Northern Brown Argus

Aricia artaxerxes (a-RISS-ee-uh ar-ta-ZURK-seez)

Northern-Brown-Argus-artaxerxes-StAbbs 20 June 2011 03C3195
Photo © IainLeach
 

Wingspan
25 - 31mm

Checklist Number
61.016

Family:LycaenidaeLeach, 1815
Subfamily:PolyommatinaeSwainson, 1827
Tribe:PolyommatiniSwainson, 1827
Genus:AriciaReichenbach, 1817
Subgenus:  
Species:artaxerxes(Fabricius, 1793)
Subspecies:artaxerxes (Fabricius, 1793)
 salmacis (Stephens, 1828)

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Introduction

For many years, the Northern Brown Argus was considered to be a subspecies of the Brown Argus. However, it is now believed that this is a distinct species in its own right and has a different flight time and different number of broods - this species being single-brooded. Although very similar in appearance to a Brown Argus, the two can be separated by location in the British Isles, since the Northern Brown Argus is found only in the north of England and Scotland. This species exists as 2 distinct subspecies that are endemic to the British Isles, the result of being separated from its continental cousins for thousands of generations. The artaxerxes subspecies is found in Scotland and the Salmacis subspecies in northern England. Small populations may occur in Clwyd, North Wales, although these may turn out to be colonies of Brown Argus. This butterfly is not found on the Isle of Man. Most colonies are small, containing less than 50 adults.

Aricia artaxerxes ssp. artaxerxes

This species was first defined in Fabricius (1793) as shown here (type locality: England).

The nominate subspecies is characterised by the white spot found on the forewing upperside, and is found only in Scotland.

Northern Brown Argus male - St Abb's Head 20-June-2013

Male
Photo © Neil Hulme

Northern Brown Argus male - St Abb's Head 20-June-2013

Male Underside
Photo © Neil Hulme

Northern Brown Argus - female - Burnmouth - 09-Jul-13-15

Female
Photo © Pete Eeles

Northern Brown Argus - female - St. Abbs Head - 09-Jul-13

Female Underside
Photo © Pete Eeles

Photo Album ...


Aricia artaxerxes ssp. salmacis

This subspecies was first defined in Stephens (1828b) as shown here (type locality: Castle Eden Dene, County Durham, England).

This subspecies represents the population found in northern England, in a band that runs between Westmorland and Mid-west Yorkshire in the west to Durham in the east. When compared with the subspecies artaxerxes, this subspecies has greatly reduced, sometimes absent, white spots on the forewings. This subspecies is also known as the Castle Eden Argus.

Aricia artaxerxes ssp. salmacis (Stephens, 1828)

Original (English and Latin)

From whom [G.Wailes, Esq.] I have also recently obtained specimens of what seems to be a new species of Polyommatus, intermediate between Po. Agestis and Artaxerxes, and which I propose calling Po. Salmacis, thus briefly characterised:-

Po. Salmacis. Alis fusco-nigris, subtus fuscescentibus maculis subocellatis, anticis supra in masculis puncto discoidali atro, in faeminis albo, posticis utrinque fascia submarginali rubra. (Exp. alar. [Male] 1 unc. 1 lin.; [Female] 1 unc. 2 lin.)

"Taken on Castle Eden Dean." - G.Wailes, Esq.

Translation

From whom [G.Wailes, Esq.] I have also recently obtained specimens of what seems to be a new species of Polyommatus, intermediate between Po. Agestis and Artaxerxes, and which I propose calling Po. Salmacis, thus briefly characterised:-

Po. Salmacis. Wings brownish black, with darkish eye-like spots beneath, with a black discoidal spot in the male on the forewing upperside, white in the female, the hindwing on both sides having a red submarginal band. (Wingspan ♂ 1 inch 1 line; ♀ 1 inch 2 lines)

"Taken on Castle Eden Dean." - G.Wailes, Esq.

