Steven Cheshire's British Butterflies
British Butterflies: Species: Species Account - The Chalkhill Blue:
Chalkhill Blue
Polyommatus coridon (Poda, 1761)

Chalkhill Blue egg.
ova
  Chalkhill Blue caterpillar.
larva
  Chalkhill Blue chrysalis
pupa
Chalkhill Blue
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Nomenclature
Insecta: Lepidoptera : Family Lycaenidae: Subfamily Lycaeninae : Genus Polyommatus: Species coridon:
Description
The male Chalkhill Blue is a pale shiny sky-blue colour. Its wing edges have a dark brown band... the rear wings with small spots and brown edge band fringed with white. It is one of the largest blue butterflies in the UK. The males fly just above the vegetation searching for females. Large numbers of males may congregate on animal dung and moist soil where they feed on minerals.

The female is much less conspicuous being a dark chocolate brown colour and more secretive in behaviour, spending less time than the males in flight
.
Habitat
The Chalkhill Blue is found on short calcareous grassland in Southern England where the larval food plant Horseshoe Vetch together with a population of ants. The ants protect the pupae in their nests in return for sugars and proteins which the caterpillars and pupae produce.
Distribution
Where to see the Chalkhill Blue in the British Isles
Cambridgeshire: Devils Dyke
Bedfordshire: Totterhoe Quarry
Hertfordshire: Therfield Heath
Gloucestershire: Prestbury Hill
Dorset: Corfe Castle, Fontmell Down, Ballard Down, Cerne Abbas Giant, Badbury Rings
Isle of Wight: Bonchurch Down, Compton Down
Wessex: Martin Down, Old Winchester Hill
Other notes
Lifecycle chart
ovaovaovalarvaelarvaelarvaepupapupaadultadultovaadultovaovaovaova
 
Flight chart
JanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember
The lifecycle and flight charts should be regarded as approximate guides to the Chalkhill 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.
Near Threatened Near Threatened

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

4More information about IUCN categories.
Wingspan
33-40mm
UK status
Resident
Larval foodplants
Horseshoe Vetch (Hippocrepis comosa)
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 -34%
UK Population trend 1976-2004 up by 31%

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 species of conservation concern (link)

2For information about the UK Biodiversity Action Plan, visit the JNCC web site jncc.defra.gov.uk.

National Biodiversity Network Gateway
National Biodiversity Network Gateway Distribution Map



Areas in and indicate a contraction in distribution of the Chalkhill 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 Chalkhill Blue on the NBN Gateway web site.
Powered by NBN Gateway.
References
For full details of books and reports mentioned on this web site, view the references page.

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

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Photographs of the Chalkhill Blue
Image ID BB2335 - Chalkhill Blue - © Steven Cheshire
Chalkhill Blue male (imago)
BB2335 ©
Image ID BB2334 - Chalkhill Blue - © Steven Cheshire
Chalkhill Blue female (imago)
BB2334 ©
Image ID BB2333 - Chalkhill Blue - © Steven Cheshire
Chalkhill Blue female (imago)
BB2333 ©
Image ID BB2332 - Chalkhill Blue - © Steven Cheshire
Chalkhill Blue female (imago)
BB2332 ©
Image ID BB2331 - Chalkhill Blue - © Steven Cheshire
Chalkhill Blue male (imago)
BB2331 ©
Image ID BB2330 - Chalkhill Blue - © Steven Cheshire
Chalkhill Blue male (imago)
BB2330 ©
Image ID BB2329 - Chalkhill Blue - © Steven Cheshire
Chalkhill Blue male (imago)
BB2329 ©
Image ID BB2328 - Chalkhill Blue - © Steven Cheshire
Chalkhill Blue female (imago)
BB2328 ©
Image ID BB2327 - Chalkhill Blue - © Steven Cheshire
Chalkhill Blue female (imago)
BB2327 ©
Image ID BB2326 - Chalkhill Blue - © Steven Cheshire
Chalkhill Blue female (imago)
BB2326 ©
There are 49 photographs of the Chalkhill Blue in our stock photo library.
View more photographs of the Chalkhill Blue as a thumbnail gallery or as a slideshow.
Aberrations and forms
There are 87 named aberrant forms of the Chalkhill Blue currently listed. Find out more about aberrants here.

