Wednesday, 15 February 2012
Northern Brown Argus
Scientific Name:
Aricia artaxerxes
Also Known As:
Castle Eden Argus, Scotch White-spot, the European mainland subspecies is known as the Mountain Argus
Wingspan (mm):
25-31mm Description
Similar in appearance to the Brown Argus which it replaces in Northern England and Scotland normal form has a white spot in the centre of the fore-wing although some of the English examples as in the Arnside area of Cumbria lack the white spot. Unlike the Brown Argus the Northern Brown Argus is single brooded appearing on the wing from late June until early August
Distribution
Northern England and Scotland. Isolated colonies in Durham, Northumberland, Lancashire and Cumbria more widespread in Scotland. Some of the colonies in Durham are close to Sedgefield and have good strong and vibrant populations.
Habitat
The butterfly occurs in well drained, unimproved grasslands where Common Rock-rose grows in a lightly grazed or ungrazed sward. Most sites are sheltered (often with scrub) and have thin, base-rich soils with patches of bare ground, for example coastal valleys, steep slopes, sand dunes, and quarries. In Scotland it may also occur on predominantly neutral and even acidic soils where Common Rock-rose is able to grow if there is some calcareous influence through weathering or flushing.
Diet
The most important foodplant is the Common Rock-rose, which it lays it's eggs on, though there are rare records of egg-laying (probably accidental) on other plants.
Status
UK BAP status: Priority Species Butterfly Conservation priority: high European threat status: not threatened Protected in Great Britain for sale only