Steven Cheshire's British Butterflies
British Butterflies: Species: Species Account - The Common Blue:
Common Blue
Polyommatus icarus (Rottemburg, 1775)

Common Blue egg.
  Common Blue caterpillar.
  Common Blue chrysalis
Common Blue
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Insecta: Lepidoptera : Family Lycaenidae: Subfamily Lycaeninae : Genus Polyommatus: Species icarus:
Double broods occur in England Wales and Ireland and butterflies can be seen between May - June and August - September. Partial 3rd broods may occur in good years. Single broods occur north of Derbyshire in England Scotland and parts of Northern Ireland with adults on the wing between June and September. Partial 2nd broods may occur in good years.

The bright blue males are most easily seen while the females are more secretive in behavior.

Counting and recording of Common Blues can be quite easy. The best time to make accurate counts of numbers within a colony is to visit the site late in the evening or during sunset. With experience and a good eye most individuals can be found usually resting on a dried grass stem facing down wings closed but one side face on to the sun to absorb as much heat as possible before the sun finally sets.
The Common Blue is found in a variety of grassy habitats particularly where the larval foodplants can be found in sunny sheltered positions. Many habitats are used including road verges woodland clearings disused railway lines quarries and coastal areas.
The Common Blue can be found across much of England and Wales and parts of Southern Scotland. The Common Blue is the most widespread butterfly in the UK but may only be found in substantial numbers where a breeding colony in favourable environmental conditions can be found.
Where to see the Common Blue in the British Isles
Other notes
Both the female and male Common Blue's are very variable in terms of coloration and some examples are very striking even within the same colony. The females in particular can be almost completely brown or blue with brown edges to the upperside of the wings. In Western Ireland and Scotland females are almost completely blue.
Lifecycle chart
Flight chart
The lifecycle and flight charts should be regarded as approximate guides to the Common Blue in Britain. Specific lifecycle states, adult emergence and peak flight times vary from year to year due to variations in weather conditions.
IUCN category status 2010 5   IUCN category status 2007 34
--awaiting data-- --awaiting data--

5Fox, R., Warren, M., Brereton, T. M., Roy, D. B. & Robinson, A.
(2010) A new Red List of British Butterflies. Insect Conservation and Diversity.
Least Concern Least Concern

3Fox, R., Warren, M & Brereton, T.
(2007) New Red List of British Butterflies. Butterfly Conservation, Wareham.

4More information about IUCN categories.
UK status
Larval foodplants
The larvae feed on a variety of plants including Common Bird's-foot-trefoil (Lotus corniculatus) Black Medick (Medicago lupulina) White Clover (Trifolium repens) and Lesser Trefoil (Trifolium dubium).

The larvae are difficult to find on the food plant however locating the eggs is easier being white and laid on the upper surfaces of the leaves.
British subspecies
Polyommatus icarus ssp. icarus (Rottemburg, 1775)
Occurs in southern and central England, Wales and Scotland.
Polyommatus icarus ssp. mariscolore (Kane, 1893)
Occurs in Ireland where it is common.The female is generally larger, with extensive blue colouration and larger, brighter orange marginal spots compared to that of the ssp. icarus.
Butterflies of Britain ID Chart
Your personal guide to British Butterflies. This 8-panel laminated chart is designed for speedy butterfly identification in the field. Ideal for anyone interested in identifying butterflies, perfect for children and adults and ideal for outdoor use, laminated, shower-proof and robust. Get your copy today.
Butterflies of Britain (Laminated ID Chart).
Online store
Visit our online store for many more butterfly related books and gifts.
Population trends 1
UK Population trend 1995-2004 down by -21%
UK Population trend 1976-2004 up by 9%

1Fox, R., Asher. J., Brereton. T., Roy, D & Warren, M. (2006) The State of Butterflies in Britain & Ireland, Pices, Oxford.
UK BAP status 2
UK BAP status not listed (link)

2For information about the UK Biodiversity Action Plan, visit the JNCC web site

National Biodiversity Network Gateway
National Biodiversity Network Gateway Distribution Map

Areas in and indicate a contraction in distribution of the Common Blue except in Ireland where data is only available up until 1999.

