Brush Footed Butterfly

The Nymphalidae are the world's largest butterfly family, with over 6,000 species found all over the globe. They are medium-sized to giant butterflies that belong to the Papilionoidea superfamily. Most species have shortened forelegs, and many rests with their colourful wings folded flat. Because they are known to stand on only four legs while the other two are curled up, they are also known as brush-footed butterflies or four-footed butterflies; in some species, the forelegs have a brush-like pair of bristles, which lends this family its other popular name. 

(Image will be uploaded soon)

Emperor butterflies, monarch butterflies, admirals, tortoiseshells, and fritillaries are just a few of the vividly coloured species. The under wings, on the other hand, are often drab and, in some species, resemble fallen leaves, or are much paler, giving the butterflies a cryptic appearance that helps them blend in with their surroundings. The Nymphalidae (brush-footed butterflies) and Riodinidae (metalmarks) butterfly families have reduced first thoracic limbs and only use two pairs of legs for locomotion. The three thoracic limbs of 13 species of butterflies spanning all six butterfly families were inspected and measured, and ancestral limb sizes for males and females were recreated individually to answer questions concerning the precise anatomy and evolutionary origins of these shortened limbs. 

Changes in limb segment size, rather than the number of limb segments, account for differences in limb size among butterflies. The femur appears to be notably affected by the reduction of the first limb in both nymphalids and riodinidae, however, the evolution of these decreased limbs is thought to be a convergent evolutionary event.

Nomenclature

Nymphalia was first used as a subfamily name in diurnal Lepidoptera by Rafinesque. Rafinesque did not include Nymphalis among the genera named, but it was unmistakably inferred in the name's derivation. Rafinesque's assignment of the Nymphalidae is now largely accepted.

Classification 

Adult butterflies have a short or reduced first pair of legs, earning the family the nickname four-footed or brush-footed butterflies. The chrysalids feature glittering markings and the caterpillars are hairy or spiky with projections on their heads.

The submedial vein (vein 1) in the forewings is unbranched and forked in one subfamily near the base; the medial vein has three branches, veins 2, 3, and 4; veins 5 and 6 are unbranched and forked in one subfamily near the base and The subcostal vein and its extension beyond the apex of the cell, vein 7, has never more than four branches, veins 8–11; 8 and 9 always come from vein 7, 10, and 11 occasionally from vein 7 but more commonly free, i.e., given off by the subcostal vein before the apex of the cell.

Internal and precostal veins run through the hindwings. Both wings have closed or open cells, with the forewing being closed and the hindwing being open. In many of the forms, the dorsal border of the hindwing is channelled to accommodate the abdomen.

A Specimen of Andromeda Satyr (Cithaerias Andromeda).

The club is varied in shape, and the antennae always have two grooves on the underside. The front pair of legs in the male, and with three exceptions (Libythea, Pseudergolis, and Calinaga) in the female, is decreased in size and functionally impotent throughout the family; in some, such as the Danainae and Satyrinae, the atrophy of the forelegs is significant. The forelegs are pressed against the underside of the thorax in several forms of these subfamilies and are often very inconspicuous in males.

Systematics and Phylogeny

The Nymphalidae have a complicated phylogeny. Several taxa are classified as ambiguous, indicating that some subfamilies were formerly regarded as different families due to insufficient research.

Within the family, there are five primary clades:

The Clade of Libytheine (basal).

• Libytheana is a genus of plants (snout butterflies, earlier treated as the distinct family Libytheidae).

The Danaine Clade

• The danaine clade is a subgroup of the danaine clade (basal).

• Danainae is a fictional character (milkweed butterflies, earlier treated as the distinct family Danaidae).

• Apocynaceae, Asclepiadoideae (a subfamily of Apocynaceae), and Moraceae are among the host plant families.

• Ithomiinae is a type of ithomiinae (about 300 Neotropical species, sometimes considered a subfamily Ithomiinae).

• The majority of species have lengthy wings, with some even having translucent wings. Plants in the Apocynaceae, Gesneriaceae, and Solanaceae families serve as hosts.

• Tellervini (a subfamily of the Tellervinae with roughly 6–10 species in Australasia)

• Caterpillars resemble Danainae caterpillars and feed on Apocynaceae.

The Satyrine Clade

• Calinaginae is a type of calinaginae (about six species, restricted to the Himalayas).

• They are restricted to host plants in the Moraceae family, as they are Danainae mimics.

• Charaxinae

The caterpillars of tropical canopy butterflies typically have head spines or extensions. There are some Batesian mimics among the most edible species. Annonaceae, Celastraceae, Convolvulaceae, Euphorbiaceae, Fabaceae, Flacourtiaceae, Lauraceae, Myrtaceae, Piperaceae, Poaceae, Rhamnaceae, Rutaceae, Santalaceae, and Sapindaceae are some of the host plant families.

• Morphinae are a kind of morphine (including Amathusiini, sometimes considered a subfamily Amathusiinae).

