, browntail moth, satin moth, and nun moth, damage trees. The larvae feed on foliage, sometimes foraging from a silken tent or a colonial nest of webbed leaves. Larvae pupate in a cocoon attached to a tree branch or trunk. Adult females range from white to brown; some, such as the white-marked tussock moth, are wingless. Seealso moth.

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Any of more than 3,500 species (family Arctiidae) of moths, many with furry or hairy larvae called woolly bears. Most adults have a thick body and white, orange, or green wings. At rest, the wings are folded rooflike over the body. The fall webworm (Hyphantria cunea) is a serious pest. The caterpillars construct webs over leaves, sometimes covering large areas with silken sheets. They pupate aboveground in a cocoon made of larval hairs and silk. The Isabella tiger moth (Isia isabella) attains a wingspan of 1.5–2 in. (37–50 mm). Black spots mark its abdomen and yellow wings.

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Any moth larva of the genus Malacosoma (family Lasiocampidae). Tent caterpillars are often brightly coloured. Congregations of the eastern tent caterpillar (M. americanum) of eastern North America spin huge, tent-shaped communal nests in forked tree branches. Eggs the moth deposits on a tree in midsummer hatch in spring. The hatched caterpillars migrate to a tree crotch and construct a silken tent, which they leave each day throughout the summer to feed on the surrounding leaves. The forest tent caterpillar (M. disstria) is common in the southern U.S.

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or sphinx moth

Any moth of the lepidopteran family Sphingidae. Found worldwide, these stout-bodied moths have long, narrow forewings and shorter hind wings, with wingspans ranging from 2 to 8 in. (5–20 cm). Many species pollinate flowers while sucking nectar; the proboscis of some species is up to 13 in. (32.5 cm) long. Some hawk moths migrate. The larvae, which are smooth and have a dorsal “horn,” are called hornworms; larvae of two North American species—the tobacco, or southern, hornworm, and the tomato, or northern, hornworm—attack tomato, tobacco, and potato crops.

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Any moth in the genus Bombyx (family Bombycidae). The Chinese silkworm (B. mori) has been used in commercial silk production for centuries. The adult, which has a wingspan of about 2 in. (50 mm) and a thick, hairy body, lives only two or three days. The female lays 300–500 eggs. The pale, naked larvae are fed mulberry leaves until pupation begins, when they are about 3 in. (75 mm) long. They spin a cocoon of one continuous white or yellow silken thread, about 1,000 yards (900 m) long. The pupa is killed with hot air or steam to preserve the thread intact. Seealso saturniid moth.

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or giant silkworm moth

Any of some 800 moth species of the principally tropical family Saturniidae. Adults have a stout, hairy body and broad wings, often vividly coloured and patterned. Most species have a central eyespot on each wing. Among the saturniids are the io moth (Automeris io); the giant cecropia moth (Hyalophora cecropia), the largest moth native to North America, with a wingspan of 6 in. (15 cm); several species of Antheraea that are used as a source of commercial silk; the emperor moth (Saturnia pavonia); and the luna moth.

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or owlet moth

Any of the more than 20,000 moth species in the lepidopteran family Noctuidae, common worldwide. Some species have a 1-ft (30-cm) wingspan, the largest of any moth, but most species have a wingspan of 1.5 in. (4 cm) or less. The wings are usually dull-coloured. Both larvae and adults of most species feed at night. Adults feed on fruits, sap, and nectar. The larvae of many species are agricultural pests (e.g., cutworm, bollworm) that feed on foliage and seeds, bore into stems and fruits, and eat or sever roots. A few species prey on scale insects.

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(born July 21, 1934, London, Eng.) British director, writer, and actor. After earning a medical degree at Cambridge University, he made his professional stage debut at the Edinburgh Festival in the hit satirical revue Beyond the Fringe (1960). As a director of plays, he gained notoriety for his controversial interpretations of classic works. His innovative opera productions, such as Pyotr Tchaikovsky's Eugene Onegin, for the English National Opera and other groups have become internationally celebrated. He wrote the BBC medical series The Body in Question (1977) and States of Mind (1982).

