moth

Moths
Emperor Gum Moth, Opodiphthera eucalypti
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Lepidoptera
(unranked):	Heterocera

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 because none of them represents a pair of "monophyletic groups". The reality is that butterflies are a small group that arose from within the "moths"^{[citation needed]} 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.

There are thought to be 150,000 to 250,000 different species of moth, with thousands of species yet to be described.^[1] Most species of moth are nocturnal, but there are crepuscular and diurnal species.

Etymology

Mating pair of Laothoe populi, or Poplar Hawk-moths, showing two different color variants

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 (/ˈmɒθər/, not /ˈmʌðər/).

Economic significance of moths

An adult male Pine Processionary Moth (Thaumetopoea pityocampa). This species is a serious forest pest when in larval state. Notice the bristle springing from the underside of the hindwing (frenulum) and running forward to be held in a small catch of the forewing, whose function is to link the wings together.

Poplar hawk-moth caterpillar
Laothoe populi

Moths, and particularly their caterpillars, are a major agricultural pest in many parts of the world. Examples include corn borers and bollworms.^[2] 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.^[3] 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 −8 °C (17.6 °F).^[4]

Moths are sturdy and usually are more resistant to pesticides than are mosquitoes and flies.^{[citation needed]}

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. As of 2002^[update], the silk industry produces over 130 million kilograms of raw silk, worth about 250 million U.S. dollars, each year.^[5][6][7] 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.^[3]

Attraction to light

Time exposure at floodlight showing moth flight paths

Moths frequently appear to circle artificial lights, although the reason for this behavior remains unknown. 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.^[8]

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.^[9] 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.

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.^[8]

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.^[10] 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.^[11] The male moth is thereby powerfully attracted to the flame. Other sources with different spike patterns, eg. hurricane lamps, 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 and parasites of moths

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

Baculoviruses are parasite double-stranded DNA insect viruses that are used mostly as biological control agents. They are members of the Baculoviridae, a family that is restricted to insects. Most baculovirus isolates have been obtained from insects, in particular from Lepidoptera.

There is evidence that ultrasound in the range emitted by bats causes flying moths to make evasive maneuvers because bats eat moths. Ultrasonic frequencies trigger a reflex action in the noctuid moth that cause it to drop a few inches in its flight to evade attack.^[12] Tiger moths also emit clicks which jam bats' echolocation.^[13][14]

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^[15]
• Death's-head hawkmoth (Acherontia spp.), is associated with the supernatural and evil and has been featured in art and movies
• Peppered moth (Biston betularia), the subject of a well-known study in evolution
• Luna moth (Actias luna)
• Grease Moth (Aglossa cuprina), known to have fed on the rendered fat of humans ^[16]
• Emperor Gum moth (Opodiphthera eucalypti)
• Polyphemus moth (Antheraea polyphemus)
• Bogong moth (Agrotis infusa), known to have been a food source for Southeastern indigenous Australians
• Acropteris iphiata, found in Japan, China and Korea
• Smithmoth (Smithosmothos sporadica), found in South-East Queensland, Australia

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
• Wax moths (Galleria mellonella, Achroia grisella), pests of bee hives

See also

• Baculovirus
• Butterfly
• Clothing Moth
• Difference between a butterfly and a moth
• Lepidoptera
• List of moths
• Moth dermatitis
• Piloprepes anassa
• Pollination

Gallery

This section looks like an image gallery. Wikipedia policy discourages galleries of random images of the article subject; please edit or remove the section accordingly, moving freely licensed images to Wikimedia Commons if not already hosted there.

Forester Moth Zygaenidae	A moth	Case Moth Psychidae	Wood Boring Moth Cossidae
Giant Leopard Moth Arctiidae	Dryocampa rubicunda Rosy Maple Moth	Grammia parthenice Tiger Moth	Nyctemera amica Arctiidae
Chrysiridia rhipheus	Lyssa zampa Uraniidae Grey Sunset Moth	Oldwife Underwing Catocala neogama	Hemaris thysbe Hummingbird Clearwing Moth
Underside of a moth	Polyphemus Moth

References

External links

Wikimedia Commons has media related to: Lepidoptera

• 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
• Moths of French Guyana
• 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