• Its food plants include the Arecaceae, Bignoniaceae, Fabaceae, Menispermaceae, Poaceae, and Sapindaceae, as well as the beautiful neotropical Morpho.

• Brassolini (a neotropical owl family with 70–80 species, most of which are crepuscular, and which is sometimes considered a subfamily of the Brassolinae).

• Plants in the Arecaceae, Bromeliaceae, Heliconiaceae, Musaceae, and Poaceae families serve as hosts.

• Satyrinae is a genus of Satyrinae (satyrs and browns, earlier treated as distinct family Satyridae).

• Arecaceae, Araceae, Cyperaceae, Heliconiaceae, Poaceae, and Selaginellaceae are some of the host plant families.

The Heliconiine Clade 

• The heliconiinae clade is a subgroup of the heliconiine clade (sister group of the nymphaline clade, excludes former tribes Biblidini and Cyrestini, and tribes Pseudergolini and Codeine).

• Heliconiinae (earlier treated as distinct family Heliconiinae)

• They are colourful tropical butterflies known for Müllerian mimicry. Plants in the Passifloraceae family serve as hosts for all species.

• Host plants are in the families Asteraceae, Passifloraceae, Sterculiaceae, Tiliaceae, and Urticaceae. Acraeini (mainly African, but some species in Asia, sometimes considered a family Acraeinae).

• Limenitidinae

The Clade of the Nymphaline

• The clade of the nymphaline is a sister group of the heliconiine clade that includes tribes Coeini and Pseudergolini.

• Apaturinae found in this clade is mostly tropical.

• Ulmaceae is the family of host plants. Caterpillars have bifid tails and horns on their heads and are smooth.

• Biblidinae was formerly included in Limenitidinae.

• Cyrestinae was formerly included in Limenitidinae.

• Some species of Nymphalidae (a broad subfamily that includes the Limenitidinae and Biblidinae) migrate. Caterpillars can have spines on their bodies. Acanthaceae, Caprifoliaceae, Convolvulaceae, Euphorbiaceae, Fagaceae, Flacourtiaceae, Lamiaceae, Loranthaceae, Moraceae, Plantaginaceae, Poaceae, Rubiaceae, Rutaceae, Salicaceae, Sapindaceae, Scrophulariaceae, Urticaceae, Verbenaceae, and Verben.

Morphology 

The use of only four legs is the most well-known characteristic of these butterflies; the reason for their vestigial forelegs is unknown. Some experts believe the forelegs are used to improve signalling and communication between species while standing in the other four. Some species have a brush-like set of soft hair called setae, which has led researchers to believe the forelegs are employed to amplify the sense of smell. This capacity is beneficial to reproduction and the species' overall health, and it is currently the main theory.

Some Examples of Nymphalidae are:

• Archdukes, genus Lexias

• California tortoiseshell, Nymphalis californica

• Comma, Polygonia c-album

• Common buckeye, Junonia coenia

• Common snout butterfly, Libytheana carinenta

• Cracker butterflies, genus Hamadryas

• Crimson patch, Chlosyne janais

• Edith's checkerspot, Euphydryas editha

• Grayling (butterfly), Hipparchia semele

• Hackberry emperor, Asterocampa celtis

• Lorquin's admiral, Limenitis lorquini

• Marsh fritillary, Euphydryas aurinia

• Meadow brown, Maniola jurtina

• Mourning cloak, Nymphalis antiopa

• Monarch butterfly, Danaus plexippus

• Blue morpho, Morpho menelaus

• Painted lady, Vanessa cardui

Lepidoptera

The Lepidoptera is one of the most successful insect groups. They can be found on all continents except Antarctica, and they live in a variety of terrestrial ecosystems ranging from desert to rainforest, lowland grasslands to mountain plateaus, but they are usually always linked with higher plants, particularly angiosperms (flowering plants). The Arctic Apollo (Parnassius arcticus), which lives in the Arctic Circle in northeastern Yakutia at an altitude of 1,500 metres (4,900 feet), is one of the most northern butterflies and moth species. Various Apollo species, such as Parnassius epaphus, have been documented up to an altitude of 6,000 metres (20,000 feet) above sea level in the Himalayas.

Some species of lepidoptera live in symbiotic, phoretic, or parasitic relationships with other organisms, rather than in the environment. Sloth moths, or coprophagous pyralid moths, such as Bradipodicola hahneli and Cryptoses choloepi, are remarkable in that they only live in the fur of sloths, which are mammals found in Central and South America. Two Tinea moth species have been found to feed on horny tissue and have been grown from bull horns. The Xenodochium coccinella larva is an internal parasite of the Kermes coccid species. Many species have been found to breed in natural or man-made items such as owl pellets, bat caves, honeycombs, or infected fruit.

