A butterfly is an insect of the order Lepidoptera. characteristic of all
Lepidoptera, butterflies are remarkable for their extraordinary life cycle with
a larval caterpillar stage, an inactive pupal stage, and an amazing
metamorphosis into a familiar and colourful winged adult form. Most species fly
in the daytime where they always attract attention. The diverse patterns formed
by their brightly coloured wings and their erratic yet graceful flight have made
butterfly watching a popular pastime. //
Butterflies comprise of the true butterflies (superfamily
Papilionoidea), the skippers (Superfamily Hesperioidea) and the
moth-butterflies (Superfamily Hedyloidea). Butterflies exhibit polymorphism,
mimicry and aposematism. Some are known to migrate over large distances. Some
butterflies have evolved symbiotic and parasitic relationships with social
insects such as ants. Economically, butterflies are important by virtue of their
being one of the major agents of pollination, in addition to a number of species
which are pests on domestic crops and trees.
Culturally, butterflies are a popular motif in the visual and literary arts.
Origin and distribution
Butterflies are nested within the evolutionary tree of moths. Their origins
may date back to the Cretaceous Period, ending 65 million years ago.
Unfortunately, the fossil record is very limited. The oldest known fossil is an
unnamed possible skipper butterfly from the Upper Palaeocene (around 57 million
year old) of Fur, Denmark . One of
the most beautifully preserved is a Metalmark butterfly (Voltinia dramba)
from 25 million year old Dominican amber.
Butterflies are today distributed throughout the world except in the very
cold and arid regions. There are an estimated 17,500 species of butterflies (Papilionoidea)
out of about 180,000 species of Lepidoptera.
Presently butterflies are classified in three superfamilies, Hedyloidea,
consisting of the 'American moth-butterflies', Hesperioidea, consisting of the
'skippers' and Papilionoidea or 'true butterflies'. The last two superfamilies
are probably sister taxa, so the butterflies collectively are thought to
constitute a natural group or clade.
The scope of the term butterfly depends on how far the concept is
extended. Currently, most experts include the superfamilies Hedyloidea (the
American moth-butterflies), Hesperioidea (the skippers) and Papilionoidea (the
so-called 'true' butterflies). This concept of butterflies including the
Hedyloidea is a recently expanded one, but it makes the group a natural clade,
The five families of true butterflies usually recognized in the Papilionoidea
- Family Papilionidae, the Swallowtails, Apollos and Birdwings
- Family Pieridae, the Whites and Yellows
- Family Lycaenidae, the Blues and Coppers, also called the
- Family Riodinidae, the Metalmark butterflies
- Family Nymphalidae, the Brush-footed butterflies
The superfamily Hesperioidea comprises one family only, albeit a large one,
the skippers of family Hesperiidae, whereas the superfamily Hedyloidea
also consists of a single family Hedylidae with about 40 species.
A study combining morphological and molecular data concluded that Hesperiidae,
Papilionidae, Pieridae, Lycaenidae and Riodinidae could all be strongly
supported as monophyletic groups, but the monophyletic status of Nymphalidae is
uncertain. Lycaenidae and Riodinidae were confirmed as sister taxa, and
Papilionidae as the outgroup to the rest of the true butterflies, but the
location of Pieridae within the pattern of descent was unclear, with different
lines of evidence suggesting different conclusions. The data suggested that the
Hedyloidea are indeed more closely related to the butterflies than to other
Butterfly? feeding off a Butterfly Bush. USA
Some older classifications recognize additional families, for example
Danaidae, Heliconiidae, Libytheidae and Satyridae, but modern classifications
treat these as subfamilies within the Nymphalidae.
Butterflies and moths
The dichotomous classification of lepidopterans into butterflies and moths is
one that is popular but not used in taxonomy. The folk groups of butterflies and
moths can be distinguished using several features but there are exceptions to
most of these rules.
The four stages in the lifecycle of a butterfly
Unlike many insects, butterflies do not experience a nymph period, but
instead go through a pupal stage which lies between the larva and the adult
stage (the imago). Butterflies are termed as holometabolous insects, and
go through complete metamorphosis.
- Larva, known as a caterpillar
- Pupa (chrysalis)
- Adult butterfly (imago)
It is a popular belief that butterflies have very short life spans. However,
butterflies in their adult stage can live from a week to nearly a year depending
on the species. Many species have long larval life stages while others can
remain dormant in their pupal or egg stages and thereby survive winters.