Northern-Brown-Argus-salmacis-Latterbarrow 11 June 2011 03C6584

Male
Photo © IainLeach

Northern Brown Argus - imago - Arnside Knott - 12-Jul-05 (2)

Male Underside
Photo © Pete Eeles

Northern Brown Argus Female - Arnside Knott, Cumbria 9-July-09

Female
Photo © Vince Massimo

Northern Brown Argus - female - Bishop Middleham Quarry, County Durham - 12-Jul-13-5

Female Underside
Photo © Pete Eeles

Photo Album ...


History

The table below shows a chronology of vernacular names attributed to this species. Any qualification of the name (e.g. male, female) is shown in brackets after the name.

YearNameReference
1795Brown WhitespotLewin (1795)
1803Scotch ArgusHaworth (1803)
1813ArtaxerxesDonovan (1813)
1819White-spot BrownSamouelle (1819)
1853Brown Argus BlueMorris (1853)
1871Scotch Brown ArgusNewman (1871)
1906Scotch White SpotSouth (1906)
1959Scotch Brown BlueHeslop (1959)
1973Northern Brown ArgusHowarth (1973)

Conservation Status

Population levels of this butterfly have shown an ongoing decline, primarily caused by inappropriate grazing and, in Scotland, loss of suitable habitat to tree plantations. This butterfly is therefore a priority species for conservation efforts.

UK BAP StatusOccurrence Change
1976-2014 (%)
Abundance Change
1976-2014 (%)
Occurrence Change
2005-2014 (%)
Abundance Change
2005-2014 (%)
Priority Species
Click here to access the Biodiversity Action Plan (BAP) for this species.
Decrease-27
Large Decrease-52
Decrease-36
Stable+6

The table above shows the occurrence (distribution) and abundance (population) trends, using information from The State of the UK's Butterflies 2015 (Fox, 2015). Any UK BAP status is taken from the UK Biodiversity Action Plan (UK BAP) (2007 review).

Habitat

This species is found on sheltered south-facing slopes, or in hollows. Alkaline ground, such as limestone, is preferred since this favours the growth of the larval foodplant, Common Rock-rose. This butterfly can be found on limestone grassland, coastal valleys and quarries, limestone pavement and outcrops.

Distribution

 

Click here to see the distribution of this species or here to see the distribution of this species together with specific site information overlaid.

Life Cycle

This species has a single brood. Adults emerge in early June, peaking at the end of June, except in north-east Scotland, where adults emerge toward the end of June, peaking in the middle of July.

Aricia artaxerxes ssp. artaxerxes

Aricia artaxerxes ssp. salmacis

The chart(s) above have been correlated with the phenology plot below, taken from the UK Butterfly Monitoring Scheme. The blue line gives average counts over the full data set from 1976 to date, and the red line gives the average for the last year.

Imago

This is a warmth-loving species, with both male and female flying in warm sunshine. Both sexes roost head-down on a grass stem and, like the Brown Argus and Common Blue, roost communally.

Adults feed primarily on Thyme (Thymus polytrichus).

Aricia artaxerxes ssp. artaxerxes

Northern Brown Argus - female - St. Abbs Head - 09-Jul-13-7

Photo © Pete Eeles
09-Jul-2013

Northern Brown Argus - female - Burnmouth - 30-Jun-14

Photo © Pete Eeles
30-Jun-2014

Northern Brown Argus - female - St. Abbs Head - 09-Jul-13-10

Photo © Pete Eeles
09-Jul-2013

Northern Brown Argus - imago - Port O Warren - Unknown date [Adrian Riley]

