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I cannot believe this has been sitting in my Chapman's Blue file!!.Switzerland 09... I am posting it for confirmation it is indeed agestis / artaxerxes / allous?... then I will take myself to one side and administer a good kicking

It's definitely Aricia, Paul... I sincerely hope it wasn't I who misled you at the time! I remember you were keen to see Chapman's and I also remember finding and identifying one or two for you.

As for agestis/artaxerxes, that is a very open question out here. The two species seem to blur into one another so completely that a great many records cannot be ascertained. I used to be confident but now am only so with very clear-cut cases - back onto the learning curve for the time being!

Guy

Thanks Guy.... nothing to do with your ID's... I have photos of both species from there, just managed to stick this one in the wrong place for some wierd reason... and left it there.... even wierder!!. having re-filed it, it fits with a very dark upperside butterfly, hardly any orange spotting, so fresh though, there aren't any flaws to confirm it's the same one.
Takes me back !



These were my Chapman's...

Chapman's good - look at the androconia on that fresh male! And that second Aricia is clearly artaxerxes - no doubt there. I suspect the first is too - not easy to say if it's thesame insect or not but the markings are the same.

Guy

Interesting aricia, no doubting that it is artaxerxes but I have never seen one, even a male, without ANY trace of upperside orange lunules. The thersites looks quite unlike the ones I see in Var - the border is much thicker and slightly chequered and the veins extend inwardly. No doubt you have seen the underside and confirmed thersites, but I would have guessed at idas without any clues. Just goes to show how variable some species are in widely separated populations.

This is a typical Swiss artaxerxes male:



The orange lunules are usually present on the hindwing at least - and they are just visible on the hindwing of Paul's. I think somewhere I've got a photo of a darker male, but I can't seem to find it. The problem, of course, is when they have orange extending onto the forewing, which does often happen. Then, it can be quite tricky to separate them from agestis.

I agree, Roger, the blue does not have the jizz of Chapman's. I thought it looked like escheri, but thought the forewing cell region was not good for that, so I accepted the ID and commented on those fantastic androconia (plus, I was answering from my iPhone, whilst watching Yes Prime Minister on YouTube under the bedclothes )! I didn't think of idas at all, but if Paul is identifying from a photo it is possible he has forgotten what the butterfly was like in the flesh... It is, of course, impossible to mistake idas for thersites in the field.

Having just run through my own Swiss thersites pictures, I can't find any with remotely broad borders. I incline back towards escheri, but it would help to know where the picture was taken, as I probably know the locality and what flies there. Paul?

Guy

gulp... Guy, you were with me when we saw the Chapman's... in the valley of the humungous dongs, if you follow me , - I have an underside shot of the same specimen... plebejus did not even cross my mind!

Yippee! That's Chapman's. The apparent cell spot is illusory - no way it's icarus!!

Guy

It makes me wonder if that almost bearded androconial patch isn't a rather good way of identifying thersites in general, not just for separating it from icarus. The problem is, my filed and sorted piccies are always small, compressed ones, and it's a pain going back to the originals to check. It would be interesting to zoom in on the cell of escheri and idas to see what they are like.

I don't have an idas pic which would be any use, and none of my pics ever bear such close scrutiny.... but this is a definite Escher's...



and this is Silver-Studded

Interesting. That escheri looks quite fresh but it's still less hairy than thersites. I suspect the argus is not so fresh - but quite different!

Those bright lines around the cell, which often look like antlers, are classic escheri and their absence is why I rejected that ID last night. Reviewing escheri pictures, the half-chequering in that species is always more prominent than the slight effect on the hindwing of your thersites.

Funny how these species are so easy in the field but somehow more difficult from photos! I think so many other features combine in the field - the shade of blue in flight, size, habitat, nectar plants &c. My first short-tailed blue of 2009 I saw in flight some metres away and then chased it across a field because I just knew it was a short-tailed, not the usual Provence short-tailed. I've no idea how I knew! But I was right, and I found a new local colony.

Guy

Here's a photo if idas of the form calliopsis which I find quite regularly in the Alps. It has the same chequering of the fringes and the veins extend inward. In reality it is rather bluer than this, although not of the violet-blue of thersites, but I think this shot caught the light rather too well. Calliopsis is illustrated in Tolman & Lewington. Escheri did cross my mind also, but the unh chequering here tends to be more of a "cut" at the veins. In any case, Paul, you would know from seeing it in the field as escheri is appreciably larger. The underside shot (the first one, under the upperside shot) does not look like thersites to me. I say this from the standpoint that I see too many puzzling variations to be able to say anything with 100% certainty. But those marginal lunules look exactly like escheri, both the colouring (darker orange brown) and the more rounded shape compared to thersites which is more elongated and sagittate. The unh post-discal spots look too heavy for thersites to me. The black spots in the white marginal areas also look too large for thersites to me, and about right for escheri.

Against that, the ground colour is brownish, whereas escheri is usually a clean grey. On balance, I would go for escheri for this underside shot. No doubt that the second (and latest) underside shot is thersites.

OhhK.. the underside shot in question did not belong to the same individual as the ups. shot... ironically I used it 'cos I thought it was MORE typical theristes, and lacked the annoying flaw Guy commented on in the real uns. shot which went with the ups. I'm sure Guy will tell us if Escheri exists at the site... I have no ups. shots of the questionable individual... can't really remember how big that one was... quite happy to relocate if consensus is escheri.

PS... just love the quality of the photo Roger, and that goes for the nightflying SWA in the photography section!!

In my experience, that underside is well within specs for thersites and the clean margin is not good for escheri female*. I'm quite happy with the ID, though like you, Roger, I wouldn't put money on it without a glimpse of the ups. For the record, I've not seen escheri at that site. And surely that's sainfoin all around it... Escheri has no relationship with sainfoin but thersites is invariably seen in its vicinity. So, without setting myself against Roger, I still plump for thersites.

Guy

*I don't know if the butterfly is male or female, but I don't see it as male escheri since this has a much greyer appearance. Male thersites can be browner. This is a male (left) and female escheri in Switzerland this year (I mean, 2009...):



Guy

Thanks both of you... I really appreciate the discussion, I think the field has to be the final arbiter, and as such will probably leave it where it is, since my original IDs were shortly after seeing the buts. I know size isn't everything (allegedly), but I think it was instrumental originally. I'm going to scratch around for some more of my dodgy IDs to see if I can annoy you all some more..