Butterflies may have one or more broods per year. The number of generations
per year varies from temperate to tropical regions with tropical regions showing
a trend towards multivoltinism.
Butterfly eggs consist of a hard-ridged outer layer of shell, called the
chorion. This is lined with a thin coating of wax which prevents the egg
from drying out before the larva has had time to fully develop. Each egg
contains a number of tiny funnel-shaped openings at one end, called
micropyles; the purpose of these holes is to allow sperm to enter and
fertilize the egg. Butterfly and moth eggs vary greatly in size between species,
but they are all either spherical or ovate.
Butterfly eggs are fixed to a leaf with a special glue which hardens rapidly.
As it hardens it contracts, deforming the shape of the egg. This glue is easily
seen surrounding the base of every egg forming a meniscus. The nature of the
glue is unknown and is a suitable subject for research. The same glue is
produced by a pupa to secure the setae of the cremaster. This glue is so hard
that the silk pad, to which the setae are glued, cannot be separated.
Eggs are usually laid on plants. Each species of butterfly has its own
hostplant range and while some species of butterfly are restricted to just one
species of plant, others use a range of plant species, often including members
of a common family.
The egg stage lasts a few weeks in most butterflies but eggs laid close to
winter, especially in temperate regions, go through a diapause stage, and
the hatching may take place only in spring. Other butterflies may lay their eggs
in the spring and have them hatch in the summer. These butterflies are usually
northernly species (Mourning cloak, Tortoiseshells)
Larvae, or caterpillars, are multi-legged eating machines. They consume plant
leaves and spend practically all of their time in search of food. Although most
caterpillars are herbivorous, a few species such as Spalgis epius and
Liphyra brassolis are entomophagous (insect eating). Some larvae, especially
those of the Lycaenidae form mutual associations with ants. They communicate
with the ants using vibrations that are transmitted through the substrate as
well as using chemical signals.
The ants provide some degree of protection to these larvae and they in turn
gather honeydew secretions.
Caterpillars mature through a series of stages, called instars. Near the end
of each instar, the larva undergoes a process called apolysis, in which the
cuticle, a mixture of chitin and specialized proteins, is released from the
epidermis and the epidermis begins to form a new cuticle beneath. At the end of
each instar, the larva moults the old cuticle, and the new cuticle rapidly
hardens and pigments. Development of butterfly wing patterns begins by the last
Mating Common Buckeye
Butterfly caterpillars have three pairs of true legs from the thoracic
segments and up to 6 pairs of prolegs arising from the abdominal segments. These
prolegs have rings of tiny hooks called crochets that help them grip the
Some caterpillars have the ability to inflate parts of their head to appear
snake-like. Many have false eye-spots to enhance this effect. Some caterpillars
have special structures called osmeteria which are everted to produce smelly
chemicals. These are used in defense.
Host plants often have toxic substances in them and caterpillars are able to
sequester these substances and retain them into the adult stage. This helps
making them unpalatable to birds and other predators. Such unpalatibility is
advertised using bright red, orange, black or white warning colours. The toxic
chemicals in plants are often evolved specifically to prevent them from being
eaten by insects. Insects in turn develop countermeasures or make use of these
toxins for their own survival. This "arms race" has led to the coevolution of
insects and their host plants.
Wings or wing pads are not visible on the outside of the larva, but when
larvae are dissected, tiny developing wing disks can be found on the
second and third thoracic segments, in place of the spiracles that are apparent
on abdominal segments. Wing disks develop in association with a trachea that
runs along the base of the wing, and are surrounded by a thin peripodial
membrane, which is linked to the outer epidermis of the larva by a tiny
Wing disks are very small until the last larval instar, when they increase
dramatically in size, are invaded by branching tracheae from the wing base that
precede the formation of the wing veins, and begin to develop patterns
associated with several landmarks of the wing.
Near pupation, the wings are forced outside the epidermis under pressure from
the hemolymph, and although they are initially quite flexible and fragile, by
the time the pupa breaks free of the larval cuticle they have adhered tightly to
the outer cuticle of the pupa (in obtect pupae). Within hours, the wings form a
cuticle so hard and well-joined to the body that pupae can be picked up and
handled without damage to the wings.
