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Here's one from France in October. Is it just a clouded yellow or pale CY or what?



Thanks again

John

I’ll be rash enough to stick my neck out until an authoritative opinion comes along. It’s very worn and the sun is behind it which actually helps the ID as both wing borders are visible. It doesn’t seem that the borders are wide enough for clouded yellow (colias crocea), so the choice is pale CY (C. hyale) or bergers CY (C. alfacariensis).

These two are notoriously difficult to tell apart (with only the underside on view) - bergers CY was only recognised as a separate species in 1947 or thereabouts – and the books sometimes say helpful things like “cannot be separated on external features alone”, but this looks quite clearly to be bergers as the forewing apex is quite rounded and the wing edge is quite curved (pale CY has a straight edge and a more pointed apex) although there are plenty of specimens around where this doesn’t look clear-cut at all. The forewing looks white, so I’d guess it’s a female, but the transparency could be masking the pale yellow colour of the male as it is quite faded.

Pale CY doesn’t occur in the far south of France, which may help.

Thanks Roger. I'd got it labelled up as Bergers CY but I wasn't sure I'd got it right. It was taken not far from Bergerac and I agree it is worn but is was October time when I took this one. I'll go along with BCY until someone say's different.

Thanks for your input.

John