www.ukbutterflies.co.uk

This one had me puzzled last week, up near the village of Llo in the French Pyrenees (approx 1,500m).

Was a decent size and it looks wrong for serratulae, so I'm wondering whether it may be the accretus form of alveus.

Anyone offer any suggestions?

I would opt for serratulae. There are indications from the underside, and the upperside, whilst a little odd for serratulae, is not abnormal for this highly variable species.

As for accretus, my understanding is that this is more heavily marked and quite far removed from nominate alveus. But who knows – there is so little information on accretus.

Roger

Many thanks, Roger. Serratulae vs. alveus is always the trickiest of Pyrgus conundrums for me.