When the larva is fully grown, hormones such as prothoracicotropic hormone (PTTH)
are produced. At this point the larva stops feeding and begins "wandering" in
the quest of a suitable pupation site, often the underside of a leaf.
The larva transforms into a pupa (or chrysalis) by anchoring itself to a
substrate and moulting for the last time. The chrysalis is usually incapable of
movement, although some species can rapidly move the abdominal segments or
produce sounds to scare potential predators.
Chrysalis of Gulf Fritillary
The pupal transformation into a butterfly through metamorphosis has held
great appeal to mankind. To transform from the miniature wings visible on the
outside of the pupa into large structures usable for flight, the pupal wings
undergo rapid mitosis and absorb a great deal of nutrients. If one wing is
surgically removed early on, the other three will grow to a larger size. In the
pupa, the wing forms a structure that becomes compressed from top to bottom and
pleated from proximal to distal ends as it grows, so that it can rapidly be
unfolded to its full adult size. Several boundaries seen in the adult color
pattern are marked by changes in the expression of particular transcription
factors in the early pupa.
Adult or Imago
The adult, sexually mature, stage of the insect is known as the imago. As
Lepidoptera, butterflies have four wings that are covered with tiny scales (see
photo). The fore and hindwings are not hooked together, permitting a more
graceful flight. An adult butterfly has six legs, but in the nymphalids, the
first pair is reduced. After it emerges from its pupal stage, a butterfly cannot
fly until the wings are unfolded. A newly-emerged butterfly needs to spend some
time inflating its wings with blood and letting them dry, during which time it
is extremely vulnerable to predators. Some butterflies wings may take up to 3
hours to dry while others take about 1 hour. Most butterflies and moths will
excrete excess dye after hatching. This fluid may be white, red, orange, or in
rare cases, blue.
1 - Antenna : 2 - Head : 3 - Compound eye : 4 -
Proboscis : 5 - Front leg : 6 - Middle leg : 7 - Thorax : 8 - Femur : 9 - Tibia
of a hind leg : 10 - Tarsus of a hind leg : 11 - Abdominal segment : 12 -
Abdomen : 13 - Hindwing : 14 - Spur or tail : 15 - Outer margin : 16 - Apex : 17
- Vein : 18 - forewing : 19 - Costal margin
Butterflies are characterized by their scale covered wings. The coloration of
butterfly wings is created by minute scales. These scales are pigmented with
melanins that give them blacks and browns, but blues, greens, reds and
iridescence are usually created not by pigments but the microstructure of the
scales. This structural coloration is the result of coherent scattering of light
by the photonic crystal nature of the scales.
Many adult butterflies exhibit polymorphism, showing differences in
appearance. These variations include geographic variants and seasonal forms. In
addition many species have females in multiple forms, often with mimetic forms.
Sexual dimorphism in coloration and appearance is widespread in butterflies. In
addition many species show sexual dimorphism in the patterns of ultraviolet
reflectivity, while otherwise appearing identical to the unaided human eye. Most
of the butterflies have a sex-determination system that is represented as ZW
with females being the heterogametic sex (ZW) and males homogametic (ZZ).
Genetic abnormalities such as gynandromorphy also occur from time to time. In
addition many butterflies are infected by Wolbachia and infection by the
bacteria can lead to the conversion of males into females
or the selective killing of males in the egg stage.
Batesian and Mullerian mimicry in butterflies is common. Batesian mimics
imitate other species to enjoy the protection of an attribute they do not share,
aposematism in this case. The Common Mormon of India has female morphs which
imitate the unpalatable red-bodied swallowtails, the Common Rose and the Crimson
Rose. Mullerian mimicry occurs when aposematic species evolve to resemble each
other, presumably to reduce predator sampling rates, the Heliconius butterflies
of the Americas being a good example.
The Heliconius butterflies from the tropics of
the Western Hemisphere are the classical model for Müllerian mimicry
Wing markings called eyespots are present in some species; these may have an
automimicry role for some species. In others, the function may be intraspecies
communication, such as mate attraction. In several cases, however, the function
of butterfly eyespots is not clear, and may be an evolutionary anomaly related
to the relative elasticity of the genes that encode the spots.
