Butterflies of the World - Lifecycle, Ecology, Taxonomy, Conservation, Photography, Butterfly Holidays, Photo Galleries, Book Reviews and more.........
Text and photographs protected by Copyright © Adrian Hoskins 2007, and must not be published in part or in whole elsewhere without prior written permission from the author.
Butterflies of Britain & Europe
 
Northern Brown Argus
Aricia artaxerxes FABRICIUS, 1793
Family - LYCAENIDAE
subfamily - POLYOMMATINAE
 
 introduction | habitats | lifecycle | adult behaviour
 
Aricia artaxerxes, male, Sutherland. Photo courtesy Tony Mainwood © 2008
 
Introduction
 
The Northern Brown Argus, also known as the Mountain Argus or Scotch White-spot, is distributed patchily across Europe, occurring as a montane species in the Pyrenees, the Cantabrian mountains, Massif Central, the Alps, and the Balkans, but is absent from the Tatra and Carpathian ranges.
 
It also occurs at lower elevations in northern England, Scotland, and in Scandinavia.
 
Unlike it's close relative the Brown Argus Aricia agestis, it is single brooded, emerging in June and July, at which time agestis is "between broods".
 
In Britain the ranges of the 2 species do not overlap, but in Europe they often share the same habitats, and there is a degree of overlap in the flight periods. There the butterfly can also be confused with the dark females of several of the "blues", so a well illustrated field guide is essential to determine the species, which each differ in the arrangement of the spots and lunules on the underside wings.
 
The populations in northern England very closely resemble agestis on the upperside, but Scottish specimens have a prominent white spot in the discal cell of the forewings. The black spots on the undersides of northern English examples of artaxerxes are reduced in comparison with those of agestis, and absent in Scottish specimens.
 
Aricia artaxerxes, male, Sutherland. Photo courtesy Tony Mainwood © 2008
 
Habitats
 
In northern England the butterfly is found at well drained grassland habitats, usually on limestone pavements or hillsides where there are patches of scree or other small areas of bare ground.
 
In Scotland it is found in a variety of habitats including cliff tops, south-facing hillsides, open areas within woodlands, and grassy embankments. As with the English colonies, most are on limestone or granite.
 
Lifecycle
 
The butterflies emerge from mid June to early July depending on location, and lay their eggs singly on the upper-side of leaves of common rockrose ( agestis oviposits on the underside ).
 
The young caterpillar feeds in a similar manner to agestis, nibbling at the underside of the leaves, but leaving the cuticle intact, creating a distinctive pattern of tiny holes which are visible from above.
 
It hibernates from September to April, amongst withered or dead leaves at the base of the foodplant Helianthemum chamaecistus. When fully grown in May it is pale green, with a pale pinkish stripe below the spiracles. The mature caterpillar feeds openly on the upper surface of the leaves, and is attended by ants.
 
The chrysalis is formed in late May on the ground, and is also attended by ants, which cover it with soil and fragments of vegetation.
 
Adult behaviour

 

At it's habitats in northern England this species nectars at bird's foot trefoil, thyme and other low growing flowers, but in Scotland it often also attends thistles.

 

The butterflies are active only in warm sunshine, fluttering amongst grasses, and basking periodically on low herbage or patches of bare ground.

 

I have not observed courtship or copulation in this species, but it is likely to follow a similar pattern to that of agestis, in which both sexes roam freely, and copulate without any pre-nuptial ritual.

 

In dry weather the adults roost overnight on grass heads, but during wet spells they go deep into herbage, roosting on the underside of leaves.

 
                                                       
Almost every British and European species of butterfly is declining rapidly in numbers, due in most cases to loss or degradation of habitats.
 
You can help to reverse the decline by supporting conservation organisations which purchase and manage habitats as nature reserves, and which lobby government at local, national and international levels, often very successfully, to bring about changes in farming, forestry and urban development policies.
 
Please contact the conservation organisations for advice on how you can help protect British and European butterflies and their habitats. You may be able to offer practical help e.g. by monitoring butterfly populations or helping to manage nature reserves. Donations to these organisations enable them to employ ecologists and biologists. Even if you are unable to provide such help, merely having your name on the membership list can be a powerful tool for conservation organisations wishing to demonstrate the levels of support they have for their policies.

 

 
Text and photographs unless otherwise stated are protected by Copyright © Adrian Hoskins 2007-2008, and must not be reproduced or published in part or in whole elsewhere in any form without written permission from Adrian Hoskins. Breach of copyright will be pursued by litigation.
 
Photographs of Aricia artaxerxes on this page Copyright © Tony Mainwood 2008.
 
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