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(born Dec. 26, 1891, New York, N.Y., U.S.—died June 7, 1980, Pacific Palisades, Calif.) U.S. writer and perennial bohemian. Miller wrote about his Brooklyn, N.Y., childhood in Black Spring (1936). Tropic of Cancer (1934), a monologue about his life as an impoverished expatriate in Paris, and Tropic of Capricorn (1939), which draws on his earlier New York phase, were banned as obscene in the U.S. and Britain until the 1960s. The Air-Conditioned Nightmare (1945) is a critical account of a tour of the U.S. He settled on the California coast, where he became the centre of a colony of admirers and wrote his Rosy Crucifixion trilogy, Sexus, Plexus, and Nexus (U.S. ed., 1965).

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(born Oct. 17, 1915, New York, N.Y., U.S.—died Feb. 10, 2005, Roxbury, Conn.) U.S. playwright. He began writing plays while a student at the University of Michigan. His first important play, All My Sons (1947), was followed by his most famous work, Death of a Salesman (1949, Pulitzer Prize), the tragedy of a man destroyed by false values that are in large part the values of his society. Noted for combining social awareness with a searching concern for his characters' inner lives, Miller wrote many other plays, including The Crucible (1953), which uses a plot about the Salem witch trials to attack McCarthyism, A View from the Bridge (1955), After the Fall (1964), The Last Yankee (1992), and Resurrection Blues (2002). He also wrote short stories, essays, and the screenplay for The Misfits (1961), which starred his second wife, Marilyn Monroe.

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(born March 1, 1904, Clarinda, Iowa, U.S.—died Dec. 16, 1944, at sea) U.S. trombonist and leader of one of the most popular dance bands of the swing era. Miller formed his band in 1937. His music was characterized by the precise execution of arrangements that featured a clarinet doubling the saxophone melody. Broadcasts beginning in 1939 brought the band national exposure and millions of fans. Miller disbanded in 1942 to join the war effort by leading a military band. He was traveling from London to Paris by plane when the craft disappeared and was never recovered. His recordings of numbers such as “Moonlight Sonata,” “Chattanooga Choo-Choo,” “In the Mood,” and “String of Pearls” are classics of the era.

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(born July 21, 1934, London, Eng.) British director, writer, and actor. After earning a medical degree at Cambridge University, he made his professional stage debut at the Edinburgh Festival in the hit satirical revue Beyond the Fringe (1960). As a director of plays, he gained notoriety for his controversial interpretations of classic works. His innovative opera productions, such as Pyotr Tchaikovsky's Eugene Onegin, for the English National Opera and other groups have become internationally celebrated. He wrote the BBC medical series The Body in Question (1977) and States of Mind (1982).

Learn more about Miller, Jonathan (Wolfe) with a free trial on Britannica.com.

(born Dec. 26, 1891, New York, N.Y., U.S.—died June 7, 1980, Pacific Palisades, Calif.) U.S. writer and perennial bohemian. Miller wrote about his Brooklyn, N.Y., childhood in Black Spring (1936). Tropic of Cancer (1934), a monologue about his life as an impoverished expatriate in Paris, and Tropic of Capricorn (1939), which draws on his earlier New York phase, were banned as obscene in the U.S. and Britain until the 1960s. The Air-Conditioned Nightmare (1945) is a critical account of a tour of the U.S. He settled on the California coast, where he became the centre of a colony of admirers and wrote his Rosy Crucifixion trilogy, Sexus, Plexus, and Nexus (U.S. ed., 1965).

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(born July 21, 1899, Cicero [now in Oak Park], Ill., U.S.—died July 2, 1961, Ketchum, Idaho) U.S. writer. He began work as a journalist after high school. He was wounded while serving as an ambulance driver in World War I. One of a well-known group of expatriate writers in Paris, he soon embarked on a life of travel, skiing, fishing, and hunting that would be reflected in his work. His story collection In Our Time (1925) was followed by the novel The Sun Also Rises (1926). Later novels include A Farewell to Arms (1929) and To Have and Have Not (1937). His lifelong love for Spain (including a fascination with bullfighting) led to his working as a correspondent during the Spanish Civil War, which resulted in the novel For Whom the Bell Tolls (1940). Other short-story collections include Men Without Women (1927), Winner Take Nothing (1933), and The Fifth Column (1938). He lived primarily in Cuba from circa 1940, the locale of his novella The Old Man and the Sea (1952, Pulitzer Prize). He was awarded the Nobel Prize for Literature in 1954. He left Cuba shortly after its 1959 revolution; a year later, depressed and ill, he shot himself. The succinct and concentrated prose style of his early works strongly influenced many British and American writers for decades.