Many of the tropical butterflies have distinctive seasonal forms. This
phenomenon is termed seasonal polyphenism and the seasonal forms of the
butterflies are called the dry-season and wet-season forms. How the season
affects the genetic expression of patterns is still a subject of research.
Experimental modification by ecdysone hormone treatment has demonstrated that it
is possible to control the continuum of expression of variation between the wet
and dry-season forms. The
dry-season forms are usually more cryptic and it has been suggested that the
protection offered may be an adaptation. Some also show greater dark colours in
the wet-season form which may have thermoregulatory advantages by increasing
ability to absorb solar radiation.
Butterflies feed primarily on nectar from flowers. Some also derive
nourishment from pollen, tree sap, rotting fruit, dung, and dissolved minerals
in wet sand or dirt. Butterflies play an important ecological role as
As adults, butterflies consume only liquids and these are sucked by means of
their proboscis. They feed on nectar from flowers and also sip water from damp
patches. This they do for water, for energy from sugars in nectar and for sodium
and other minerals which are vital for their reproduction. Several species of
butterflies need more sodium than provided by nectar. They are attracted to
sodium in salt and they sometimes land on people, attracted by human sweat.
Besides damp patches, some butterflies also visit dung, rotting fruit or
carcasses to obtain minerals and nutrients. In many species, this Mud-puddling
behaviour is restricted to the males and studies have suggested that the
nutrients collected are provided as a nuptial gift along with the spermatophore
Butterflies sense the air for scents, wind and nectar using their antennae.
The antennae come in various shapes and colours. The hesperids have a pointed
angle or hook to the antennae, while most other families show knobbed antennae.
The antennae are richly covered with sensillae. A butterfly's sense of taste is
coordinated by chemoreceptors on the tarsi, which work only on contact, and are
used to determine whether an egg-laying insect's offspring will be able to feed
on a leaf before eggs are laid on it.
Many butterflies use chemical signals, pheromones, and specialized scent scales
(androconia) and other structures (coremata or 'Hair pencils' in the Danaidae)
are developed in some species.
Vision is well developed in butterflies and most species are sensitive to the
ultraviolet spectrum. Many species show sexual dimorphism in the patterns of UV
reflective patches. Color vision
may be widespread but has been demonstrated in only a few species.
Some butterflies have organs of hearing and some species are also known to
make stridulatory and clicking sounds.
Many butterflies, such as the Monarch butterfly, are migratory and capable of
long distance flights. They migrate during the day and use the sun to orient
themselves. They also perceive polarized light and use it for orientation when
the sun is hidden.
Many species of butterfly maintain territories and actively chase other
species or individuals that may stray into them. Some species will bask or perch
on chosen perches. The flight styles of butterflies are often characteristic and
some species have courtship flight displays. Basking is an activity which is
more common in the cooler hours of the morning. Many species will orient
themselves to gather heat from the sun. Some species have evolved dark wingbases
to help in gathering more heat and this is especially evident in alpine forms.
Like many other members of the insect world, the lift generated by
butterflies is more than what can be accounted for by steady-state,
non-transitory aerodynamics. Studies using Vanessa atalanta in a
windtunnel show that they use a wide variety of aerodynamic mechanisms to
generate force. These include wake capture, vortices at the wing edge,
rotational mechanisms and Weis-Fogh 'clap-and-fling' mechanisms. The butterflies
were also able to change from one mode to another rapidly.
(See also Insect flight)
Many butterflies migrate over long distances. Particularly famous migrations
being those of the Monarch butterfly from Mexico to North America, a distance of
about 4,000 to 4,800 kilometres (2500-3000 miles). Other well known migratory
species include the Painted Lady and several of the Danaine butterflies.
Spectacular and large scale migrations associated with the Monsoons are seen in
peninsular India. Migrations have
been studied in more recent times using wing tags and also using stable hydrogen
Butterflies have been shown to navigate using time compensated sun compasses.
They can see polarized light and therefore orient even in cloudy conditions. The
polarized light in the region close to the ultraviolet spectrum is suggested to
be particular important.
It is suggested that most migratory butterflies are those that belong to
semi-arid areas where breeding seasons are short.
The life-histories of their host plants also influence the strategies of the
Butterflies are threatened in their early stages by parasitoids and in all
stages by predators, diseases and environmental factors. They protect themselves
by a variety of means.
