I saw and photographed this butterfly earlier today (Sunday 26th Feb) and it seems to me to be a gonepteryx, but which one? Is it Brimstone, Powdered Brimstone or Cleopatra?
Points of interest to me are the small subsidiary dark spots on the hind wing. My identification book shows no such spots on Brimstone or Cleopatra. Also the antenna has a white club and dark tip. Are these features collectively or individually significant in identification? I don't wish to state at this stage where this was seen in case that prejudices the identification process. (There is obvious damage to the forewing and I guess this confirms that this butterfly is not a new brood but has emerged from hibernation.) I am most interested in any comments as I am a novice at butterfly identification, but keen to learn.
Your pic is not a powdered brimstone on two main points. The anntenal clubs on a Gonepteryx farinosa are pink and farinosa is only in the southern Balkans, especially Greece.
I doubt that it is cleopatra because with the wings closed the large orange splodge on the upper surface of the fore wing may show through.
I would bet on G.rhamni.
My book (Collins Butterfly Guide) seems to point to Gonepteryx rhamni. G. farinosa has scalloped hind wing margin, unlike G. rhamni. G. cleopatra seems much paler than G. rhamni to me, and also the pattern of colours on the front wing is difefrent: the front part is darker in G. rhamni and lighter in G. cleopatra. The dark spots that you mention (I think) are present in all three species. To me it looks like G. rhamni has the most obvious 'tail', and also the most pointed and recurved front wing tip. The overall colour seems to be green(ish), while the other two species are more yellow or white?
I've made a composite imege so you can see the three species together with your specimen, so you can decide. You can also compare it with the two images on UK Butterflies website.
I hope this helps.
Thanks indeed. Seems I need a better book. I'm interested that my book makes such a deal about the colour of the club but yours (I assume) doesn't. And thanks for the website link - I've tended to be suspicious of websites because what's to stop someone posting a mis-identified image? If you Google images of wildlife there's masses of photos of birds, butterflies and other wildlife with labels and I'm willing to bet many of them are incorrect. It's good to know of one that can be trusted.