Euploea core
Encyclopedia
The Common Crow (Euploea core) is a common butterfly found in South Asia
South Asia
South Asia, also known as Southern Asia, is the southern region of the Asian continent, which comprises the sub-Himalayan countries and, for some authorities , also includes the adjoining countries to the west and the east...

. In India it is also sometimes referred to as the Common Indian Crow, and in Australia as the Australian Crow. It belongs to the Crows and Tigers subfamily of the Nymphalidae
Nymphalidae
The Nymphalidae is a family of about 5,000 species of butterflies which are distributed throughout most of the world. These 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...

 (Brushfooted butterflies).

The Common Crow is the most common representative of its genus Euploea. Like the Tigers (genus Danaus
Danaus (genus)
Danaus, commonly called Tigers, Milkweeds, Monarchs, and Queens, is a genus of butterflies in the tiger butterfly tribe. They are found worldwide, including North America, South America, Africa, Asia, Indonesia and Australia...

), the Crows are inedible and thus mimicked by other Indian butterflies (see Batesian mimicry
Batesian mimicry
Batesian mimicry is a form of mimicry typified by a situation where a harmless species has evolved to imitate the warning signals of a harmful species directed at a common predator...

). In addition, the Indian species of the Euploea genus shows another kind of mimicry, Müllerian mimicry
Müllerian mimicry
Müllerian mimicry is a natural phenomenon when two or more harmful species, that may or may not be closely related and share one or more common predators, have come to mimic each other's warning signals...

. Accordingly, this species has been studied in greater detail than other members of its genus in India.

Description

The Common Crow (Euploea core) is a glossy black butterfly with brown underside with white marks along the outer margins of the wing. The wingspan is about 8-9 cm and the body also has prominent white spots.

Upperside dark brown, broadly paler along terminal margins; Fore and hind wing with subterminal and terminal series of white spots; on fore wing the former more or less oval, curved inwards opposite apex, the latter series often incomplete, not reaching apex, the spots smaller; often there is a small costal spot, and very rarely a spot in apex of cell and one or more discal spots; on the hind wing the inner series of spots are elongate, the outer conical. Underside similar, but ground-colour more uniform; cell, costal and discal spots on both fore and hind wing nearly always present.

Race godarti (=E. godarti) (Northeast India and Myanmar)
Fore wing subtriangular, tornus more rounded than in E. core. Hindwing broadly ovate. Upperside dark brown, broadly paler along the terminal margins, especially on the fore wing. Fore wing with more or less incomplete and obsolescent series of subterminal and terminal small white spots, and a powdering of violaceous-white scales at apex, varying very considerably in extent from a mere trace of violaceous between the veins to a large and very conspicuous patch occupying the whole of the apex. Hind wing with a subterminal series of oval or inwardly conical and terminal series of more rounded white spots. Underside paler brown, the white spots larger, more clearly defined. Fore wing not violaceous at apex, a spot (sometimes absent) in apex of cell, and two or three discal spots. Hindwing: a spot in apex of cell, also sometimes absent, and a discal series of five small spots beyond. Antennae, head, thorax and abdomen very dark brown, and, the antennae excepted, sparsely spotted with white.

Taxonomy

The Common Crow has three races:
  • Race vermiculata : (India) UPF spots increase in size towards the apex.
  • Race core : (North India) These spots are more or less equal or reduce in size.
  • Race asela : (Sri Lanka) These spots are very small and the terminal spots vanish to the apex.

Habitat

It is found everywhere in India right up into the mountains till 8000 feet. Occasionally it swarms in the low, wet, jungles of South India due to the abundance of its foodplants which are spread over three orders of plants.

Habits

The butterfly, being protected by its inedibility, has a leisurely flight. It is often seen flying about shrubs and bushes in search of its host plants. It visits a large variety of flowering plant species.
On hot days large numbers of these butterflies can be seen mud-puddling
Mud-puddling
Mud-puddling is the phenomenon mostly seen in butterflies and involves their aggregation on substrates like wet soil, dung and carrion to obtain nutrients such as salts and amino acids. This behaviour has also been seen in some other insects, notably the leafhoppers.Lepidoptera are diverse in...

 on wet sand. This butterfly also gathers on damaged parts of plants such as Crotalaria
Crotalaria
Crotalaria is a genus of herbaceous plants and woody shrubs in the Family Fabaceae commonly known as rattlepods. Some 600 or more species of Crotalaria are described worldwide, mostly from the tropics; at least 500 species are known from Africa. Some species of Crotalaria are grown as ornamentals...

, Heliotropium
Heliotropium
Heliotropium is a genus of flowering plants in the borage family, Boraginaceae. There are 250 to 300 species in this genus, which are commonly known as heliotropes ....

to forage for chemicals precursors to produce pheromones.