Butterfly Vanessa cardui
Chemical defenses are widespread and are often based on chemicals of plant
origin. In many cases the plants themselves have evolved these toxic substances
to reduce attack to them. These defense mechanisms are effective only if they
are also well advertised. Many unpalatable butterflies are brightly colored.
This has led to unprotected butterflies evolving forms that appear like the
unpalatable butterflies. These mimetic forms are usually restricted to the
Cryptic coloration is found in many butterflies. Some like the oakleaf
butterfly are remarkable imitations of leaves.
As caterpillars, many defend themselves by freezing and appearing like sticks or
branches. Some papilionid caterpillars resemble bird dropping in their early
instars. Some caterpillars have hairs and bristly structures that provide
protection while others are gregarious and form dense aggregations. Some species
also form associations with ants and gain their protection (See Myrmecophile).
Behavioural defenses include perching and wing positions to avoid being
conspicuous. Some female Nymphalid butterflies are known to guard their eggs
from parasitoid wasps.
Eyespots and tails are found in many lycaenid butterflies and these divert
the attention of predators from the more vital head region. An alternative
theory is that these cause ambush predators such as spiders to approach from the
wrong end and allow for early visual detection.
There are between 15,000 and 20,000 species of butterflies worldwide. Some
well known species from around the world include:
- Swallowtails and Birdwings, Family Papilionidae
- Common Yellow Swallowtail, Papilio machaon
- Spicebush Swallowtail, Papilio troilus
- Lime Butterfly, Papilio demoleus
- Ornithoptera genus (Birdwings; the largest butterflies)
- Whites or Yellows, Family Pieridae
- Small White, Pieris rapae
- Green-veined White, Pieris napi
- Common Jezebel, Delias eucharis
- Blues and Coppers or Gossamer-Winged Butterflies, Family Lycaenidae
- Xerces Blue, Glaucopsyche xerces (extinct)
- Karner Blue, Lycaeides melissa samuelis (endangered)
- Red Pierrot, Talicada nyseus
- Metalmark butterflies, Family Riodinidae
- Lange's Metalmark Butterfly
- Plum Judy, Abisara echerius
- Brush-footed butterflies, Family Nymphalidae
- Painted Lady, or Cosmopolite, Vanessa cardui
- Monarch butterfly, Danaus plexippus
- Morpho genus
- Speckled Wood, Pararge aegeria
Artistic depictions of butterflies have been used in many cultures including
Egyptian hieroglyphics 3500 years ago.
Today, butterflies are widely used in various objects of art.
According to the “Butterflies” chapter in Kwaidan: Stories and Studies of
Strange Things, by Lafcadio Hearn, a butterfly is seen as the
personification of a person's soul; whether they be living, dying, or already
dead. One Japanese superstition says that if a butterfly enters your guestroom
and perches behind the bamboo screen, the person whom you most love is coming to
see you. However, large numbers of butterflies are viewed as bad omens. 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.
The Russian word for butterflies, pronounced "bah' bch ka", it also means
"bow tie". It is a diminutive of "baba" or "babka" (= "woman, grandmother,
cake", whence also "babushka" = "grandmother" in English, "babushka" = "a
grandma-style headkerchief") and in Greek it means soul.
According to Mircea Eliade's Encyclopedia of Religion, some of the Nagas
of Manipur trace their ancestry from a butterfly.
In Chinese culture two butterflies flying together are a symbol of love. Also
a famous Chinese folk story called Butterfly Lovers. The Taoist philosopher
Zhuangzi once had a dream of being a butterfly flying without care about
humanity, however when he woke up and realised it was just a dream, he thought
to himself "Was I before a man who dreamt about being a butterfly, or am I now a
butterfly who dreams about being a man?"
In some old cultures, butterflies also symbolize rebirth into a new life
after being inside a cocoon for a period of time.
Some people say that when a butterfly lands on you it means good luck. The
idiom "butterflies in the stomach" is used to describe a state of nervousness.
Studies on the reflection of light by the scales on wings of swallowtail
butterflies have to led to the innovation of more efficient Light-emitting
The structural colouration of butterflies is inspiring nanotechnology
research to produce paints that do not use toxic pigments and in the development
of new display technologies.
|butterflies are awesome and