CLASS HEXAPODA Butterfly Graphic
Order: Lepidoptera
Common Name--Butterflies and Moths

Lepidoptera is pronounced in English as "le-pi-DOP-ter-a". The name is derived from Greek words for scale, "lepido", and wing, "ptera", and refers to the scales covering the wings in all butterflies and moths.

Some butterflies are called "skippers" because of their rapid skipping from flower to flower. Some moths have been called "millers" because their wings appear to be covered with dust, as the clothes of a person who mills grain. Many common names are used for different groups and species of Lepidoptera, such as swallowtails, hairstreak butterflies, silk moths, and owlets. Some Lepidoptera names refer to forms of the caterpillars (for example, woolly bears, cutworms, hornworms, and inchworms).


More than 165,000 species of moths and butterflies have been named in the world, and more than 11,400 occur in North America. The butterflies include about 17,550 species in the world and 754 species in North America. Of the North American moths, more than half of the species are microlepidoptera, which include many of the small sized moths. About 5,000 species are larger moths, or macrolepidoptera. More than 2,900 of the larger moths are members of the family Noctuidae, which includes the cutworms and owlet moths.


Lepidoptera occur almost anywhere that plants grow, although not all eat plants. Some species live on mountains at high altitudes where temperatures are too cold to fly at night. At high altitudes, both butterflies and moths often are adapted to fly during the warmer daytime. Some species occur only in tropical rain forests, prairies, bogs, and other specialized habitats. Some caterpillars can live in water, feeding on aquatic plants. Several species have become adapted to living in houses of people.

Form and Function

Most Lepidoptera have a long and coiled proboscis for sucking liquid food. A few primitive moths have mandibles for chewing instead of a proboscis. Giant silk moths have a small proboscis that does not suck liquids, and the adult never feeds.

The antennae in butterflies are knobbed or enlarged at the ends, whereas in moths, they are thread-like or feathery. Butterflies are usually brightly colored, whereas most moths have black, brown and other dull colors. However, some moths that fly during the day time resemble butterflies in having bright colors.

The wings of moths span from less than one-tenth inch to more than 12 inches. The largest butterfly, the Queen Alexandra butterfly (Ornithoptera alexandrae)of New Guinea, has a wingspan of 11 inches. Most moths hold their wings tent-like over their bodies when at rest. Females of some moths, like the cankerworms and bagworms, do not have wings. The gypsy moth female has large wings, but its large abdomen prevents it from flying.

Scales are flat and hollow hairs that cover the wings and bodies of Lepidoptera. These scales are filled with substances, which are known as pigments, that make many different colors. In addition to the colors that are visible to humans, some Lepidoptera have an ultraviolet color that is visible to the insect but not to humans. Many scales of the same color can be grouped together to form patterns on the wings. Lepidoptera that fly during the day time use these color patterns for communication.

In some Lepidoptera, scales have a form that reflects and scatters the light like a rainbow or a soap bubble. In the morpho butterfly, the color pigment of the wing is brown, which can be seen when viewed at an angle. If the angle of view is changed, a bright blue color is reflected and seen. This reflection of light to form a color different from the pigment is called iridescence. Iridescent colors are present in many moths and butterflies, especially tropical species. Photographs of morpho butterflies and other tropical species can be found at Chuck's Butterfly Page.

The colors and patterns of wings also are important for defense against predators. Some moths have spots on their wings that appear to be eyes of an owl or other large animal. If a moth with eye-spots is threatened by a bird, it can flash its wings to scare away this predator. Some butterflies have color patterns that resemble heads at the tips of their wings. If the predator strikes at this false head, the butterfly is able to escape more easily.

Many Lepidoptera use color and pattern as a disguise, or camouflage, to blend in with the background. Some moths and butterflies resemble dead leaves. Many moths, which rest during the daytime, are disguised as twigs, tree bark, lichens, or bird droppings.

The bodies of some butterflies are full of distasteful chemicals that larvae obtain from plants. These butterflies advertise their bad taste by having wings with warning colors. The distasteful monarch butterfly has orange and black wings to warn predators. Red, yellow, and white also are used as warning colors. Some species do not have distasteful chemicals, but they obtain protection by being an imitation, or mimic, of a distasteful species. The viceroy butterfly does not have distasteful chemicals, but it is protected from predation by being a mimic of the monarch.

