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.

[24]: 246 Lepidopterans undergo a four-stage life cycle: egg; larva or caterpillar; pupa or chrysalis; and imago (plural: imagines) / adult and show many variations of the basic body structure, which give these animals advantages for diverse lifestyles and environments.

The antennae of butterflies are usually filiform and shaped like clubs, those of the skippers are hooked, while those of moths have flagellar segments variously enlarged or branched.

[31] Scales function in insulation, thermoregulation, producing pheromones (in males only),[32] and aiding gliding flight, but the most important is the large diversity of vivid or indistinct patterns they provide, which help the organism protect itself by camouflage or mimicry, and which act as signals to other animals including rivals and potential mates.

In the digestive system, the anterior region of the foregut has been modified to form a pharyngeal sucking pump as they need it for the food they eat, which are for the most part liquids.

[26]: 279  Some, like the luna moth, exhibit no digestive system whatsoever; they survive as adults from stored energy consumed as larvae and live for no longer than 7–10 days.

[15] Environmental polymorphism, in which traits are not inherited, is often termed as polyphenism, which in Lepidoptera is commonly seen in the form of seasonal morphs, especially in the butterfly families of Nymphalidae and Pieridae.

Unless the species reproduces year-round, a butterfly or moth may enter diapause, a state of dormancy that allows the insect to survive unfavorable environmental conditions.

[15] Some species engage in a form of acoustic courtship, or attract mates using sound or vibration such as the polka-dot wasp moth, Syntomeida epilais.

Celestial objects are so far away, even after traveling 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.

[70] The most well-known migrations are those of the eastern population of the monarch butterfly from Mexico to northern United States and southern Canada, a distance of about 4,000–4,800 km (2,500–3,000 mi).

In Costa Rica and Panama, the first population movements may begin in July and early August and depending on the year, may be very massive, continuing unabated for as long as five months.

They are integral participants in the food chain; having co-evolved with flowering plants and predators, lepidopteran species have formed a network of trophic relationships between autotrophs and heterotrophs, which are included in the stages of Lepidoptera larvae, pupae, and adults.

The flowers have simple nectar guides, with the nectaries usually hidden in narrow tubes or spurs, reached by the long "tongue" of the butterflies.

Most hawk moths are nocturnal or crepuscular, so moth-pollinated flowers (e.g., Silene latifolia ) tend to be white, night-opening, large, and showy with tubular corollae and a strong, sweet scent produced in the evening, night, or early morning.

[98] In reverse, moths and butterflies may be subject to parasitic wasps and flies, which may lay eggs on the caterpillars, which hatch and feed inside its body, resulting in death.

[26]: 750 In response to a parasitoid egg or larva in the caterpillar's body, the plasmatocytes, or simply the host's cells can form a multilayered capsule that eventually causes the endoparasite to asphyxiate.

For example, the Hawaiian caterpillar (Hyposmocoma molluscivora) uses silk traps, in a manner similar to that of spiders, to capture certain species of snails (typically Tornatellides).

[98] Larvae of some species of moths in the Tineidae, Gelechiidae, and Noctuidae, besides others, feed on detritus, or dead organic material, such as fallen leaves and fruit, fungi, and animal products, and turn it into humus.

The authors of the study proposed that lepidopterans evolved a proboscis as an adaptation to drink from droplets and thin films of water for maintaining their fluid balance in the hot and arid climate of the Triassic.

[109] The earliest named lepidopteran taxon is Archaeolepis mane, a primitive moth-like species from the Early Jurassic, dated back to around 190 million years ago, and known only from three wings found in the Charmouth Mudstone of Dorset, UK.

[113] The cladogram, based on molecular analysis, shows the order as a clade, sister to the Trichoptera, and more distantly related to the Diptera (true flies) and Mecoptera (scorpionflies).

[120] Today, butterflies are widely used in various objects of art and jewelry: mounted in frames, embedded in resin, displayed in bottles, laminated in paper, and in some mixed media artworks and furnishings.

[122] The skull-like marking on the thorax of the death's-head hawkmoth has helped these moths, particularly A. atropos, earn a negative reputation, such as associations with the supernatural and evil.

According to Kwaidan: Stories and Studies of Strange Things, by Lafcadio Hearn, a butterfly was seen in Japan as the personification of a person's soul; whether they be living, dying, or already dead.

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.

[123] In the ancient Mesoamerican city of Teotihuacan, the brilliantly colored image of the butterfly was carved into many temples, buildings, jewelry, and emblazoned on incense burners in particular.

Butterfly ranching in Papua New Guinea permits nationals of that country to "farm" economically valuable insect species for the collectors market in an ecologically sustainable manner.

The ingluvies, despite having a very low cyanogenic content, serve as a convenient, supplementary source of sugar to the children who can include this resource as a seasonal delicacy at minimum risk.

Caterpillar hairs sometimes have toxins in them and species from approximately 12 families of moths or butterflies worldwide can inflict serious human injuries (urticarial dermatitis and atopic asthma to osteochondritis, consumption coagulopathy, renal failure, and intracerebral hemorrhage).