butterfly

Butterfly

mp to: navigation, search For other uses, see Butterfly (disambiguation)

mp to: navigation, search For other uses, see Butterfly (disambiguation). Page semi-protected Butterflies Temporal range: Eocene-Recent, 45–0 Ma PreЄ Є O S D C P T J K Pg N Charaxes brutus natalensis in Dar es Salaam, Tanzania Scientific classification Kingdom: Animalia Phylum: Arthropoda Class: Insecta Order: Lepidoptera (unranked): Rhopalocera Subgroups Superfamily Hedyloidea: Hedylidae Superfamily Hesperioidea: Hesperiidae Superfamily Papilionoidea: Papilionidae Pieridae Nymphalidae Lycaenidae Riodinidae A butterfly is a mainly day-flying insect of the order Lepidoptera, which includes the butterflies and moths. Like other holometabolous insects, the butterfly's life cycle consists of four parts: egg, larva, pupa and adult. Most species are diurnal. Butterflies have large, often brightly coloured wings, and conspicuous, fluttering flight. Butterflies comprise the true butterflies (superfamily Papilionoidea), the skippers (superfamily Hesperioidea) and the moth-butterflies (superfamily Hedyloidea). All the many other families within the Lepidoptera are referred to as moths. The earliest known butterfly fossils date to the mid Eocene epoch, between 40–50 million years ago.[1]

Butterflies exhibit polymorphism, mimicry and aposematism. Some, like the Monarch, will migrate over long distances. Some butterflies have evolved symbiotic and parasitic relationships with social insects such as ants. Some species are pests because in their larval stages they can damage domestic crops or trees; however, some species are agents of pollination of some plants, and caterpillars of a few butterflies (e.g., Harvesters) eat harmful insects. Culturally, butterflies are a popular motif in the visual and literary arts.

Eggs

Butterfly eggs are protected by 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 almost invariably 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 (resting) 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 northern species, such as the Mourning Cloak (Camberwell Beauty) and the Large and Small Tortoiseshell butterflies.[citation needed]

Mimicry

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 from the Americas beiHabitsng a good example. 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.

Habits

Butterflies feed primarily on nectar from flowers. Some also derive nourishment from pollen,[22] tree sap, rotting fruit, dung, decaying flesh, and dissolved minerals in wet sand or dirt. Butterflies are important as pollinators for some species of plants although in general they do not carry as much pollen load as bees. They are however capable of moving pollen over greater distances.[23] Flower constancy has been observed for at least one species of butterfly.

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 butterfliMigrationes 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.

Migration

Many butterflies migrate over long distances. Particularly famous migrations are those of the Monarch butterfly from Mexico to northern USA and southern Canada, a distance of about 4000 to 4800 km (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.[35] Migrations have been studied in more recent times using wing tags and also using stable hydrogen isotopes.[36][37] 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 particularly important.[38] It is suggested that most migratory butterflies are those that belong to semi-arid areas where breeding seasons are short.[39] The life-histories of their..

es. Many butterflies migrate over long distances. Particularly famous migrations are those of the Monarch butterfly from Mexico to northern USA and southern Canada, a distance of about 4000 to 4800 km (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.^[35] Migrations have been studied in more recent times using wing tags and also using stable hydrogen isotopes.
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 particularly important.
It is suggested that most migratory butterflies are those that belong to semi-arid ar 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 particularly important.
eas where breeding seasons are short. The life-histories of their host plants also influence the strategies of

It is suggested that most migratory butterflies are those that belong to semi-arid areas where breeding seasons are short.[39] The life-histories of their host plants also influence the strategies of the butterflies.[40]

It is suggested that most migratory butterflies are those that belong to semi-arid areas where breeding seasons are shot...

Defense

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 mostly based on chemicals of plant origin. In many cases the plants themselves evolved these toxic substances as protection against herbivores. Butterflies have evolved mechanisms to sequester these plant toxins and use them instead in their own defense.[41] These defense mechanisms are effective only if they are also well advertised and this has led to the evolution of bright colours in unpalatable butterflies. This signal may be mimicked by other butterflies. These mimetic forms are usually restricted to the females.

Life cycle and foodplants

The eggs are laid singularly on a wide range of foodplants including Hedge mustard Sisybrium officinale Garlic Mustard Alliaria petiolata, Cuckooflower Cardamine pratense, Water-cress Rorippa nastutium-aquaticum, Charlock Sinapis arvensis, Large bitter-cress Cardamine amara, wild cabbage Brassica oleracea and wild Radish Raphanus raphanistrum and so it is rarely a pest in gardens. The caterpillar is green and well camouflaged. It is often found feeding on the same plant as the Orange Tip but never competes for food because it only feeds on the leaves whereas the Orange Tip caterpillar feeds on the flowers and developing seed pods. Like other Pieris spp. it overwinters as a pupa. Habitat

Habitat

Pieris napi is found in damp, grassy places with some shade, forest edges, hedgerows, meadows and wooded river valleys. The later generations, widen their catchment areas in the search for alternative forage crops in drier, but flowery places . In the Mediterranean the insect is also found in scrub around mountain streams or springs and on floodplains with Nasturtium officinale. It is found from sea level to high altitude (2500m. in Central Europe centrale, 2600 m in Italy).