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(born July 21, 1899, Cicero [now in Oak Park], Ill., U.S.—died July 2, 1961, Ketchum, Idaho) U.S. writer. He began work as a journalist after high school. He was wounded while serving as an ambulance driver in World War I. One of a well-known group of expatriate writers in Paris, he soon embarked on a life of travel, skiing, fishing, and hunting that would be reflected in his work. His story collection In Our Time (1925) was followed by the novel The Sun Also Rises (1926). Later novels include A Farewell to Arms (1929) and To Have and Have Not (1937). His lifelong love for Spain (including a fascination with bullfighting) led to his working as a correspondent during the Spanish Civil War, which resulted in the novel For Whom the Bell Tolls (1940). Other short-story collections include Men Without Women (1927), Winner Take Nothing (1933), and The Fifth Column (1938). He lived primarily in Cuba from circa 1940, the locale of his novella The Old Man and the Sea (1952, Pulitzer Prize). He was awarded the Nobel Prize for Literature in 1954. He left Cuba shortly after its 1959 revolution; a year later, depressed and ill, he shot himself. The succinct and concentrated prose style of his early works strongly influenced many British and American writers for decades.

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(born May 17, 1873, Abingdon, Berkshire, Eng.—died June 17, 1957, Beckenham, Kent) English novelist. From age 17 she engaged in teaching, clerical work, and journalism. For much of her life she worked on her sequence novel Pilgrimage, comprising 13 volumes beginning with Pointed Roofs (1915). The final volume, March Moonlight, was published a decade after her death. A sensitive autobiographical account of a woman's developing consciousness, it was a pioneering work in stream-of-consciousness fiction.

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(born Oct. 17, 1915, New York, N.Y., U.S.—died Feb. 10, 2005, Roxbury, Conn.) U.S. playwright. He began writing plays while a student at the University of Michigan. His first important play, All My Sons (1947), was followed by his most famous work, Death of a Salesman (1949, Pulitzer Prize), the tragedy of a man destroyed by false values that are in large part the values of his society. Noted for combining social awareness with a searching concern for his characters' inner lives, Miller wrote many other plays, including The Crucible (1953), which uses a plot about the Salem witch trials to attack McCarthyism, A View from the Bridge (1955), After the Fall (1964), The Last Yankee (1992), and Resurrection Blues (2002). He also wrote short stories, essays, and the screenplay for The Misfits (1961), which starred his second wife, Marilyn Monroe.

Learn more about Miller, Arthur with a free trial on Britannica.com.

Any of more than 150,000 lepidopteran species, found in all but polar habitats. Moths are chiefly nocturnal and have a stouter body, duller colouring, and proportionately smaller wings than butterflies. They have distinctive feathery antennae and, when at rest, fold their wings, wrap them around the body, or hold them extended at their sides. Wingspans range from about 4 mm (0.16 in.) to nearly 30 cm (about 1 ft). The life cycle has four stages: egg, larva (caterpillar, or worm), pupa (chrysalis), and adult (imago). Both larvae and adults of most species are plant eaters, and many seriously damage forests, agricultural crops, and fabrics. Seealso bagworm moth; gypsy moth; hawk moth; luna moth; miller; saturniid moth; silkworm moth; tiger moth; tussock moth.

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Species (Lymantria dispar) of tussock moth, a serious pest of trees. The European strain was introduced into eastern North America circa 1869. The heavy-bodied, weak-flying female is white with black zigzag markings and a wingspan of 1.5–2 in. (38–50 mm). The smaller, darker male is a stronger flier. The voracious larvae can completely defoliate deciduous trees within weeks. The larger Asian gypsy moth (wingspan of about 3.5 in., or 90 mm) is even more threatening because the female is a stronger flier, enabling it to spread quickly, and the larvae eat the leaves of both conifers and deciduous trees. It was introduced into northwestern North America in 1991. Sprayed insecticides remain the most effective means of control.

