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Silver-studded Blue

Photograph by: 
Peter Orchard

A heathland butterfly found from late June until early August on the heathland of Purbeck and surrounding areas.


  • Silver-studded Blue: a hundred eyes

    Post date: Wednesday, 10 June, 2015 - 00:00

    Dorset is home to a number of very rare butterflies and the silver-studded blue (Plebejus argus) is certainly one of them. Argus was a giant with a hundred eyes; the silver-studded blue is hardly a giant and does not have a hundred eyes on the underside of its wing but those numerous black and silver studs on the wings are almost certainly how it came by its Latin name. It is a small butterfly being smaller than a common blue and with much brighter markings on the underside of its wings. On the top of the wings the silver-studded blue has quite a noticeable black margin.

    This a species with quite a distinctive preference in habitat however, as a heathland butterfly and can be found from late June until early August on the heaths of Purbeck, notably at Arne. It also occurs on limestone grass downland and can be found on Portland. Being primarily a heath specialist, it is not surprising that its favoured food plants are gorse and broom and the larvae also feed on heather and birds-foot trefoil. 

    Blue butterflies are, in general, exquisitely beautiful insects and the silver-studded blue is certainly one of the best.


  • Silver-studded Blue in Dorset: what your tweets tell us ...

    Post date: Wednesday, 24 April, 2019 - 21:37

    With the silver-studded blue being quite common on the heaths of Dorset it is easy to forget that nationally this is a rare species. It is predominantly a heathland specialist and heathland is restricted to mainly central southern England which means the silver-studded blue is a local species. The loss of heathland habitat since the war means the silver-studded blue has declined in numbers overall but where favourable conditions are found it can occur in significant numbers. Single brooded it is seen mainly in July and early August.

    We have forty seven reports for 2017 and 2018 combined in the Nature of Dorset tweets database which shows first emergence in week 22 which is mid June and the bulk of records occur in June. There are reports for nine consecutive weeks through until week 31 early in August and peak records come in week 23 and 24 so it seems that the silver-studded blue flies a little earlier than the text books indicate; maybe it depends on the warmth of the summer sun to instigate its emergence?

    Including some survey data, the silver-studded blue has been reported on 37 sites and, as one would expect these are predominantly heathland habitats but it is also quite common on the limestone grassland of Portland as well as a couple of sites on the Purbeck coast around Lulworth. There is also a reliable record from as far west as Bridport which is well away from the main heathland further east around the Poole basin.


Common Name Silver-studded Blue
Scientific Name Plebejus argus
Species Group Lycaenid Butterflies Blues and Hairstreaks
Interest Level
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Identification Notes
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Additional Identification Notes
Similar Species

The records for this species have been organised into reports, charts, maps and photos. Click a pic below to see the detail:

Notebook Distribution Map Sites List Some Charts Some Photographs Recent Records Guidance Notes

To see related species click here: 

Lycaenid Butterflies Blues and Hairstreaks