The argent and sable breeds in woodland with birch regrowth and in open moorland and bogs, particularly those at higher altitudes or in coastal areas. Many of the populations that survive are in the rides and edges of conifer plantations established from the 1950s onwards, where a weed growth of birch is still available though often diminishing. The larva of this species feeds on birches Betula pendula (and probably B. pubescens) and bog myrtle Myrica gale. On birch it spins two or three leaves together and feeds from within the chamber, eating just the inner surface when small and later eating right through the leaf. It feeds among the terminal leaves of bog myrtle in the same way. The moth flies by day in warm sunny weather between May to early July, with moorland populations flying later in the year. Eggs are found on birch regrowth less than 30 cm tall in full sun, and in woodland the larvae are mostly found on low birch coppice. The argent and sable overwinters as pupae, which have been found in moss at the base of trees in woodland and bog myrtle on moorland.
The argent and sable occurs throughout most of England, except East Anglia, eastern Wales, and the southern uplands, the Hebrides, and the far north-west of Scotland. It has declined throughout much of England and is now only thinly scattered. In Wales and north-west Scotland its status is less clear as the species is probably under-recorded. It is an holarctic species which is widespread in Europe (including Spain, the Alps, and north Scandinavia) and is known from Siberia, Amur, China, Korea, Japan and North America.
In Great Britain this species is classified as Nationally Scarce.
Current factors causing loss or decline
Lack of birch regeneration at wood edges and on rides in high forest systems due to the decline of coppicing and other active woodland management.
Over-grazing by sheep on moorlands, preventing birch regeneration and impacting on bog myrtle stands.
Some populations are on SSSIs.
The Forestry Commission's Coppice for Butterflies Challenge (Woodland Improvement Grant) scheme has targeted three areas where the argent and sable is present: the Wye Valley, Wessex/Hampshire Chalk, and the Morecambe Bay Limestone.
Action plan objectives and targets
Maintain existing populations.
Enhance population size at key sites by 2010.
Proposed actions with lead agencies
Policy and legislation
Where appropriate, include the requirements of the species when preparing or revising prescriptions for agri-environment and woodland grant schemes. (ACTION: CCW, NE, FC, MAFF, NAW, SE, SNH)
Site safeguard and management
Where possible, ensure that occupied habitat is appropriately managed by 2010, for example through SSSI or agri-environment/woodland grant scheme management agreements. (ACTION: CCW, NE, FC, MAFF, NAW, SE, SNH)
Where possible, increase the available habitat at known sites and in adjacent areas, and attempt to link up existing fragments of habitat. (ACTION: CCW, NE, FC, MAFF, NAW, SE, SNH)
Ensure that the species is included in site management documents for all relevant SSSI's. (ACTION: CCW, NE, SNH)
Consider notifying as SSSI's sites holding key populations of the species where this is necessary to secure their long-term protection and appropriate management. (ACTION: CCW, NE, SNH)
Species management and protection
Advise landowners and managers of the presence of this species and the importance of beneficial management for its conservation. (ACTION: CCW, NE, SNH)
As far as possible, ensure that all relevant agri-environment project officers and members of regional agri-environment consultation groups are advised of locations of this species, its importance and the management needed for its conservation. (ACTION: CCW, NE, MAFF, NAW, SE, SNH)
Future Research and Monitoring
Undertake surveys to determine the status of the species. (ACTION: CCW, NE, SNH)
Conduct targeted autecological research, including on the age of coppice after cutting preferred by the moth, the length of time such cut areas remain suitable, mobility and population structure, to inform habitat management. (ACTION: CCW, NE, SNH)
Establish a regular monitoring programme for the species. (ACTION: NE, CCW, SNH)
Assess the impact of Coppice for Butterflies Challenge on this species. (ACTION: FC)
Pass information gathered during survey and monitoring of this species to a central database for incorporation in national and international databases. (ACTION: CCW, NE, SNH)
Communications and Publicity
Promote opportunities for the appreciation of the species and the conservation issues associated with its habitat. This should be achieved via articles within appropriate journals as well as by a publicity leaflet. (ACTION: CCW, NE, SNH)
Links with other action plans
Originally published in: UK Biodiversity Group Tranche 2 Action Plans - Volume VI: Terrestrial and freshwater species and habitats (October 1999, Tranche 2, Vol VI, p99)
Visit the ARKive website to view images and further information relating to this species