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Any insect of the moth family Psychidae, found worldwide, named for the baglike cases the larvae (see larva) carry with them. The bag, which ranges in size from 0.25 to 6 in. (6–150 mm), is constructed from silk and bits of leaves, twigs, and other debris. The strong-bodied male has broad, fringed wings with a wingspread averaging 1 in. (25 mm). The wormlike female lacks wings. Bagworm larvae often damage trees, especially evergreens.

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A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. The differences between butterflies and moths are more than just taxonomy. Sometimes the names "Rhopalocera" (butterflies) and "Heterocera" (moths) are used to formalize the popular distinction. Many attempts have been made to subdivide the Lepidoptera into groups such as the Microlepidoptera and Macrolepidoptera, Frenatae and Jugatae, or Monotrysia and Ditrysia. Failure of these names to persist in modern classifications is due to the fact none of them represents a pair of "monophyletic groups". The reality is that butterflies are a small group that arose from within the "moths" and there is thus no way to group all of the remaining taxa in a monophyletic group, as it will always exclude that one descendant lineage.

Most species of moth are nocturnal, but there are crepuscular and diurnal species. They can be distinguished from butterflies in several ways.

Etymology

The Modern English word "moth" comes from Old English "moððe" (cf. Northumbrian "mohðe") from Common Germanic (compare Old Norse "motti", Dutch "Mot" and German "Motte" all meaning "moth"). Perhaps its origins are related to Old English "maða" meaning "maggot" or from the root of "midge" which until the 16th century was used mostly to indicate the larva, usually in reference to devouring clothes.

The study of butterflies and moths is known as lepidoptery, and biologists that specialize in either are called lepidopterists. As a pastime, watching butterflies and moths is known as butterflying and mothing. The latter has given rise to the term "mother" for someone who engages in this activity — sometimes written with a hyphen (moth-er) to distinguish it from its usual meaning. This confusion does not arise in speech as it is pronounced differently (not /ˈmʌðɚ/).

Economic significance of moths

Moths, and particularly their caterpillars, are a major agricultural pest in many parts of the world. The caterpillar of the gypsy moth (Lymantria dispar) causes severe damage to forests in the northeast United States, where it is an invasive species. In temperate climates, the codling moth causes extensive damage, especially to fruit farms. In tropical and subtropical climates, the diamondback moth (Plutella xylostella) is perhaps the most serious pest of brassicaceous crops.

Several moths in the family Tineidae are commonly regarded as pests because their larvae eat fabric such as clothes and blankets made from natural proteinaceous fibers such as wool or silk. They are less likely to eat mixed materials containing artificial fibers. There are some reports that they can be repelled by the scent of wood from juniper and cedar, by lavender, or by other natural oils. However, many consider this unlikely to prevent infestation. Naphthalene (the chemical used in mothballs) is considered more effective, but there are concerns over its effects on human health. Moth larvae may be killed by freezing the items which they infest for several days at a temperature below .

Moths are sturdy and usually are more resistant to pesticides than are mosquitoes and flies.

Some moths are farmed. The most notable of these is the silkworm, the larva of the domesticated moth Bombyx mori. It is farmed for the silk with which it builds its cocoon. , the silk industry produces over 130 million kilograms of raw silk, worth about 250 million U.S. dollars, each year. Not all silk is produced by Bombyx mori. There are several species of Saturniidae that are also farmed for their silk, such as the Ailanthus moth (Samia cynthia group of species), the Chinese Oak Silkmoth (Antheraea pernyi), the Assam Silkmoth (Antheraea assamensis), and the Japanese Silk Moth (Antheraea yamamai).

The mopane worm, the caterpillar of Gonimbrasia belina, from the family Saturniidae, is a significant food resource in southern Africa.

Despite being framed for eating clothing, most moth adults do not eat at all. Most like the Luna, Polyphemus, Atlas, Prometheus, Cercropia, and other large moths do not have mouths. When they do eat, moths will drink nectar. Only one species of moth eats wool. The adults do not eat but the larvae will eat through wool clothing.