Caterpillars have chewing mouthparts and very short antennae. They do not have compound eyes, but they usually have six simple eyes on each side of their heads. Caterpillars usually have three pair of legs on the thorax, four pairs near the middle of their abdomens, and one pair at the end of their abdomens. The five pairs of stump-like legs on the abdomen are called prolegs because they are not segmented like the true legs on the thorax. The ends of the prolegs have tiny hooks to help in holding onto a surface.

Caterpillars are slow moving and are often exposed to predators. The colors of many caterpillars blend with their backgrounds, which makes the caterpillars difficult to see. Caterpillars often have eye-spots, even some that appear to blink when the caterpillar moves. Other caterpillars resemble twigs, pieces of bark, and leaves that have been partly eaten. Some geometer caterpillars cover their bodies with pieces of leaves or flowers on which they are eating.

Caterpillars known as bagworms and casebearers live inside a protective bag or case. The caterpillar makes this portable house from silk and pieces of the plant on which it is feeding. As the caterpillar grows, it continually adds more silk and plant parts to the open end of its case.

Some caterpillars are protected by "stinging" hairs and spines. These hairs and spines can break off or penetrate the skin to cause a stinging sensation. Common stinging caterpillars in North America include the saddleback caterpillar and related slug caterpillars, puss caterpillar, and caterpillars of the io moth and buck moth.

Life Cycle

Lepidoptera have complete metamorphosis with egg, larva, pupa, and adult. After hatching from the egg, the caterpillar may feed for a few weeks or even a couple of years. Caterpillars of butterflies usually molt their skin four times before becoming a pupa. Caterpillars of moths have from three to nine molts, but five molts is most common. Depending on the species, the larval stage may last from a few weeks to a few years.

Mature caterpillars of some moths spin silken cocoons in which to pupate. Caterpillars of many moths burrow into the ground to pupate without a cocoon. A butterfly caterpillar does not spin a cocoon or burrow into the ground, and its bare pupa is called a chrysalis. The pupal stage can last for a few weeks up to several months. Many species spend the winter as a pupa.

Most butterflies and moths have short adult lives. Some species do not feed; they only live long enough to mate and lay eggs. Other species can live for several weeks, and even pass the winter in the adult stage.

Form and Feeding Habits

Most adult Lepidoptera have a proboscis to suck nectar and water. Lepidoptera also need salt in their diet. One way they obtain salt is by sucking water from mud puddles. A few moths feed on secretions from the eyes and noses of animals. Some tropical moths have a proboscis that can pierce a fruit to feed on the juice, and some can pierce the skin of an animal to feed on blood. Many moths and butterflies feed on decaying organic matter, such as dead animals and animal droppings.

Most caterpillars feed on different kinds of plants. Many species prefer particular parts of plants--leaves, stems, roots, flowers, fruit, or seeds. Some species will feed on dead or decaying plants. Ferns, mosses, fungi, and algae are also hosts for some Lepidoptera.

Caterpillars of some yucca moths feed on seeds of the yucca plant. The females of these yucca moths have special mouthparts for gathering pollen and pollinating the flower. Without this pollination by the female moth, her offspring would not have seeds on which to feed.

A few caterpillars feed on animal products. The family Tineidae includes some species with caterpillars that can eat hair, feathers, and even horns of animals. Clothes moths are pests of wool clothing.

Several kinds of caterpillars are predaceous and feed on scale insects and other Homoptera. Caterpillars of some butterflies (family Lycaenidae) will feed on honeydew of Homoptera as well as food passed by the mouths of tending ants. Some of these caterpillars trick the ants into carrying them to their nest in the ground. Once in the ant nest, the caterpillar eats the ants' young.

Most caterpillars that are seen by people are those that feed on the outer parts of the plants. Leaf mining caterpillars feed inside leaves, leaving their feeding tracks, or mines, as visible evidence of their presence. Some Lepidoptera make galls on plants, and others live in galls made by other insects. Many caterpillars are hidden because they feed in rolled leaves or between leaves that are tied with silk. Some caterpillars bore in stems and tree trunks and are seen rarely.

