Steven Cheshire's British Butterflies
British Butterflies: Species: Species Account - The Brown Argus:
Brown Argus
Aricia agestis (Denis & Schiffermüller, 1775)

Brown Argus egg.
ova
  Brown Argus caterpillar.
larva
  Brown Argus chrysalis
pupa
Brown Argus
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Nomenclature
Insecta: Lepidoptera : Family Lycaenidae: Subfamily Lycaeninae : Genus Aricia: Species agestis:
Description
One of the most difficult butterflies to distinguish from the Common Blue the Brown Argus lacks the two extra spots on the underside of the forewing which are present on the Common Blue. As they fly low to the ground they have a silvery appearance frequently stopping to perch or feed on flowers.

The Brown Argus has chocolate brown wings with orange spots near the edge and fringed with white. There is a black spot in the centre of the upper wing. The undersides of the wings are grey/brown with white ringed black spots and orange markings.

The males and females are similar although the sexes can be distinguished by the orange spots. These spots clearly extend to the leading edge of the forewing in the females, while in the males, the spots fade, are very pale or absent at this point. 

Brown Argus butterflies will often roost communally in sheltered areas although it is rarely seen in large numbers... usually only one or two individuals are encountered at any one site.

The larvae are green with a red/pink strip down each side. There is a close relationship with ants.

The Brown Argus is a close relative of the
Northern Brown Argus which is restricted to Scotland and northern England.
Habitat
The Brown Argus is commonly found on chalk and limestone grassland but it also occurs in small numbers on a range of other habitats including sand dunes woodland clearings heath land disused railway lines, road verges, and set-aside fields.
Distribution
The Brown Argus occurs throughout Southern England Norfolk the South coast of Wales through the midlands into Lincolnshire. It is however absent from Cornwall Devon and parts of Dorset.
Where to see the Brown Argus in the British Isles
Cambridgeshire: Fleam Dyke and Devil's Dyke
Dorset: Fontmell Down
Other notes

Lifecycle chart
larvaelarvaelarvaelarvaepupapupaadultovalarvaeadultlarvaepupaadultovalarvaepupaadultovalarvaeadultlarvaelarvaelarvae
 
Flight chart
JanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember
The lifecycle and flight charts should be regarded as approximate guides to the Brown Argus 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.
Wingspan
25-31mm
UK status
Resident
Larval foodplants
On calcareous grassland Common Rock-rose (Helianthemum nummularium) is the primary larval food plant.

In other habitats it uses Dove's-foot Crane's-bill (Geranium molle) and Common Stork's-bill (Erodium cicutarium).

It is also possible that the Brown Argus feeds on Cut-leaved Crane's-bill (Geranium dissectum) Meadow Crane's-bill (Geranium pratense) and Hedgerow Crane's-bill (Geranium pyrenaicum).
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 -61%
UK Population trend 1976-2004 up by 16%

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 jncc.defra.gov.uk.

National Biodiversity Network Gateway
National Biodiversity Network Gateway Distribution Map



Areas in and indicate a contraction in distribution of the Brown Argus 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 Brown Argus 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*
Brown Argus can be found on Peter Eeles excellent UK Butterflies web site.
Brown Argus can be found on Matt Rowlings excellent European Butterflies web site.

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Photographs of the Brown Argus
Image ID BB2369 - Brown Argus - © Steven Cheshire
Brown Argus female (imago)
BB2369 ©
Image ID BB2368 - Brown Argus - © Steven Cheshire
Brown Argus female (imago)
BB2368 ©
Image ID BB2367 - Brown Argus - © Steven Cheshire
Brown Argus female (imago)
BB2367 ©
Image ID BB2322 - Brown Argus - © Steven Cheshire
Brown Argus female (imago)
BB2322 ©
Image ID BB2321 - Brown Argus - © Steven Cheshire
Brown Argus female (imago)
BB2321 ©
Image ID BB2220 - Brown Argus - © Steven Cheshire
Brown Argus male (imago)
BB2220 ©
Image ID BB2106 - Brown Argus - © Steven Cheshire
Brown Argus (imago)
BB2106 ©
Image ID BB2086 - Brown Argus - © Steven Cheshire
Brown Argus male and female (imago)
BB2086 ©
Image ID BB2085 - Brown Argus - © Steven Cheshire
Brown Argus male and female (imago)
BB2085 ©
Image ID BB2084 - Brown Argus - © Steven Cheshire
Brown Argus male and female (imago)
BB2084 ©
There are 59 photographs of the Brown Argus in our stock photo library.
View more photographs of the Brown Argus as a thumbnail gallery or as a slideshow.
Aberrations and forms
There are 16 named aberrant forms of the Brown Argus currently listed. Find out more about aberrants here.

ab. albicans - Aurivillius 1888
ab. albisignata - Tutt 1912
ab. albolimbata - Lempke 1955
ab. deleta - Cockerell 1889
ab. discreta - Tutt 1912
ab. elongata - Courvoisier 1910
ab. impunctata - Oberthür 1910
ab. lilliputana - Oberthür 1916
ab. nigropunctata - Tutt 1912
ab. obsoleta - Tutt 1912
ab. pallidior - Oberthür 1910
ab. retrojuncta - Lempke 1955
ab. semi-allous - Harrison 1906
ab. snelleni - ter Haar 1900
ab. subtus-radiata - Oberthür 1896
ab. unicolor - Lempke 1955