* Records shown in outside the natural distribution may be the result of illegal or accidental releases by breeders or, depending upon the species, migrant individuals from mainland Europe.

Key to map*
= 2000 to 2010 inclusive (current distribution)
= records from 1950 to 1999 inclusive
= records from 1900 to 1949 inclusive
Records prior to 1st January 1900 are not shown.

The NBN Gateway records are shown on the map right. (See terms and conditions).

More data is available on the Common Blue on the NBN Gateway web site.
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For full details of books and reports mentioned on this web site, view the references page.

Find out more online*
Common Blue can be found on Peter Eeles excellent UK Butterflies web site.
Common Blue can be found on Matt Rowlings excellent European Butterflies web site.

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Photographs of the Common Blue
Image ID BB2087 - Common Blue - © Steven Cheshire
Common Blue male (imago)
BB2087 ©
Image ID BB1922 - Common Blue - © Steven Cheshire
Common Blue female (imago)
BB1922 ©
Image ID BB1874 - Common Blue - © Steven Cheshire
Common Blue male (imago)
BB1874 ©
Image ID BB1873 - Common Blue - © Steven Cheshire
Common Blue male and female (imago)
BB1873 ©
Image ID BB1613 - Common Blue - © Debbie Cheshire
Common Blue female (imago)
BB1613 ©
Image ID BB1612 - Common Blue - © Debbie Cheshire
Common Blue female (imago)
BB1612 ©
Image ID BB1611 - Common Blue - © Debbie Cheshire
Common Blue male (imago)
BB1611 ©
Image ID BB1610 - Common Blue - © Debbie Cheshire
Common Blue male (imago)
BB1610 ©
Image ID BB1609 - Common Blue - © Debbie Cheshire
Common Blue male (imago)
BB1609 ©
Image ID BB1608 - Common Blue - © Steven Cheshire
Common Blue male (imago)
BB1608 ©
There are 53 photographs of the Common Blue in our stock photo library.
View more photographs of the Common Blue as a thumbnail gallery or as a slideshow.
Aberrations and forms
There are 43 named aberrant forms of the Common Blue currently listed. Find out more about aberrants here.

ab. albescens - Tutt 1910
ab. albistria - Wright 1941
ab. albocincta - Tutt 1910
ab. albocuneata - Tutt 1910
ab. albomarginata - Tutt 1910
ab. angulata - Tutt 1896
ab. anticoalbocincta - Tutt 1910
ab. anticoelunata - Verity 1943
ab. anticoelunata-supracaerulea - Verity 1943
ab. anticoelunata-thestylis - Verity 1943
ab. antico-obsoleta - Tutt 1910
ab. apicojuncta - Tutt 1910
ab. apicta-caerulescens - Tutt 1910
ab. apicta-thetis - Tutt 1910
ab. arcuata-costa-retrojuncta - Courvoisier 1912
ab. aurescens - Tutt 1910
ab. auropuncta - Bright & Leeds 1938
ab. caerulea - Fuchs 1877
ab. caeruleocincta - Tutt 1910
ab. caerulescens - Wheeler 1903
ab. cervinescens - Tutt 1910
ab. extensa - Tutt 1910
ab. flavescens - Tutt 1910
ab. fusca - Gillmer 1908
ab. glomerata - Tutt 1910
ab. hylasoides - Tutt 1910
ab. iphis-cuneata - Tutt 1896
ab. livida - Gillmer 1909
ab. melanotoxa - Pincitore-Marott 1872
ab. minor - Cockerell 1889
ab. nigromaculata - Cockerell 1889
ab. obsoleta - Gillmer 1908
ab. pallescens - Tutt 1910
ab. pallida - Tutt 1896
ab. parvipuncta - Courvoisier 1903
ab. polyphemus - Esper 1779
ab. posticoalbocincta - Tutt 1910
ab. posticocaeruleopuncta - Tutt 1910
ab. radiata - Courvoisier 1907
ab. rufina - Oberthür 1894
ab. semipersica - Tutt 1896
ab. subcaerulescens - Tutt 1910
ab. subtus-radiata - Oberthür 1896
Common Blue ab.semipersica