The 'trick' I mentioned was something I read in the
Guide to the Butterflies of the Palearctic, Nymphalidae part II. It mentions that the mark in s.2 is typically well separated from the end of the cell in
napaea but touches it or almost touches it in
pales. This generally fits my own photographs, though some need a little imagination, and adds to the armoury of ID tips for these two species (in regions where pales is
linear). The picture on the left, below, is yours - the picture on the right is
pales from my own mountain:
I haven't really road-tested this feature, though.
I'm very unsure about the
Pyrgus - perhaps someone else will be more confident. I wondered about
cacaliae, but on that closer view it seems to lack the characteristic grey hairiness of
cacaliae. A very weakly marked
serratulae strikes me as a possibility too, or even an extremely weakly marked
alveus... The cell markings don't look right to me for
alveus. I guess
warrenensis is another possibility, depending on where exactly you were.
This is a fairly worn
cacaliae, showing what I mean about the grey hairs. But they may simply be worn off in yours.
Cacaliae is easily confirmed from the underside.
I'm not 100% on the
Erebia either!! I'm hoping someone else will join the conversation and give their view!!
Guy
PS - a date and location would help
