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I've just returned from a holiday in the French Alps - not strictly a butterflying holiday but needless to say I sneaked out with the camera a few times. I'd appreciate some help with various species but here are a few blues to begin with:-

6. and all in 4. all look like Small Blues. However, 6 certainly looks like a Small Blue, but it appears to be egg-laying on Red Clover (Trifolium pratense), which is the larval hostplant of Mazarine. Do Small Blues also use T. pratense?
7. Green Underside.
5. and 1. Common. (5. possibly Eros, but I don't think so).
3. and 6a. Mazarine. (Female and male)
2. Sooty Copper.

It's raining here and I don't have to endure watching England, so I have time on my hands.

Roger

Hi David.

You're right about the first one being mazarine.

The next is a female green-underside blue, Glaucopsyche alexis, followed probably by common blue, with an option on eros, depending on where you saw it. Male eros is easy if you see the upperside but with the variability in common blue undersides I wouldn't be confident to call it on that alone.

The next is a female mazarine and the one after that a male sooty copper. Next a female common blue or eros again.

The larger blue in the group photo is either little blue or Osiris blue. The markings are completely compatible with Osiris (and not with mazarine, which you can rule out) but the ground colour is rather too dark for a male, suggesting female Osiris (which doesn't often take minerals, in my experience) or a very large minimus. In the Alps some minimus (little blue) can be huge.

Finally, the last one is indeed mazarine.

For the eros/icarus, altitude is a factor. If you saw the upperside of the male, it will have been a rather unusual silvery blue, with broader margins than common blue.

Guy

EDIT - overlap with Roger (someone Skyped me in the middle of replying!) - but I didn't change anything so as to keep two independent views on them.

Thanks Roger and Guy, that's cleared a few things up. Hope you don't mind looking at a few more...

I suspect the first one is a female Berger's clouded yellow. I can't rule out pale clouded yellow, which is present in the Alps mostly as a migrant (but locally resident). The next is almost certainly a heath fritilary and the last one a bright-eyed ringlet, Erebia oeme.

Guy

Thanks again Guy. Finally, I have this batch of skippers, which all look like UK species but might not be:

They are all exactly what they would be in the UK - large, grizzled, chequered and dingy.

Guy

Thanks once again Guy, that's been a great help. As regards the possible eros and osiris blues, the location was Les Contamines Montjoie, around 1100 metres above sea level. Does that make a difference one way or the other?

One more that has come to light - I'd marked this down as common blue but would welcome a second opinion.

1100m would be way too low for eros. I have seen them at 1400m but they are nearly always at over 1700m, usually higher, even at over 2500m (Rogerdodge and Reverdin will know the location I mean).

Regarding osiris/minimus, osiris does occur at higher altitudes but Small (minimus) is common at altitude and can vary from minute to surprisingly large, as Guy says. It’s heavily odds-on to be minimus.

Your last blue looks like Common (icarus) to me. It’s not got chequered fringes Adonis (bellargus) and the cell spot rules out all other Polyommatus species apart from eros (for which the blue colour is wrong).

On your original series, the first blue is remarkably pale and silvery for Mazarine (semiargus) – compare with the female lower. Females are usually clearly brownish. Also the hindwing series is complete and right-angled, again normal for minimus but unusual for semiargus. The forewing markings also looked rather elongated, again an indicator of minimus whereas semiargus marks are usually roundish. However, egg-laying females know what species they are!

I agree with Roger about eros (I've been too busy over the last few days to get round to commenting, I'm afraid). It would be very unusual to see this in the Alps at 1100m.

I disagree about the first mazarine blue, though, which to me is mazarine all over and not little. Mostly, I say that on jizz, but there are details of the markings too. For example, the first and third spots from the top in the hindwing series are set much more perpedicularly to the margin in little blue and the spot between them is usually, but not always (almost always in osiris) set rather basally, making a distinct angle (close to 90° in osiris). Little blue also almost always (but not absolutely always) has a basal cell spot on the hindwing. Both features are shown nicely in this comparative photo from Lepiforum:


(Image linked from http://www.lepiforum.de/lepiwiki.pl?Cupido_Minimus)

If Roger hadn't dissented, I would have said your photo was definitely mazarine, without further consideration (as indeed I did!).

Guy

I realise that we have it very easy here in UK, when it comes to identifying 'blues'. I have found this comparison very interesting. Does anyone know of a comparative 'key', which highlights differences in the way Guy has done for mazarine/minimus?

Mike

Interesting. The semiargus in the PACA region do not resemble David’s first one. Maybe in the Rhône-Alpes they are different.

These are the main differences:
The female ground colour is distinctly brown. Even some of the males have a rather brownish tinge.
The spots are distinctly round. In minimus they are often slightly elongated.
The forewing series is always strongly arched. In minimus they are essentially in a straight line or gently curved.
The hindwing post-discal series: the spot in s6 is rarely in line with those in s5 and s7 and it is often distinctly smaller. It is rare that these marks make a clear right-angle.

On all of these scores, David’s looks unlike semiargus.

Clearly it is semiargus, as I intimated in the comment about egg-laying and I should have extrapolated this to say that it is almost certainly semiargus, but it resembles minimus more than semiargus in at least the four respects I have outlined above.

On a trip today to an upland site in Var there were maybe 20 male semiargus puddling at various spots. I had a close look at them and they all met the spotting criteria I would have expected.

Spots are often quoted as identifying features, but spots are highly variable and in many cases can only be reliable in 80% or so of cases, or in combination with other factors. For instance, the osiris hindwing s2-s5 series is often quoted as being in a straight line whereas the minimus series is said to have the s2 spot displaced basally. This is true most of the time, but not always. There are plenty of exceptions. For males, there is a much better test in the field: if it is blue on the upperside it is osiris.

Just read this thread with interest and happy memories of Roger's aforementioned site.... whilst being called over to see a female cynthia I was stalking this little gem... sort of relevant as it is the male eros showing upperside, nothing like any icarus I have ever seen
The underside, however, is a bit similar..