ab. addenda - Tutt 1909
ab. alba - Bright & Leeds 1938
ab. albescens - Bright & Leeds 1938
ab. albocuneata - Bright & Leeds 1938
ab. albomaculae - Bright & Leeds 1938
ab. alternafimbriata - Bright & Leeds 1938
ab. anticaeca - Bright & Leeds 1938
ab. anticrassilunulata - Bright & Leeds 1938
ab. antidecrescens - Bright & Leeds 1938
ab. antidiscoelongata - Bright & Leeds 1938
ab. antidiscoradiata - Bright & Leeds 1938
ab. antiextrema - Bright & Leeds 1938
ab. antiglomerata - Bright & Leeds 1938
ab. antiobsoleta - Bright & Leeds 1938
ab. antiobsoletissima - Bright & Leeds 1938
ab. antipluripuncta - Bright & Leeds 1938
ab. antiradiata - Bright & Leeds 1938
ab. antisagittata - Bright & Leeds 1938
ab. atrescens - Tutt 1910
ab. aurea - Bright & Leeds 1938
ab. aurotithonus - Tutt 1910
ab. caerumaculae - Bright & Leeds 1938
ab. castanea - Tutt 1910
ab. chlorescens - Tutt 1910
ab. cinnameus - Bright & Leeds 1938
ab. corydonis - Bergstrasser 1779
ab. crassipuncta - Tutt 1910
ab. discoidalisnulla - Bright & Leeds 1938
ab. extrema - Bright & Leeds 1938
ab. fowleri - South 1900
ab. fumidescens - Bright & Leeds 1938
ab. glabrata - Bright & Leeds 1938
ab. grisea - Tutt 1910
ab. impar - Cockayne 1916
ab. inaequalis - Tutt 1896
ab. increscens - Bright & Leeds 1938
ab. i-nigrum - Tutt 1910
ab. irregularia - Bright & Leeds 1938
ab. khaki - Bright & Leeds 1938
ab. livida - Bright & Leeds 1938
ab. lucretia - Gaschet 1877
ab. lunulata - Tutt 1909
ab. melaina - Tutt 1910
ab. metallica - Bright & Leeds 1938
ab. minutissimus - Tutt 1910
ab. mixtaalbocincta - Bright & Leeds 1938
ab. nigrescens - Bright & Leeds 1938
ab. obsolescens - Tutt 1910
ab. obsoleta - Bright & Leeds 1938
ab. ochracea - Frohawk 1938
ab. ochrea - Bright & Leeds 1938
ab. opposita - Tutt 1909
ab. ornamenta - Bright & Leeds 1938
ab. pallida - Tutt 1910
ab. pallidula - Bright & Leeds 1938
ab. parallela - Courvoisier 1907
ab. parvipuncta - Courvoisier 1907
ab. polonus - Zeller 1845
ab. postaurantiaextensa - Bright & Leeds 1938
ab. postcaeca - Bright & Leeds 1938
ab. postdiscoelongata - Bright & Leeds 1938
ab. postobsoleta - Bright & Leeds 1938
ab. postobsoletissima - Bright & Leeds 1938
ab. postradiata - Bright & Leeds 1938
ab. postradiosa - Bright & Leeds 1938
ab. postsagittata - Bright & Leeds 1938
ab. pulla - Bright & Leeds 1938
ab. punctata - Tutt 1896
ab. radiata - Bright & Leeds 1938
ab. radio - Bright & Leeds 1938
ab. semialbescens - Bright & Leeds 1938
ab. semibi-i-nigrum - Bright & Leeds 1938
ab. semilimbojuncta - Bright & Leeds 1938
ab. seminigra - Preissecker 1906
ab. semisyngrapha - Tutt 1896
ab. suffescens - Bright & Leeds 1938
ab. suffusa - Tutt 1896
ab. supraalbocrenata - Bright & Leeds 1938
ab. supramelaina - Bright & Leeds 1938
ab. syngrapha-inframarginata - Bright & Leeds 1938
ab. transformis - Bright & Leeds 1938
ab. ultracaerucrenata - Bright & Leeds 1938
ab. ultrafowleri-margino - Bright & Leeds 1938
ab. ultrainaequalis - Bright & Leeds 1938
ab. ultramelaina - Bright & Leeds 1938
ab. ultranubila - Bright & Leeds 1938
ab. ultraviridescens - Bright & Leeds 1938