Photo © Adrian Riley

Northern-Brown-Argus-artaxerxes-StAbbs 20 June 2011 03C3561

Photo © IainLeach

Northern-Brown-Argus-artaxerxes-StAbbs 20 June 2011 03C4736

Photo © IainLeach

Northern Brown Argus - female - Burnmouth - 09-Jul-13-11

Photo © Pete Eeles
09-Jul-2013

Northern Brown Argus - male - Burnmouth - 09-Jul-13-16-2

Photo © Pete Eeles
09-Jul-2013

Northern-Brown-Argus-artaxerxes-StAbbs 20 June 2011 03C3195

Photo © IainLeach

Northern Brown Argus - male - Burnmouth - 09-Jul-13

Photo © Pete Eeles
09-Jul-2013

Northern Brown Argus - female - St. Abbs Head - 09-Jul-13-6

Photo © Pete Eeles
09-Jul-2013

Northern Brown Argus - female - Burnmouth - 09-Jul-13-15-2

Photo © Pete Eeles
09-Jul-2013

Northern Brown Argus - male - Burnmouth - 09-Jul-13-14

Photo © Pete Eeles
09-Jul-2013

Northern Brown Argus - male - Burnmouth - 09-Jul-13-12

Photo © Pete Eeles
09-Jul-2013

Northern Brown Argus, East Lothian, 8-July 2013

Photo © NickMorgan
08-Jul-2013

Northern Brown Argus - male - Burnmouth - 09-Jul-13-13

Photo © Pete Eeles
09-Jul-2013

Northern Brown Argus male - St Abb's Head 20-June-2013

Photo © Neil Hulme
20-Jun-2013

Northern-Brown-Argus-artaxerxes-StAbbs 20 June 2011 03C5242

Photo © IainLeach

Northern Brown Argus, East Lothian, 10-July 2013

Photo © NickMorgan
10-Jul-2013

Northern Brown Argus - female - Burnmouth - 09-Jul-13-15

Photo © Pete Eeles
09-Jul-2013

Photo Album (42 photos) ...


Aricia artaxerxes ssp. salmacis

Northern-Brown-Argus-salmacis-Latterbarrow 11 June 2011 03C6584

Photo © IainLeach

Northern Brown Argus - female - Bishop Middleham Quarry, County Durham - 12-Jul-13-6

Photo © Pete Eeles
12-Jul-2013

Northern Brown Argus - imago - Latterbarrow - 02-Jul-05 [Derek Brown]

Photo © Derek Brown

Northern Brown Argus - female - Bishop Middleham Quarry, County Durham - 12-Jul-13

Photo © Pete Eeles
12-Jul-2013

Northern Brown Argus - Gait Barrows 29.07.2015

Photo © Neil Freeman
29-Jul-2015

Northern Brown Argus Male Underwings - Bishop Middleham Quarry, Co Durham - 23rd June 2012

Photo © Graham Beckwith
23-Jun-2012

Northern Brown Argus ssp salmacis - Latterbarrow 12.06.2014

Photo © Neil Freeman
12-Jun-2014

Northern Brown Argus (mating) (ssp.salmacis) 5.7.12 Latterbarrow, Cumbria. Downland boy

Photo © downland boy

Northern Brown Argus - imago - Arnside Knott - 12-Jul-05 (3)

Photo © Pete Eeles
13-Jul-2005

Northern Brown Argus - female - Bishop Middleham Quarry, County Durham - 12-Jul-13-5

Photo © Pete Eeles
12-Jul-2013

Northern-Brown-Argus-salmacis-Latterbarrow 11 June 2011 03C6567

Photo © IainLeach

Northern Brown Argus - imago - Whitbarrow Scar - 06-Jun-04 [Allan Sumner]

Photo © Allan Sumner

Northern Brown Argus Male - Arnside Knott, Cumbria 9-July-07

Photo © Vince Massimo
09-Jul-2007

Northern-Brown-Argus-salmacis-Latterbarrow 11 June 2011 03C6484

Photo © IainLeach

Northern Brown Argus Male - Arnside Knott  24-June-2011

Photo © Keith Woonton
Note the almost complete absents of any orange on the forewings. This specimen is at the edge of the normal range of colour variation for this Subspecies: salmacis.

Northern Brown Argus - imago - Arnside Knott - 29-Jun-06 (0418)

Photo © Pete Eeles
29-Jun-2006

Northern-Brown-Argus-salmacis-Latterbarrow 11 June 2011 03C5760

Photo © IainLeach

Northern Brown Argus ssp salmacis - Latterbarrow 12.06.2014

Photo © Neil Freeman
12-Jun-2014

Northern Brown Argus (1) [Nick Sampford]

Photo © Nick Sampford

Northern Brown Argus ssp salmacis - Latterbarrow 12.06.2014

Photo © Neil Freeman
12-Jun-2014

Photo Album (32 photos) ...


Ovum

Eggs are laid singly on the upperside of leaves of the foodplant, unlike those of the Brown Argus which are generally laid on the underside of leaves.

