Northern Brown Argus

This small butterfly has a silvery appearance as it flies low to the ground over sheltered flowery grasslands. In Britain and mainland Europe, the pattern of wing spots is highly variable and many local races (and sub-species) have been described. 

In Scotland, most individuals are of the race artaxerxes and have a characteristic white spot in the middle of the forewing (see photo). In northern England, this spot is generally dark brown or black. Similar to Brown Argus but differentiated by orange spots. The butterfly occurs mainly as small, scattered colonies and has declined in northern England.

Size and Family

• Family: Blues
• Size: Small
• Wing Span Range (male to female): 29mm

Conservation Status

• Section 41 species of principal importance under the NERC act in England
• Scottish Biodiversity List
• UK BAP status: Priority Species                   
• Butterfly Conservation: High                     
• European status: Not threatened             
• Protected under Schedule 5 of the 1981 Wildlife and Countryside Act (for sale only)

Caterpillar Foodplants

The most important food plant is Common Rock-rose (Helianthemum nummularium), though there are rare records of egg laying (probably accidental) on other plants.

Lifecycle

Habitat

Occurs usually in well drained, lightly grazed or ungrazed unimproved grasslands. They prefer sheltered habitats, frequently with scrub and patches of bare ground such as; sand dunes, quarries, coastal valleys and steep slopes.

Distribution

• Countries: England, and Scotland.
• Distribution Trend Since 1970’s = -27%.