Along with other Danaids
Danaus (genus)
Danaus, commonly called Tigers, Milkweeds, Monarchs, and Queens, is a genus of butterflies in the tiger butterfly tribe. They are found worldwide, including North America, South America, Africa, Asia, Indonesia and Australia...

 such as the Tigers, the Common Crow is one of the most common migrating butterfly species. Males and females in equal proportions have been seen to migrate.

Protection

The Common Crow is distasteful due to chemicals extracted from the latex of the food plants consumed in their caterpillar stage. Thus protected, they fly in a leisurely manner, gliding skillfully with wings held slightly above the horizontal. This indicates its protection due to inedibility to a predator. The inexperienced predator will try attacking it, but will learn soon enough to avoid this butterfly as the alkaloids in its body cause vomiting.

The butterfly has tough, leather
Leather
Leather is a durable and flexible material created via the tanning of putrescible animal rawhide and skin, primarily cattlehide. It can be produced through different manufacturing processes, ranging from cottage industry to heavy industry.-Forms:...

y wings. When attacked it shams death and oozes liquid which causes any predators to release them. The butterfly thus has the ability to recover 'miraculously' after the predator thinks it has been killed.

Mimicry

The protection mechanisms of the Common Crow, as of the other Danaids, and indeed of all unpalatable butterflies, result in predators learning this memorable aspect at first hand. Predators soon learn to associate the patterns and habits of the butterfly species with unpalatability and to avoid ingesting them in future.

This advantage of protection has led to a number of edible butterfly species, referred to as the mimic, evolving to resemble the inedible butterfly, which is referred to as the model. The resemblance is not only in butterfly markings, but also in behavioural and flight patterns. This form of mimicry where an edible species mimics an inedible species is called as Batesian mimicry
Mimic
In evolutionary biology, mimicry is the similarity of one species to another which protects one or both. This similarity can be in appearance, behaviour, sound, scent and even location, with the mimics found in similar places to their models....

.

The mimics can resemble the models very closely. In some cases, it requires hand examination and reference to field guides to tell them apart. The Common Crow is a good example, being mimicked by the following butterflies:
  • Common Mime, Papilio clytia form dissimilis, both male and female.
  • Malabar Raven, Papilio dravidarum
    Papilio dravidarum
    The Malabar Raven is a species of Swallowtail butterfly found in the Western Ghats of India.-Range:Endemic to the Western Ghats in South India. It occurs in the states of Kerala, Tamil Nadu, Karnataka and Goa.-Status:...

    , both male and female.
  • Common Raven, Papilio castor
    Papilio castor
    The Common Raven is a species of swallowtail butterfly found in South Asia.-Description:Male has the upper wings black, more or less irrorated with yellowish-brown scales that form on the fore wing somewhat indistinct longitudinal cell-lines and internervular streaks...

    , female.
  • Great Eggfly, Hypolimnas bolina
    Hypolimnas bolina
    The Great Eggfly , also called the Blue Moon Butterfly in New Zealand or Common Eggfly, is a species of nymphalid butterfly.-Race bolina:...

    , female.
  • Ceylon Palmfly, Elymnias singala male and female. (Not in India).


The genus Euploea also exhibits Müllerian mimicry
Mimic
In evolutionary biology, mimicry is the similarity of one species to another which protects one or both. This similarity can be in appearance, behaviour, sound, scent and even location, with the mimics found in similar places to their models....

. In this form of mimicry, the members of an inedible group of butterflies find it to their advantage to resemble one another so that their recognition by possible enemies is much easier. Besides this genus, the Blue Tigers (of the genus Danaus
Danaus (genus)
Danaus, commonly called Tigers, Milkweeds, Monarchs, and Queens, is a genus of butterflies in the tiger butterfly tribe. They are found worldwide, including North America, South America, Africa, Asia, Indonesia and Australia...

) also exhibit this form of mimicry in India.

Eggs

Eggs are laid on the underside of young leaves of the host plants. The egg is shiny white, tall and pointed, with ribbed sides. Just before hatching the eggs turn greyish with a black top.

Caterpillar

Throughout its life the caterpillar stays on the underside of the leaves. The caterpillar is cylindrical, vividly coloured and smooth. It has alternate white and dark brown or black transverse bands. Just above the legs and proleg
Proleg
A Proleg is the small fleshy, stub structure found on the ventral surface of the abdomen of most larval forms of insects of the order Lepidoptera, though they can also be found on other larval insects such as sawflies and a few types of flies....

s, along the entire body is a wide orangish-red band and the head is striped black and white. The caterpillar bears four tentacle-like appendages, three towards the front and one at the back. All of them are curved backward at the tips.
Since the host plants contain poisonous latex, the caterillar has evolved peculiar eating habits. It first chews the midrib of the leaf, cutting of its supply of latex and then goes on to nip a few of the secondary veins of the leaf, further blocking the flow of latex. Subsequently the caterpillar feeds on the leaf but only where the leaf's natural defences have been turned off. The caterpillar is able to tolerate the plant toxins and stores it in its fatty tissue and helps make the adult distasteful to predators.

