Home | Hobbies | Books | Mutiara Laut | Website Projects | Links

Bali Impressions

Previous • Quick Search on pictures

Animals in and around your house or Hotel

Butterflies,  Lepidoptera,  Kupu kupu


A butterfly is a insect of the order Lepidoptera,
They are notable for their unusual life cycle with a larval caterpillar stage, an inactive pupal stage and a spectacular metamorphosis into a familiar and colourful winged adult form.
The diverse patterns formed by their brightly coloured wings and their erratic-yetgraceful flight have made butterfly watching a popular hobby.
The Old English word for butterfly was buttorfleoge apparently because butterflies were thought to steal milk.
A similar word occurs in Dutch and German originating from the same belief.
This is believed to have led to the evolution of its present name form - butterfly.

The five families of true butterflies usually recognized in theer            Schmetterlingsjager (The butterfly hunter) by Carl Spitzweg (1840)
Papilionoidea are:
* Family Papilionidae, the Swallowtails and Birdwings
* Family Pieridae, the Whites and Yellows
* Family Lycaenidae, the Blues and Coppers, also called the Gossamer-Winged Butterflies
* Family Riodinidae, the Metalmark butterflies
* Family Nymphalidae, the Brush-footed butterflies.

The four stages in the lifecycle of a butterfly:
* Egg * 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 and egg
stages and thereby survive winters.
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 are restricted to just one species, others use a range of plant species,
often 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
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 mutualistic 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 larval instar.
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 substrate.
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 evolutionary arms race has lead to
coevolution in the insects and their host plants.
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 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 subtrate 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.
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.
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 ,but, unlike moths, 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.
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 pollinators.
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 behaviour is
restricted to the males and studies have suggested that the nutrients collected are provided
as a nuptial gift along with the spermatophore during mating.
Butterflies sense the air for scents, wind and nectar using their antennae. The antennae
come in various shapes and colours.The antennae are richly covered with sensillae. Chemoreceptors
are also present on the tarsi and these work only on contact. Many butterflies use
chemical signals, pheromones, and specialized scent scales (androconia) .
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.
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 commoner 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. 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. 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 females. 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.


Previous • Quick Search on pictures