Clouded Yellow
Encyclopedia
Colias croceus is a small butterfly
of the Pieridae
family, that is, the Yellows and Whites. In India and nearby regions it is known as the Dark Clouded Yellow or Common Clouded Yellow to distinguish it from the other species of clouded yellow
s occurring there; elsewhere it is often simply known as "the clouded yellow".
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The upperside is golden to orange yellow with a broad black margin on all four wings and a black spot near the center forewing. The underside lacks the black borders and is lighter, with a more greenish tint, particularly on the forewings. In the forewing underside is the same dark spot as on the upperside, but often with a light center; the hindwing underside has a white center spot, often with a smaller white or dark dot immediately above it. Sometimes, a row of black dots occurs on the underwings' outer margins, corresponding to where the black border ends on the upperside,
Females differ from the males in having yellow spots along the black borders on the upperside. In a small proportion of females the golden upperside colouration is replaced by a pale cream colour. These have been distinguished as form helice, but do not seem to be that distinct as intermediates exist and the variation is to some extent related to humidity
during development, with dryer conditions producing paler coloration.
In flight, it is easily identifiable by the intense yellow colouring, much brighter than that of the lemon-yellow male Common Brimstone which also lacks black color. Like all Colias
species they never open their wings at rest. Pale females can be confused with the rarer Pale Clouded Yellow
(C. hyale) and Berger's Clouded Yellow (C. sareptensis). Even the palest C. croceus tends to have more black on the upperside however, in particular on the hindwings.
and southern Europe
and eastwards through Turkey
into the Middle East
but it occurs throughout much of Europe
as a summer migrant, in good years individuals reaching Scandinavia
. In Asia
, its range extends into central Siberia
in the north and barely into India
in the south; it is not found in Central Asia
. In the UK they can be seen on the south coast almost every year in varying numbers, and regularly breed there. Occurrence in the rest of the UK varies considerably from year to year, but they are increasingly observed as far north as Dumfries
and Galloway
.
A truly migratory European butterfly, this species is famous for occasional mass migrations and subsequent breeding, which are often referred to in the United Kingdom
as "clouded yellow years". Notable clouded yellow years include 1877, 1947, 1983, 1992, 1994, 1996 and 2000.
s grow fast in warm weather, sometimes pupa
ting within a month. Pupation lasts for two or three weeks and in good years there can be as many as three generation
s per year, with adults still on the wing at the beginning of November.
Common Clouded Yellows feed on a variety of leguminous plants, namely Faboideae
. In the UK wild and cultivated clover
s (Trifolium) and Alfalfa
(Medicago sativa) are favourites; less frequently, Common Bird's-foot Trefoil Lotus corniculatus
is eaten.
Butterfly
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...
of the Pieridae
Pieridae
The Pieridae are a large family of butterflies with about 76 genera containing approximately 1,100 species, mostly from tropical Africa and Asia. Most pierid butterflies are white, yellow or orange in coloration, often with black spots...
family, that is, the Yellows and Whites. In India and nearby regions it is known as the Dark Clouded Yellow or Common Clouded Yellow to distinguish it from the other species of clouded yellow
Clouded Yellow
Colias croceus is a small butterfly of the Pieridae family, that is, the Yellows and Whites. In India and nearby regions it is known as the Dark Clouded Yellow or Common Clouded Yellow to distinguish it from the other species of clouded yellows occurring there; elsewhere it is often simply known as...
s occurring there; elsewhere it is often simply known as "the clouded yellow".
Description
Females differ from the males in having yellow spots along the black borders on the upperside. In a small proportion of females the golden upperside colouration is replaced by a pale cream colour. These have been distinguished as form helice, but do not seem to be that distinct as intermediates exist and the variation is to some extent related to humidity
Humidity
Humidity is a term for the amount of water vapor in the air, and can refer to any one of several measurements of humidity. Formally, humid air is not "moist air" but a mixture of water vapor and other constituents of air, and humidity is defined in terms of the water content of this mixture,...
during development, with dryer conditions producing paler coloration.
In flight, it is easily identifiable by the intense yellow colouring, much brighter than that of the lemon-yellow male Common Brimstone which also lacks black color. Like all Colias
Colias
Colias is a genus of butterflies in the family Pieridae. They are usually called clouded yellows; the North American name "sulphurs" is elsewhere used for Coliadinae in general. The closest living relative is the genus Zerene, which is sometimes included in Colias.This genus occurs throughout the...
species they never open their wings at rest. Pale females can be confused with the rarer Pale Clouded Yellow
Pale Clouded Yellow
Pale Clouded Yellow is a small butterfly of the Family Pieridae, that is, the Yellows and Whites, which is found in most of Europe and large parts of Asia.-References:* Evans, W.H. The Identification of Indian Butterflies...