The caterpillar is uniformly cylindrical. Its body is covered with bands of black and white interspersed with thick, yellow, dorsolateral spots. The most striking characteristics are the 3 pairs of long and black tentacles. The first pair is moveable and also the longest. The tentacles are present on the 3rd, 6th and 12th segments. The head is shiny, smooth and has alternating black and white semicircular bands. The legs and prolegs are black and the prolegs have white bands at their bases.

Pupa

The pupa of this species is shiny golden in color. The wing margins are marked with broad colorless bands. The abdomen has a row of black spots on each segment. The cremaster is black. The pupa later turns black.

Larval food plants

The Common Crow feeds on a large number of plants of the families Apocynaceae
Apocynaceae
The Apocynaceae or dogbane family is a family of flowering plants that includes trees, shrubs, herbs, and lianas.Many species are tall trees found in tropical rainforests, and most are from the tropics and subtropics, but some grow in tropical dry, xeric environments. There are also perennial herbs...

(Dogbanes and Oleanders), Asclepiadaceae
Asclepiadaceae
According to APG II, the Asclepiadaceae is a former plant family now treated as a subfamily in the Apocynaceae...

(Milkweeds), Moraceae
Moraceae
Moraceae — often called the mulberry family or fig family — are a family of flowering plants comprising about 40 genera and over 1000 species. Most are widespread in tropical and subtropical regions, less so in temperate climates...

(Figs), Rubiaceae
Rubiaceae
The Rubiaceae is a family of flowering plants, variously called the coffee family, madder family, or bedstraw family. The group contains many commonly known plants, including the economically important coffee , quinine , and gambier , and the horticulturally valuable madder , west indian jasmine ,...

, Ulmaceae
Ulmaceae
Ulmaceae is a family of flowering plant that includes the elms , and the zelkovas . Members of the family are widely distributed throughout the north temperate zone, and have a scattered distribution elsewhere except for Australasia.The family was formerly sometimes treated to include the...

(Nettles) and the specific species are Aphananthe cuspidata, Asclepias curassavica
Asclepias curassavica
Asclepias curassavica, commonly called Mexican Butterfly Weed, Blood-flower, Scarlet Milkweed or, Tropical Milkweed, is a species of flowering plant in the dogbane family, Apocynaceae. It is native to the American tropics....

, Asclepias guadeloupe, Asclepias syriaca, Calotropis gigantea
Calotropis gigantea
Calotropis gigantea is a species of Calotropis native to Indonesia, Malaysia, Philippines, Thailand, Sri Lanka, India and China....

, Carissa ovata
Carissa ovata
Carissa spinarum, the Conkerberry or Bush Plum, is a large shrub of the dogbane family , widely distributed in tropical regions around the Indian Ocean. It is most well known in Australia, where it is also called Currant Bush or, more ambiguously, "native currant" or even "black currant"...

, Cerbera manghas
Cerbera manghas
Cerbera manghas is a small evergreen coastal tree growing up 12 m tall. The shiny dark-green leaves are alternate, ovoid in shape. The flowers are fragrant, possessing a white tubular 5 lobed corolla about 3 to 5 cm in diameter, with a pink to red throat. They have 5 stamens and the ovary is...

, Cryptolepis pauciflora, Cryptolepis sinensis
Cryptolepis sinensis
Cryptolepis sinensis is a plant species in the genus Cryptolepis.C. sinensis is one of the food sources for the common crow , a common butterfly found in South Asia.-References:...

, Cryptostegia madagascariensis, Cynanchum carnosum, Ficus benghalensis
Ficus benghalensis
Ficus benghalensis, the banyan, is a large and extensive growing tree of the Indian subcontinent. Ficus benghalensis produces propagating roots which grow downwards as aerial roots. Once these roots reach the ground, they grow into woody trunks that can become indistinguishable from the main...

, Ficus benjamina, Ficus hederacea, Ficus microcarpa
Ficus microcarpa
Ficus microcarpa, also known as Chinese Banyan, Malayan Banyan, Indian Laurel or Curtain fig, is a banyan native in the range from Sri Lanka to India, southern China, the Malay Archipelago, the Ryukyu Islands, Australia, and New Caledonia.-Taxonomy:Hill's Weeping Fig is a form of Ficus microcarpa...