Natural Enemies

Insects are the main predators of Lepidoptera eggs and young larvae. Birds are probably more important predators of older and larger larvae. Caterpillars compose more than 70% of the food of some birds. Many small mammals feed on caterpillars and pupae, and bats eat many moths. Eggs and larvae often are parasitized by Diptera (family Tachinidae) and Hymenoptera (families Braconidae, Ichneumonidae, and others).

Caterpillars are often killed by diseases. The most common diseases are caused by bacteria and viruses. In recent years, bacteria and viruses have been made into insecticides to kill pest species.

Olympic Feats and Other Strange Facts

Moths were the first to invent a kind of velcro, which is used to stick two surfaces together. Many moths have a patch of hooked spines on the front wing that locks with a similar patch on top of the third segment of the thorax. When at rest, the moth locks the front wing and thorax together with this natural velcro.

There are almost twice as many species of butterflies in the world as there are birds.

The monarch butterfly in North America migrates to two main locations every fall to pass the winter. Monarchs that live west of the Rocky Mountains migrate to the California coast. Monarchs living east of the Rocky Mountains migrate to mountains in Mexico. Some monarchs fly as far as 1,500 miles. In the spring the monarchs in Mexico return northward to find milkweed plants on which to lay eggs. Only the offspring from the over-wintering adults will eventually return to the northern United States and Canada. More information on the monarch and its migration can be found at Project Monarch Butterfly and Monarch Watch.

Butterflies in the family Nymphalidae use only four legs. The first pair of legs are very small and brush-like.

Species of Exyra (family Noctuidae) live in and eat carnivorous pitcher plants, which capture and digest other insects.

The largest moths in the world are the Atlas moths, which include species that have wings with the greatest surface area of any insect. The great owlet, Thysania agrippina, has the greatest wingspan among moths with narrow wings that extend more than 12 inches.

Hearing organs are present on the front wings, abdomen, and thorax in different moths. Some caterpillars can hear sound with the hairs on their bodies.

The only insect that is not found in the wild is the silkworm, Bombyx mori, which is kept in cultures by man for production of silk.

The first chemical sex attractant ever identified was found in the silkworm.

Louis Pasteur was a major researcher on diseases of the silkworm during the 19th century. He also invented vaccines for human diseases and pasteurization, a process used to kill harmful bacteria in milk and other products that is still used today.

A few primitive moths have chewing mouthparts instead of a sucking proboscis. Moths in the family Micropterygidae use their mandibles to feed on pollen of flowers and spores of ferns.

Some ghost moths (family Hepialidae) can whistle through their tongues (proboscis).

Males of the lesser emperor moth, Eudia pavonia, can detect the female's pheromone at a distance of more than six miles.

The caterpillar of the polyphemus moth, Antheraea polyphemus, can eat 86,000 times its weight at birth in little less than two months.

Some caterpillars can travel to new locations by "ballooning." A silk thread is released by the caterpillar and picked up by the wind, carrying the caterpillar with it.

The Mexican jumping bean is a seed that contains the caterpillar of a moth in the family Tortricidae. When the bean is disturbed, the caterpillar moves suddenly to cause the bean to jump.

If a bagworm (Psychidae) is hungry, it can eat its own house, a bag that includes dried bits of its host plant.

In 1954, J. L. Jorgensen fed female bagworms Acanthopsyche atra to European robins. He found 30-40 eggs were alive and hatched into larvae after passing through the digestive tract of the bird. This gives evidence to one manner in which these moths are dispersed from one area to another.

The Good and The Bad

Lepidoptera include many serious pests of crops and forests in North America because of the feeding habits of the caterpillars. Pests of forests include the gypsy moth, tussock moth, tent caterpillar, spruce budworm, and others. Fruits are attacked by the peach tree borer, Oriental fruit moth, codling moth, and grape berry moth. Pests of field crops include the European corn borer, corn earworm, pink bollworm, several species of armyworms and cutworms, and many others. Photographs of many pest species can be found in the Kansas Department of Agriculture Photo Gallery .

Many moths and butterflies pollinate flowers, although they are less important than bees in the pollination of crops. Some flowers are pollinated mainly by sphinx moths, which have long tongues for reaching the nectar. About 10 percent of the trees in dry forests of Costa Rica are pollinated by sphinx moths.

