www.ukbutterflies.co.uk

I saw this at Arnside a couple of weeks ago - it had brownish uppersides, but didn't seem to have strong enough orange lunules to be a Northern Brown Argus. Forewing underside lacks expected common blue cell spot. There were male common blues nearby, and a couple of females with grey/blue dusting on upper wings. If it is an NBA, it was a very early example

any thoughts ?

SiFenn

Yes this indeed a NBA, there's enough of the underside to be 100%. The Salmacis form/subspecies at Arnside is normally rather lacking in the orange lunules.