Attraction to light

Moths frequently appear to circle artificial lights. One hypothesis advanced to explain this behavior is that moths use a technique of celestial navigation called transverse orientation. By maintaining a constant angular relationship to a bright celestial light, such as the Moon, they can fly in a straight line. Celestial objects are so far away, that even after travelling great distances, the change in angle between the moth and the light source is negligible; further, the moon will always be in the upper part of the visual field or on the horizon. When a moth encounters a much closer artificial light and uses it for navigation, the angle changes noticeably after only a short distance, in addition to being often below the horizon. The moth instinctively attempts to correct by turning toward the light, causing airborne moths to come plummeting downwards, and - at close range - which results in a spiral flight path that gets closer and closer to the light source.

In 1972, Henry Hsiao, now a professor of biomedical engineering, suggested that the reason for moths circling lights may have to do with a visual distortion called a Mach band. He says that they fly towards the darkest part of the sky in pursuit of safety and are thus inclined to circle ambient objects in the Mach band region. This hypothesis is not scientifically accepted and has never been confirmed.

Hsaio says that the celestial navigation theory should cause moths to circle lights, not to head directly toward them, as many are seen to do. He conjectures that moths, which are nocturnal creatures, must find a place to hide from predators when daylight comes, but cannot do so in darkness. Their instinct when morning comes is to fly toward the light (presumably up) and then down again, with some probability landing on a surface which matches their camouflage.

A theory which has been advanced in an attempt to explain the attraction male moths have for candles specifically is based on olfaction. There is evidence that olfaction might be, in some cases, mediated by detection of the infra-red spectra of substances. The spiky infrared spectra of a candle flame happens to contain a number of emission lines which coincide with the vibrational frequencies of the female moth's pheromone. The male moth is thereby powerfully attracted to the flame. Sources, eg. hurricane lamps, with different spike patterns are less powerful attractants.

Night-blooming flowers usually depend on moths (or bats) for pollination, and artificial lighting can draw moths away from the flowers, affecting the plant's ability to reproduce. A way to prevent this is to put a cloth or netting around the lamp. Another way is using a colored light bulb (preferably red). This will take the moth's attention away from the light while still providing light to see by.

Predators of moths

Nocturnal insectivores often feed on moths; these include some bats, some species of owls, but also other species of birds. Moths are also eaten by some species of lizards, some cats, some dogs, some rodents, and some bears. Moth larvae are vulnerable to being parasitized by ichneumonidae.

Notable moths

• Atlas moth (Attacus atlas), the largest moth in the world
• White Witch moth (Thysania agrippina), the Lepidopteran with the biggest wingspan
• Madagascan Sunset moth (Chrysiridia rhipheus), considered to be one of the most impressive and beautiful Lepidoptera
• Death's-head hawkmoth (Acherontia spp.), is associations with the supernatural and evil and was featured in art and movies
• Peppered moth (Biston betularia), the subject of a now well-known study in evolution
• Luna moth (Actias luna)
• Emperor Gum moth (Opodiphthera eucalypti)
• Polyphemus moth (Antheraea polyphemus)
• Bogong moth (Agrotis infusa), south eastern Indigenous Australians were known to have feasted on the moths.

Moths of economic significance:

• Gypsy moth (Lymantria dispar), a pest of hardwood trees in North America
• Corn earworm or cotton bollworm (Helicoverpa zea), a major agricultural pest
• Codling moth (Cydia pomonella), a pest mostly of apple, pear and walnut trees
• Light brown apple moth (Epiphyas postvittana), a highly polyphagous pest
• Silkworm (Bombyx mori), for its silk

See also

• Pollination
• Difference between a butterfly and a moth
• List of moths
• Lepidoptera
• Butterfly
• Clothing Moth

Gallery

References

External links

• European Butterflies and Moths by Christopher Jonko
• Moths of North America Diagnostic large format photographs, taxonomy, descriptions
• North American Moth Photographers Group Diagnostic photographs for thousands of species
• Bugguide - Moths
• Back Garden Moths
• Life cycle photos of the salt marsh moth Estigmene acrea
• UK Lepidoptera
• Butterflies and Moths of the Netherlands
• Helicoverpa Diapause Induction and Moth Emergence Tool
• Pterophoridae of North America
• moths on the UF / IFAS Featured Creatures Web site