Lepidoptera are good indicators of environmental quality. Many species of Lepidoptera feed only on a single species of plant in a habitat. A collection of moths and butterflies can indicate which plants are present. A healthy habitat with five hundred species of plants can have more than 1,500 species of moths. Half of this number can be collected in a single night with light traps that attract moths. The absence of some species of Lepidoptera can indicate an unhealthy habitat even though the host plant may be present.

Many kinds of caterpillars make silk with special glands near their mouths. Silk that is used by people comes from the silkworm, Bombyx mori. The silkworm has been raised in captivity for more than 4,500 years. Originally silk worms were raised in China, but they are raised now in several Asian countries.

Lepidoptera have played an important role in human culture. The beauty of butterflies and moths have made them favorite subjects in paintings, glassware, and other art. Cocoons of giant silk moths have been used as musical instruments. American Indians in Arizona and California would gather cocoons, remove the pupae, and insert pebbles to make cocoon rattles. Butterfly gardens and houses have become popular attractions at parks throughout the world. Many people are now planting flowers to attract butterflies to their backyard gardens.

Selected Families of North American Lepidoptera

Micropterigidae (mandibulate moths)

Hepidalidae (ghost moths)

Prodoxidae (yucca moths)

Tineidae (clothes moths and others)

Gracillariidae (leaf blotch miners)

Oecophoridae (oecophorid moths)

Coleophoridae (casebearers)

Gelechiidae (gelechiid moths)

Yponomeutidae (ermine moths)

Cossidae (carpenter moths)

Tortricidae (tortricid moths)

Limacodidae (slug caterpillars)

Pterophoridae (plume moths)

Pyralidae (pyralid moths)

Crambidae (crambid moths)

Hesperiidae (skippers)

Papilionidae (swallowtail butterflies)

Pieridae (white and sulphur butterflies)

Lycaenidae (hairstreaks, blues, and other butterflies)

Nymphalidae (brush-footed butterflies)

Danaidae (milkweed butterflies)

Geometridae (geometer moths, measuring worms)

Lasiocampidae (tent caterpillars and others)

Bombycidae (silkworm)

Saturniidae (giant silkworm moths and royal moths)

Sphingidae (sphinx or hawk moths, hornworms)

Notodontidae (prominent moths)

Lymantriidae (tussock moths, gypsy moths)

Arctiidae (tiger moths, woolly bears)

Noctuidae (cutworms, owlet moths, and others)

For a complete list of Lepidoptera families, see The Association of Tropical Lepidoptera Family Classification. A long list of links to Web Images of North American Moth Species is available from Furman University. Buggy Software has a free, downloadable tutorial about Florida butterflies as well a numerous color photographs.

Selected References

Borror, D.J., C.A. Triplehorn, and N.F. Johnson. An Introduction to the Study of Insects. Chicago: Saunders Publishing, 1989.

Emmel, Thomas C. Butterflies. New York: Alfred Knoph, Publishers, 1975.

Sandved, Kjell B. and Jo Brewer. Butterflies. New York: Harry N. Abrams, Publishers, 1976.

Scoble, Malcolm J. The Lepidoptera. Oxford, England: Oxford University Press.


For an extensive list of Lepidoptera Web sites, go to the Links Component of the module.

Picture Credits

Dr. Ross E. Hutchins (Deceased)
Mississippi Entomological Museum

Skipper with proboscis extended

Clubbed antennae of skipper

Tent-like wings of resting looper moth

Scales in eye spot of io moth

A disguised leaf-like butterfly

Caterpillar standing on prolegs

Pandora sphinx with eyespots

Bagworms in cases of silk and plant parts

Saddleback caterpillar with stinging spines

Budworm egg magnified with scanning microscope

Cocoon cut open to show pupa and larval skin

Swallowtail butterflies at puddle

Yucca moth pollinating flower

Leaf mine caterpillar, egg laid at arrow

Chalcid wasp parasite of moth pupa

Roost of migrating monarchs

Dr. Ronn Altig
Mississippi State University
Department of Biological Sciences

Tulip-tree silkmoth

Polyphemus moth

Dr. Richard L. Brown
Mississippi State University
Department of Entomology and Plant Pathology

Woollybear caterpillar

Tussock caterpillar

Collection of moths from Venezuela

Dr. Gerald T. Baker

Budworm egg magnified with scanning electron microscope

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