Silver-studded Blues are on the cusp of emerging. Look for the bright blue males flitting among the heather and grasses.
Photo: © Natural England/Allan Drewitt
Scientific name: Plebejus argus
Cornish name: ‘Tikki-dui’ is the general word for butterfly
Status: GB Red List: Vulnerable
What to look for:
- Colouring: Males have vibrantly blue, dark-bordered uppersides to their wings, while the females are brown with orange spots along the edge.
- Size: Wingspan: 26 to 32 mm.
- Where: Mainly on heathland, sand dunes and limestone in Southern England, with a small number of colonies in Wales and Eastern England.
- When: Mainly mid-June through to August.
- Similar species: Common Blue [https://23.naturallizard.co.uk/2014/08/06/common-blue-butterfly/]; females may be confused with the Brown Argus.
If you have the chance to take a close look at the underside of this lovely small butterfly’s wings, you’ll soon spot how it got its name. There is usually a silvery, reflective centre – the silver studs – in at least a few of the dark spots along the outer edge: you can see these in some of the images in this article. Sometimes these silvery markings are absent or missing, though, so take care with identification.
Silver-studded Blues are haunters of heathland and dunes, living in colonies and producing a single brood in a year. On the heath, their preferred larval foodplants are the various heather species, and on dunes they prefer Bird’s-foot Trefoil and Common Restharrow, among a few other Fabaceae (pea family) plants.
Did you know…?
… Like some of the other blue butterfly species, Silver-studded Blues are associated with ants, primarily Black Ants (Lasius niger). The ants help protect the eggs and caterpillars from predators; in return, the larvae produce a fluid from their tail end that is attractive to the ants.
More information and references:
Board, S., Besterman, T., Dawson, B., Goodere, D., Goodere, M. and Poland, C., 2021. Butterflies of Cornwall: Atlas for the Twenty-first Century. Pisces Publications, Berkshire.
Websites:
Butterfly Conservation
UK Butterflies
Published: June 2025
Author: Amanda Scott
Photos: Top, of male – © Natural England/Allan Drewitt; middle, of female – Frank Vassen from Brussels, Belgium, CC BY 2.0, via Wikimedia Commons; lower, of female underside – Amanda Scott