Tim writes: The Northern Brown Argus occurs across northern Europe and the mountains further south but the form that occurs in Scotland occurs nowhere else. This beautiful (and little-photographed) form has a white spot on the forewing and the under side spots are white without black centres. These features are controlled by a single recessive gene, seemingly present in all Scottish butterflies and a small proportion of butterflies on the County Durham coast. Butterflies in northern England lack the white spot and have small black centres to the underside spotting. The larvae usually feed on Rock Rose.