Northern Brown Argus egg (hatched) - Scottish Borders 18-Aug-2012

Photo © NickMorgan

Northern Brown Argus egg  - Scottish Borders 18-Aug-2012

Photo © NickMorgan

Northern Brown Argus, ovum, Selkirk, Scottish Borders 02/07/2011

Photo © NickMorgan

NBA Ovum, Berwickshire coast, 13th July 2012. Blaikie Heugh (south of Eyemouth).

Photo © IAC
On Rockrose
13-Jul-2012

Northern Brown Argus - ovum - Bishop Middleham Quarry, County Durham - 12-Jul-13

Photo © Pete Eeles
13-Jul-2013

Northern Brown Argus - ovum - Bishop Middleham Quarry, County Durham - 12-Jul-13-2

Photo © Pete Eeles
13-Jul-2013

Northern Brown Argus - ovum - St. Abbs Head - 09-Jul-13

Photo © Pete Eeles
09-Jul-2013

Northern Brown Argus - ovum - St. Abbs Head - 09-Jul-13-2

Photo © Pete Eeles
09-Jul-2013

Northern Brown Argus - ovum - St. Abbs Head - 09-Jul-13-2-2

Photo © Pete Eeles
09-Jul-2013

Northern Brown Argus - ovum - St. Abbs Head  - 30-Jun-14-6

Photo © Pete Eeles
30-Jun-2014

Northern Brown Argus - ovum - St. Abbs Head  - 30-Jun-14-7

Photo © Pete Eeles
30-Jun-2014

Northern Brown Argus - ovum - St. Abbs Head  - 30-Jun-14-8

Photo © Pete Eeles
30-Jun-2014

Northern Brown Argus - ovum - St. Abbs Head  - 30-Jun-14-9

Photo © Pete Eeles
30-Jun-2014

Northern Brown Argus - ovum - St. Abbs Head  - 30-Jun-14-10

Photo © Pete Eeles
30-Jun-2014

Northern Brown Argus - ovum - St. Abbs Head  - 30-Jun-14

Photo © Pete Eeles
30-Jun-2014

Northern Brown Argus - Bishop Middleham Quarry - 2 July 2011.

Photo © Tony Moore
02-Jul-2011

Northern Brown Argus - ovum - Arnside Knott - 30-Jul-14-2

Photo © Pete Eeles
30-Jul-2014

Northern Brown Argus - ovum - Arnside Knott - 30-Jul-14

Photo © Pete Eeles
30-Jul-2014

Photo Album (18 photos) ...


Larva

The larva hibernates in the 3rd instar and there are 5 moults in total. It is occasionally tended by ants.

The primary larval foodplant is Common Rock-rose (Helianthemum nummularium).

Northern Brown Argus - larva - Perthshire - Unknown date (3) [REARED] [Graham Smith]

Photo © Graham Smith

Northern Brown Argus - larva - Perthshire - Unknown date (4) [REARED] [Graham Smith]

Photo © Graham Smith

Northern Brown Argus - larva - Perthshire - Unknown date (5) [REARED] [Graham Smith]

Photo © Graham Smith

Northern Brown Argus - larva - Burnmouth - 09-Jul-14

Photo © Pete Eeles
09-Jul-2014

Northern Brown Argus - larva - Burnmouth - 10-Apr-15

Photo © Pete Eeles
10-Apr-2015

Northern Brown Argus - larva - Burnmouth - 11-Apr-15

Photo © Pete Eeles
11-Apr-2015

Northern Brown Argus - larva - Burnmouth - 12-Jul-14

Photo © Pete Eeles
12-Jul-2014

Northern Brown Argus - larva - Burnmouth - 16-Apr-15

Photo © Pete Eeles
16-Apr-2015

Northern Brown Argus - larva - Burnmouth - 27-Aug-14

Photo © Pete Eeles
27-Aug-2014

Photo Album (9 photos) ...


1st Instar

Description to be completed.

Northern Brown Argus - larva (1st instar) - Burnmouth - 05-Jul-14

Photo © Pete Eeles
05-Jul-2014

Photo Album (1 photos) ...


