Brown Argus

Aricia agestis


The Brown Argus is a small butterfly. Adults fly throughout the summer between April and October and feed on Common Rock-rose, which is also the caterpillar's foodplant, together with various species of Crane's-bills. The Brown Argus is found in dry, sunny habitats, including heathland, woodland edges, waste ground and downland, and seems to be expanding its range as the climate warms up.

How to identify

The Brown Argus is bronzy-brown above with an orange band across the edge of each wing. Very similar to the female Common Blue, but tends to be smaller, with no hint of blue.

Where to find it

Found across southern and central England and parts of the Welsh coast.


When to find it

  • April
  • May
  • June
  • July
  • August
  • September
  • October

How can people help

The Brown Argus is characteristic of chalk and limestone grasslands. Areas of rare and unique wildlife, chalk grasslands have been likened to rainforest for the diversity of species they hold. But they are being lost at an alarming rate due to changes in land use causing the decline of grazing: it's estimated that we've lost 80% of our chalk grassland over the last 60 years. The Wildlife Trusts manage many grassland nature reserves for the benefit of the rare wildlife they hold. You can help too: volunteer for your local Wildlife Trust and you could be involved in everything from scrub-cutting to stockwatching.

Species information

Common name
Brown Argus
Latin name
Aricia agestis
Butterflies and moths
Wingspan: 2.5-3cm
Conservation status