Aricia artaxerxes northern brown argus
Current status: WCA5 (with respect to sale only); Nationally scarce
The northern brown argus occurs on well drained soils, usually on limestone, where its larva feed on common rock-roseHelianthemum nummularium. It occurs throughout northern England and Scotland, including populations in east Durham.
The northern brown argus is represented in Britain by two sub-species. One ofthese, the Durham argusA. Artaxerxes ssp. salmacis, is found only in County Durham and may be endemic.
Undergrazing leading to scrubbing over of sites and loss of habitat; overgrazing leading to loss of larval foodplants; increasing isolation of populations leading to increased risk of local extinctions, bracken encroachment.