2nd Instar

Description to be completed.

3rd Instar

Description to be completed.

4th Instar

Description to be completed.

5th Instar

Description to be completed.

Aricia artaxerxes - Larva with little red, e.o. Nockalmberge) [Wolfgang Wagner]

Photo © Wolfgang Wagner
www.pyrgus.de

Photo Album (1 photos) ...


Pupa

The pupa is formed in loose vegetation that is held together with a few silk threads. Like the larva, the pupa is also tended by ants.

Northern Brown Argus - pupa - Perthshire - 02-Apr-05 [REARED] [Graham Smith]

Photo © Graham Smith

Aricia artaxerxes - Pupa (e.o. Nockalmberge 2009) [Wolfgang Wagner]

Photo © Wolfgang Wagner
www.pyrgus.de

Photo Album (2 photos) ...


Aberrations

Description to be completed.

Click here to see the aberration descriptions and images for this species.

Similar Species

Adonis Blue

Description to be completed.

Brown Argus

Although very similar in appearance, the Brown Argus and Northern Brown Argus can be separated by location in the British Isles. However, this situation may change with global warming as the Brown Argus moves further north.


Brown Argus and Northern Brown Argus distributions

Chalk Hill Blue

Description to be completed.

Common Blue

Of the two sexes, it is the female Common Blue that causes most confusion with the Northern Brown Argus. The blue present in a female Common Blue is highly variable, with individuals ranging from almost completely blue through to completely brown. It is this latter colouring that causes the most confusion. Even so, the Northern Brown Argus has no blue scales, but may give off a blue sheen from the wings and the hairs found on the thorax and abdomen. Another diagnostic is that the Northern Brown Argus normally has a prominent dark spot in the centre of the forewings and, in the case of the artaxercxes subspecies of Northern Brown Argus, it a distinctive white dot. Any identification challenges are usually, therefore, with respect to the salmacis subspecies of Northern Brown Argus that does not have this white spot.


Common Blue female (left) and Northern Brown Argus ssp. salmacis (right)

Differentiating Common Blue and Northern Brown Argus from their undersides is even more problematic, and we need to resort to the pattern of spots. Here we have two distinguishing features. The first is that the Common Blue has a spot on the underside of the forewing that is absent in the Northern Brown Argus. The second is that two of the spots on the leading edge of the hindwing are relatively-close in the Northern Brown Argus, almost forming a "figure of eight", but are more spaced apart in the Common Blue. This diagnostic is particularly useful if the underside of the forewing isn't visible.


Common Blue (left) and Northern Brown Argus (right)

Videos


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The following links provide additional information on this butterfly.

References

The species description provided here references the following publications:

ReferenceDetails
Donovan (1813) Donovan, E. (1813) The Natural History of British Insects (Vol.16).
Fabricius (1793) Fabricius, J.C. (1793) Entomologia systematica emendata et aucta, secundum classes, ordines, genera, species.
Haworth (1803) Haworth, A.H. (1803) Lepidoptera Britannica.
Heslop (1959) Hislop, I.R.P. (1959) A new label list of British macrolepidoptera. Entomologist's Gazette.
Howarth (1973) Howarth, T.G. (1973) South's British Butterflies.
Leach (1815) Leach (1815) In Brewster: The Edinburgh Encyclopaedia.
Lewin (1795) Lewin, W. (1795) The Papilios of Great Britain.
Morris (1853) Morris, Rev.F.O. (1853) A History of British Butterflies.
Newman (1871) Newman, E. (1871) An Illustrated Natural History of British Butterflies.
Reichenbach (1817) Reichenbach, R.L. (1817) Jenaische Allgemeine Literatur-Zeitung.
Samouelle (1819) Samouelle, G. (1819) The Entomologist's Useful Compendium.
South (1906) South, R. (1906) The Butterflies Of The British Isles.
Stephens (1828b) Stephens, J.E. (1828) Illustrations of British Entomology (Haustellata Vol.3).
Swainson (1827) Swainson, W. (1827) A Sketch of the Natural Affinities of the Lepidoptera Diurna of Latreille. The Philosophical magazine : or Annals of chemistry, mathematics, astronomy, natural history and general science.