There were around 174,250 lepidopteran species described as of 2007, with butterflies and skippers accounting for around 17,950 and moths accounting for the rest. The tropics are home to the great majority of Lepidoptera, however, most continents have significant diversity. In North America, there are about 700 species of butterflies and over 11,000 species of moths, whereas Australia has roughly 400 species of butterflies and 14,000 species of moths. John Heppner calculated the diversity of Lepidoptera in each faunal region in 1991, based on actual counts from the literature, card indices from the Natural History Museum (London) and the National Museum of Natural History (Washington), and estimates.

Distribution and Diversity of Lepidoptera

The Lepidoptera are one of the most successful insect groups. They can be found on all continents except Antarctica, and they live in a variety of terrestrial ecosystems ranging from desert to rainforest, lowland grasslands to mountain plateaus, but they are usually always linked with higher plants, particularly angiosperms (flowering plants). The Arctic Apollo (Parnassius arcticus), which lives in the Arctic Circle in northeastern Yakutia at an altitude of 1,500 metres (4,900 feet), is one of the most northern butterfly and moth species. Various Apollo species, such as Parnassius epaphus, have been documented up to an altitude of 6,000 metres (20,000 feet) above sea level in the Himalayas.

Some species of lepidoptera live in symbiotic, phoretic, or parasitic relationships with other organisms, rather than in the environment. Sloth moths, or coprophagous pyralid moths, such as Bradipodicola hahneli and Cryptoses choloepi, are remarkable in that they only live in the fur of sloths, which are mammals found in Central and South America. Two Tinea moth species have been found to feed on horny tissue and have been grown from bull horns. The Xenodochium coccinella larva is an internal parasite of the Kermes coccid species. Many species have been found to breed in natural or man-made items such as owl pellets, bat caves, honeycombs, or infected fruit.

There were around 174,250 lepidopteran species described as of 2007, with butterflies and skippers accounting for around 17,950 and moths accounting for the rest. The tropics are home to the great majority of Lepidoptera, however, most continents have significant diversity. In North America, there are about 700 species of butterflies and over 11,000 species of moths, whereas Australia has roughly 400 species of butterflies and 14,000 species of moths. John Heppner calculated the diversity of Lepidoptera in each faunal region in 1991, based on actual counts from the literature, card indices from the Natural History Museum (London) and the National Museum of Natural History (Washington), and estimates.

Polymorphism in Lepidoptera

Within a single species, polymorphism refers to the appearance of different forms or "morphs" that differ in colour and number of features. Polymorphism in Lepidoptera occurs not only between individuals in a population, but also between sexes as sexual dimorphism, between geographically dispersed populations as geographical polymorphism, and between generations flying at different times of the year as seasonal polymorphism (seasonal polymorphism or polyphenism). In some animals, polymorphism is only found in one sex, usually the female. When mimetic morphs fly alongside non-mimetic morphs in a population of a certain species, this is known as mimicry. Polymorphism occurs at two levels: at the individual level, with heritable variation in overall morphological adaptations, and at the species level, with heritable variation in specific morphological or physiological features.

Environmental polymorphism, in which qualities are not inherited, is known as polyphenism, and it is widely seen in Lepidoptera in the form of seasonal morphs, particularly in the Nymphalidae and Pieridae butterfly families. The common grass yellow (Eurema hecabe), an Old World pierid butterfly, exhibits a darker summer adult morph produced by a long day exceeding 13 hours in length, but the post-monsoon period induces a lighter morph triggered by a shorter diurnal period of 12 hours or less. The peppered moth, Biston betularia, is an example of polyphenism in caterpillars.

Geographic isolation leads a species' morphology to diverge into distinct forms. The Indian white admiral Limenitis procris, for example, has five distinct variants that are geographically separated by enormous mountain ranges. The Apollo butterfly is an even more spectacular example of regional polymorphism (Parnassius apollo). Because the Apollos live in small local populations, they have little contact with one another; this, combined with their strong stenotopic nature and limited migration ability, prevents interbreeding between populations of the same species; as a result, they form over 600 different morphs, with varying sizes of spots on their wings.

The occurrence of differences between males and females in a species is known as sexual dimorphism. It is prevalent in Lepidoptera and is virtually entirely determined by genetics. Sexual dimorphism can be found in all Papilionoidea families, but it is more prevalent in the Lycaenidae, Pieridae, and certain Nymphalidae species. 

Secondary sexual features may be present in addition to colour variation, which can range from subtle to wholly different colour-pattern combinations. At the same time, several genotypes maintained by natural selection may be expressed. In the case of some Papilionidae taxa, polymorphic and/or mimic females exist primarily to achieve a level of protection not available to the male of their species. Adult females of many Psychidae species only have vestigial wings, legs, and mouthparts, in contrast to adult males who are excellent fliers with well-developed wings and feathery antennae.

Did You Know?

• Some focus on thistles or nettles, while others focus on willow trees, daisy plants, and violets.

• Adults brush-footed butterflies drink nectar occasionally, but many species in this group prefer tree sap or rotting fruit, and some eat dung or muck.