Northern brown argus butterflies occur in small colonies of less than fifty individuals and the females have only one brood a year. Northern brown argus’ are dark brown in colour with several orange crescents towards the edges of the wings. These crescents are small or absent on the forewings, which have a white spot in the centre of the upperside and have pale undersides.

Behaviour

The Northern brown argus’ preferred habitat is often where common rock-rose, the larval food source of choice, is found growing. This encourages the Northern brown argus to select alkaline ground, such as limestone, as habitat and can be found on south facing slopes and in hollows. Individuals roost communally and enjoy flying in warm sunshine.

Size

Wingspan: 2-2.5cm

Status

Listed as Vulnerable on the 2010 IUCN Red List and is a UKBAP priority species.

Distribution

Found across Scotland.

When to see

June – August

Facts

• For many years, this butterfly was thought to be a subspecies of brown argus. It is has since been discovered to be a separate species and has been shown to have a different flight time and different number of broods.