Scotch Argus

The Scotch Argus (Erebia aethiops) is a distinctive butterfly known for its dark, velvety appearance and its preference for cool, damp Scottish habitats. It is one of the last butterflies to emerge in the summer, with its peak activity often occurring in August.

Here are some interesting facts about the Scotch Argus:

• "Sun-worshipper" Behaviour: Although they can tolerate cool weather, these butterflies primarily fly in sunshine. On sunny days, males are incredibly restless, constantly weaving low through grass looking for mates, but will immediately hide in the vegetation if a cloud covers the sun.

• Extreme Local Distribution: While common in Scotland, this butterfly is extremely rare in England. It is restricted to only two known sites in Cumbria: Arnside Knott and Smardale Gill.

• Unique Caterpillar Feeding Habits: Before winter, the caterpillars feed on grass during both day and night. However, when they emerge in the spring, they only feed at night.

• They "Play Dead": When disturbed, the caterpillars, which are pale brownish-green with short bristles, will fall from the grass stems and appear to be dead, likely as a defense mechanism.

• They Live Nearly a Year: The larvae (caterpillars) live for about ten months, while the adult butterfly only lives for a few weeks.

• Appearance: They are dark brown, nearly black, with orange patches on the wings that hold several white-centred black spots (eyespots). Females are generally lighter in color and have larger, more pronounced orange patches.

• Hibernation: They spend the winter hibernating as caterpillars in the leaf litter at the base of grass plants.

• Host Plants: In Scotland, the larvae feed primarily on Purple Moor-grass, whereas the English colonies in Cumbria feed on Blue Moor-grass.

• Not a "True" Highland Species: Despite its name, it is generally found in lower-lying, sheltered habitats like riverbanks, woodland edges, and marshy grassland, rather than high mountain tops.