www.ukbutterflies.co.uk

I was in the Ashdown Forest on ground near B2026 car park at Kings Standing
(grid ref. TQ 474298) at approx. 1330 on Sunday 24 August.
The weather moderately sunny, warm.
The terrain is high exposed open meadow, including a good deal of clover.

My attention was drawn to bright lemon yellow butterfly on the wing,
which later settled some 1 metre away.
I had no camera (grr!)

The colour was reminiscent of a male Brimstone, Gonepteryx rhamni.
However the wing shape was clearly that of the Colias species,
and there was a little black on the wingtips.

The colour was much too pale for a Clouded Yellow, C. croceus
and too dark for the form helice; I have seen both.

It seems to me this only leaves the males of
the Pale Clouded Yellow, C. hyale or
Berger's Clouded Yellow, C. alfacariensis
which clearly I would not have been able to tell apart in these circumstances.


I am aware that migrations of Colias spp. tewns to occur in "years" as with the
Painted Lady. Have there been any onter reports, and is my logic as above valid?

Hi Malcolm,

You've probably stumped the experts on here with the absence of a photo.

There are some species of butterfly that I always think look fresh when in flight, but when you are lucky enough to photograph them and view them later, you realise they are quite old and worn. The Clouded Yellow is one of these. Probability-wise, you may simply have been witnessing a faded Clouded Yellow. The other Colias species are so rare, it's difficult to offer another explanation with any confidence.

Hi.
Was your P. clouded Yellow like this one? I captured this in August
This one had a white sort of patch on the wing as you can see and was much paler than the others I have seen this month which are in a thread near the top

The butterfly above is a Helice form of Clouded Yellow.

you can just see the forewing broad black margin and spots that are on the upperside showing through both the other species have a much narrower black band.

on my laptop screen if you look at a lower angle this band shows up even more.

Oh right.
Thank you . I rarely see these butterflies and this one looked a little different with the whitish patch so I thought it might be the one Malcolm was describing

Sorry

Hi all,
It's worth mentioning that helice and related forms come in a variety of hues and shades. The dark border pattern on both fore and hind wings is critical to identification, requiring either a back-lit or open wing (!) image to seal the deal for recorders in the UK. PCY and BCY are extremely rare beasts here, but always worth looking for in very good years, the last being 2009.
BWs, Neil

I was lucky with my 1996 sighting at Noar Hill as it was a male Pale Clouded Yellow, and was also seen by the site recorder, there were also plenty of helice flying at the same time. With a male sighting of either there is no doubt, you just have to work out which of the two rarities it is.

Hi MrSp0ck,
You were lucky to get a male . As you say, a male PCY/BCY should be easy for the more experienced, at 30 paces. This is one species of vagrant I'm yet to catch up with. One day!
BWs, Neil