, Ficus muelleri, Ficus obliqua
Ficus obliqua
Ficus obliqua, commonly known as the Small-leaved Fig, a tree in the family Moraceae native to eastern Australia. It is a banyan of the genus Ficus which contains around 750 species worldwide in warm climates, including the edible fig...

, Ficus pandurata, Ficus platypoda
Ficus platypoda
Ficus platypoda, commonly known as the desert fig or rock fig, is a fig that is endemic to central and northern Australia, and Indonesia. The fruit can be eaten when soft and ripe. Horticulturally, it is suitable for use in bonsai; its tendency to form a wide trunk base and small leaves being...

, Ficus pyriformis, Ficus racemosa, Ficus religiosa, Ficus rubiginosa, Ficus variolosa, Gomphocarpus fruticosus, Gymnanthera oblonga, Hemidesmus indicus
Hemidesmus indicus
Indian Sarsaparilla is a species of plant that is found in South Asia. It is a slender, laticiferous, twining, sometimes prostrate or semi-erect shrub. Roots are woody and aromatic. The stem is numerous, slender, terete, thickened at the nodes...

, Holarrhena pubescens, Hoya australis
Hoya australis
Hoya australis, commonly known as the Waxvine or Common waxflower, is one of the species in the genus Hoya. It is a vine found on rainforest margins and rocky areas, and occurs in eastern and northern Australia, from the Northern Territory though coastal Queensland from Cape York to northern New...

, Ichnocarpus frutescens
Ichnocarpus frutescens
Ichnocarpus frutescens is a species of flowering plant in the dogbane family known by the English common name black creeper. It is native to much of China, India, Southeast Asia, and northern Australia...

, eichardtia australis, Marsdenia leichhardtiana, Marsdenia rostrata
Marsdenia rostrata
Marsdenia rostrata, the Milk Vine is a common climbing plant found in eastern, Australia. This member of the Dogbane family features white milky sap, when leaves are broken from the stem. It is found in a variety of habitats in relatively high rainfall areas, including rainforest and wet eucalyptus...

, Marsdenia suaveolens
Marsdenia suaveolens
Marsdenia suaveolens, the Sweet Scented Doubah is a small vine found in New South Wales, Australia. It is found in a variety of habitats in relatively high rainfall areas, from Bega to Port Macquarie. The original specimen was collected at Sydney in 1802.The specific epithet suaveolens is from...

, Nerium indicum, Nerium oleander, Parsonsia alboflavescens, Parsonsia straminea
Parsonsia straminea
Parsonsia straminea is a woody vine of the dogbane family, Apocynaceae. It occurs in the states of New South Wales and Queensland in Australia....

, Plumeria acuminata, Sarcostemma australe, Secamone elliptica, Streblus asper, Streblus asper, Toxocarpus wightianus, Trachelospermum bowringii and Tylophora indica

It usually has some preference for certain species in a given area. The more commonly used plants are Ficus racemosa, Nerium oleander, Nerium odorum and Cryptolepis buchananii. Ficus pumila
Ficus pumila
Ficus pumila is a woody evergreen vine that is native to East Asia.This plant requires the fig wasp Blastophaga pumilae for pollination, and is fed upon by larvae of the butterfly Marpesia petreus....

a cultivated garden plant which climbs on walls has also been noted.

Further reading

  • Evans, W.H. (1932) The Identification of Indian Butterflies. (2nd Ed), Bombay Natural History Society, Mumbai, India
  • Gaonkar, Harish (1996) Butterflies of the Western Ghats, India (including Sri Lanka) - A Biodiversity Assessment of a threatened mountain system. Journal of the Bombay Natural History Society.
  • Gay,Thomas; Kehimkar,Isaac & Punetha,J.C.(1992) Common Butterflies of India. WWF-India and Oxford University Press, Mumbai, India.
  • Kunte,Krushnamegh (2005) Butterflies of Peninsular India. Universities Press.
  • Wynter-Blyth, M.A. (1957) Butterflies of the Indian Region, Bombay Natural History Society, Mumbai, India.
  • Arun, P. R. (2000) Seasonality and abundance of insects with special reference to butterflies (Lepidoptera: Rhopalocera) in a Moist deciduous forest of Siruvani, Nilgiri Biosphere Reserve, SouthIndia Ph.D Thesis, Bharathiar University, Coimbatore. 236p

See also

  • Mimic
    Mimic
    In evolutionary biology, mimicry is the similarity of one species to another which protects one or both. This similarity can be in appearance, behaviour, sound, scent and even location, with the mimics found in similar places to their models....

  • Nymphalidae
    Nymphalidae
    The Nymphalidae is a family of about 5,000 species of butterflies which are distributed throughout most of the world. These 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...

  • List of butterflies of India
  • List of butterflies of India (Nymphalidae)

External links



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