thumb|Peacock ([[Aglais io)]]

thumb|Crimson-spotted forester ([[Euphaedra themis)]]

thumb|Monarch butterflies ([[Danaus plexippus)]]

thumb|Dark blue tiger ([[Tirumala septentrionis)]]

thumb|Small pearl-bordered fritillary ([[Boloria selene)]]

thumb|thumbtime=8|[[Phyciodes|Crescent butterfly nectaring on yellow ironweed]]

The Nymphalidae are the largest family of butterflies, with more than 6,000 species distributed throughout most of the world. Belonging to the superfamily Papilionoidea, they are usually medium-sized to large butterflies. Most species have a reduced pair of forelegs and many hold their colourful wings flat when resting. They are also called brush-footed butterflies or four-footed butterflies, because they are known to stand on only four legs while the other two are curled up; in some species, these forelegs have a brush-like set of hairs, which gives this family its other common name. Many species are brightly coloured and include popular species such as the emperors, monarch butterfly, admirals, tortoiseshells, and fritillaries. However, the under wings are, in contrast, often dull and in some species look remarkably like dead leaves, or are much paler, producing a cryptic effect that helps the butterflies blend into their surroundings.

Nomenclature

Rafinesque introduced the name Nymphalia as a subfamily name in diurnal Lepidoptera. Rafinesque did not include Nymphalis among the listed genera, but Nymphalis was unequivocally implied in the formation of the name (Code Article 11.7.1.1). The attribution of the Nymphalidae to Rafinesque has now been widely adopted.

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Morphology

In the adult butterflies, the first pair of legs is small or reduced, giving the family the other names of four-footed or brush-footed butterflies. The caterpillars are hairy or spiky with projections on the head, and the chrysalids have shiny spots.

The trait for which these butterflies are most known is the use of only four legs; the reason their forelegs have become vestigial is not yet completely clear. Some suggest the forelegs are used to amplify the sense of smell, because some species possess a brush-like set of soft hair called setae, which has led researchers to believe the forelegs are used to improve signaling and communication between the species, while standing in the other four. This ability proves useful in terms of reproduction and the overall health of the species, and it is the leading theory so far.

The forewings have the submedial vein (vein 1) unbranched and in one subfamily forked near the base; the medial vein has three branches, veins 2, 3, and 4; veins 5 and 6 arise from the points of junction of the discocellulars; the subcostal vein and its continuation beyond the apex of cell, vein 7, has never more than four branches, veins 8–11; 8 and 9 always arise from vein 7, 10, and 11 sometimes from vein 7 but more often free, i.e., given off by the subcostal vein before apex of the cell.

The hindwings have internal (1a) and precostal veins. The cell in both wings is closed or open, often closed in the fore, open in the hindwing. The dorsal margin of the hindwing is channelled to receive the abdomen in many of the forms.

The five main clades within the family are:

The libytheine clade (basal)

  • Libytheinae (snout butterflies, earlier treated as the distinct family Libytheidae)

The danaine clade (basal)

  • Danainae (milkweed butterflies, earlier treated as the distinct family Danaidae)

: Host plant families include Apocynaceae, Asclepiadoideae (subfamily of Apocynaceae), and Moraceae.

:* Ithomiini (about 300 Neotropical species, sometimes considered a subfamily Ithomiinae)

:: Most species have long wings, and some have transparent wings. Host plants are in the families Apocynaceae, Gesneriaceae, and Solanaceae.

:* Tellervini (about 6–10 species in Australasia, sometimes considered a subfamily Tellervinae)

:: Caterpillars resemble those of the Danainae and feed on Apocynaceae.

The satyrine clade

  • Calinaginae (about six species, restricted to the Himalayas)

: Mimics of the Danainae, they are restricted to host plants in the family Moraceae.

  • Charaxinae

: Tropical canopy butterflies, the caterpillars often have head spines or projections. Mostly edible species, have some Batesian mimics. Host plants are in the families Annonaceae, Celastraceae, Convolvulaceae, Euphorbiaceae, Fabaceae, Flacourtiaceae, Lauraceae, Myrtaceae, Piperaceae, Poaceae, Rhamnaceae, Rutaceae, Santalaceae, and Sapindaceae.