(C. hyale) and Berger's Clouded Yellow (C. sareptensis). Even the palest C. croceus tends to have more black on the upperside however, in particular on the hindwings.
Distribution and ecology
The Common Clouded Yellow's breeding range is North AfricaNorth Africa
North Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa. Geopolitically, the United Nations definition of Northern Africa includes eight countries or territories; Algeria, Egypt, Libya, Morocco, South Sudan, Sudan, Tunisia, and...
and southern Europe
Southern Europe
The term Southern Europe, at its most general definition, is used to mean "all countries in the south of Europe". However, the concept, at different times, has had different meanings, providing additional political, linguistic and cultural context to the definition in addition to the typical...
and eastwards through Turkey
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...
into the Middle East
Middle East
The Middle East is a region that encompasses Western Asia and Northern Africa. It is often used as a synonym for Near East, in opposition to Far East...
but it occurs throughout much of Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
as a summer migrant, in good years individuals reaching Scandinavia
Scandinavia
Scandinavia is a cultural, historical and ethno-linguistic region in northern Europe that includes the three kingdoms of Denmark, Norway and Sweden, characterized by their common ethno-cultural heritage and language. Modern Norway and Sweden proper are situated on the Scandinavian Peninsula,...
. In Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
, its range extends into central Siberia
Siberia
Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...
in the north and barely into India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
in the south; it is not found in Central Asia
Central Asia
Central Asia is a core region of the Asian continent from the Caspian Sea in the west, China in the east, Afghanistan in the south, and Russia in the north...
. In the UK they can be seen on the south coast almost every year in varying numbers, and regularly breed there. Occurrence in the rest of the UK varies considerably from year to year, but they are increasingly observed as far north as Dumfries
Dumfries
Dumfries is a market town and former royal burgh within the Dumfries and Galloway council area of Scotland. It is near the mouth of the River Nith into the Solway Firth. Dumfries was the county town of the former county of Dumfriesshire. Dumfries is nicknamed Queen of the South...
and Galloway
Galloway
Galloway is an area in southwestern Scotland. It usually refers to the former counties of Wigtownshire and Kirkcudbrightshire...
.
A truly migratory European butterfly, this species is famous for occasional mass migrations and subsequent breeding, which are often referred to in the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
as "clouded yellow years". Notable clouded yellow years include 1877, 1947, 1983, 1992, 1994, 1996 and 2000.
Life cycle and larval host plants
In southern Europe and North Africa they breed continuously throughout the year. Eggs are laid singly on foodplant leaves. The caterpillarCaterpillar
Caterpillars are the larval form of members of the order Lepidoptera . They are mostly herbivorous in food habit, although some species are insectivorous. Caterpillars are voracious feeders and many of them are considered to be pests in agriculture...
s grow fast in warm weather, sometimes pupa
Pupa
A pupa is the life stage of some insects undergoing transformation. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, going through four life stages; embryo, larva, pupa and imago...
ting within a month. Pupation lasts for two or three weeks and in good years there can be as many as three generation
Generation
Generation , also known as procreation in biological sciences, is the act of producing offspring....
s per year, with adults still on the wing at the beginning of November.
Common Clouded Yellows feed on a variety of leguminous plants, namely Faboideae
Faboideae
Faboideae is a subfamily of the flowering plant family Fabaceae or Leguminosae. One acceptable alternative name for the subfamily is Papilionoideae....
. In the UK wild and cultivated clover
Clover
Clover , or trefoil, is a genus of about 300 species of plants in the leguminous pea family Fabaceae. The genus has a cosmopolitan distribution; the highest diversity is found in the temperate Northern Hemisphere, but many species also occur in South America and Africa, including at high altitudes...
s (Trifolium) and Alfalfa
Alfalfa
Alfalfa is a flowering plant in the pea family Fabaceae cultivated as an important forage crop in the US, Canada, Argentina, France, Australia, the Middle East, South Africa, and many other countries. It is known as lucerne in the UK, France, Australia, South Africa and New Zealand, and known as...
(Medicago sativa) are favourites; less frequently, Common Bird's-foot Trefoil Lotus corniculatus
Lotus corniculatus
Lotus corniculatus is a common flowering plant native to grassland temperate Eurasia and North Africa. The common name is Bird's-foot Trefoil , though the common name is often also applied to other members of the genus...
is eaten.
See also
- List of butterflies of India (Pieridae)
- List of butterflies of Great Britain