Distribution of Provencal Short Tailed blue in France

[Sylvie_h]

I spent 2 weeks and a half in the Savoie and Haute Savoie recently and was surprised to find some Provencal Short Tailed Blues in the Combe de Savoie (area between Montmelian and Albertville).
They were found in small numbers but always on places facing South (low altitude ~400m) and near their foodplant (crownvetch) although never on it.

Looking at the distribution map on Tolman, this butterfly is very much a southern species in France and the French Alps are not covered. I have never seen this butterfly further North in the Haute Savoie.
I would be keen to read comments from the specialists on France and what their experience with this species is.
Thanks
Sylvie

[David M]

Well, Roger commented on how Provençal Short Tailed Blues were missing from the Alpes-Maritimes, so to find specimens so much further north does pose questions.

[Padfield]

Kudrna's 2011 Atlas shows alcetas throughout the southern half of France, north to roughly the latitude of Geneva in the east and further north further west. The more detailed maps in Lafranchis 2014 (Papillons de France) show a more broken distribution but covering broadly the same areas. Certainly, in the Alps of Switzerland this is a very common butterfly, to be found pretty well anywhere up to an altitude of about 1000m and locally higher. It is a beautiful and always welcome species but definitely a 'background' butterfly, like common blue or brimstone, that accompanies most excursions at these lower altitudes. The last time I drove with my parents from Switzerland back to the UK - some years ago now, as they always fly these days - I found it near a service station well north of Switzerland.

Historically the records do not show such a widespread or common butterfly. Tolman's maps haven't been updated since the book came out about 25 years ago ...

Guy

EDIT: From Christian Perrein's Biohistoire des papillons (2012): "C'est une des rares espèces à connaître en France une importante augmentation de son aire de répartition vers le nord, en évitant, semble-t-il, les massifs anciens".

[Padfield]

PS - I just noticed your reference to the foodplant, crown vetch. That surprised me, because I hadn't noticed any association with that plant in Switzerland. The butterfly seems to use a wide variety of vetches, including bird's foot trefoil, and flies in places where there is certainly no crown vetch. Maybe a broader foodplant tolerance is behind its recent expansion.

Guy

[CFB]

Hello Guy,

Thanks for mentioning Lafranchis 2014 (Papillons de France). I didn't know it existed. I ordered a copy straight away .

Sylvie, please excuse me for jumping into your thread.
--
Colin

[Sylvie_h]

Thank you Guy for the reply. You are a mine of information !!

The first time I saw and photographed the PSTB was near Carcassone several years ago, it was feeding on minerals on the ground. Since then I had not seen it so it was wonderful and totally unexpected to find a population in Savoie. I thought it was a species of low altitude but if you have it at 1000m or higher in Switzerland, I will have to look harder and try to find it in the Hte Savoie when I am there.

Is Biohistoire des Papillons worth having? I have looked on Amazon France and saw that it covers Loire Atlantique and Vendée only rather than the whole of France. I am very much interested in the biology of the butterflies in France and would like to find a book with details of each species but I am not sure if such a book exists…..

Colin, no problem ! I see that you live in Valbonne, I know the area very well as I’ve lived for 3 years very close to Valbonne (I was in Le Rouret). A beautiful area with lots of butterflying opportunities… although at this time of the year everything is dried up….
Sylvie

[CFB]

Sylvie, yes, dried up and very hot.
--
Colin

[Padfield]

Hi Sylvie (and Colin). For the biology, rather than identification, of the French butterflies, I suspect Lafranchis's latest book (http://diatheo.weebly.com/la-vie-des-papillons.html) is the must-have. I haven't bought a copy yet, mainly because I've been buying so many other butterfly books I haven't got any room left in my budget. Although I've never met Lafranchis I have communicated with him on several occasions and he is a very knowledgeable man, not by virtue of study so much as passion and experience in the field. I would expect this new book to contain completely original insights into the ecology and biology of the species.

Guy

[Matsukaze]

It was recorded as far north as Le Mans a few years ago. If it continues to spread it should reach the Channel coast within a decade. Not sure if they will cross large stretches of water (it isn't on many of the European islands) so I doubt it is a potential colonist of southern England though.

[Sylvie_h]

Thank you all for your contribution and replies.
Guy, thank you for the recommended book on the biology of butterflies, I 've had a look and it looks wonderful indeed.
Sylvie

[Roger Gibbons]

Just seen this thread - very limited internet here (Dordogne) - it is Short-tailed Blue (argiades) that is absent from PACA. I am back in the UK on Thursday and will have a look at my and other records for alcetas and respond to this track.

It is alcetas that I see regularly these days and argiades is a rare sighting but I am visiting a couple of sites here today and hope to see it this afternoon.

Roger

[Chris Jackson]

Hello Sylvie, Hello All,
Just for info, and for what its worth, I have seen neither Short-tailed Blue nor Provençal Short-tailed Blue in the area of Marseilles.
However, I saw this female and this male in close proximity in 'Parent', near Clermont Ferrand, in the massif central, last summer.
I presume Short-tailed Blue ?
female

argiades1_63 female Parent 08 July 2014 (1).JPG (50.08 KiB) Viewed 703 times

male

Cheers, Chris

[Sylvie_h]

Hi Chris,

I am not sure about picture 1 and 3 but I am pretty sure that number 2 is ProvencaL Short Tailed Blue. The abscence of orange on the underside (or very faint orange marking) is a good indication for this species. If the orange fills the space between the spot and the 'chevron', you can assume that is Short Tailed Blue (argiades).
Hope this helps...
Thanks
Sylvie

[Padfield]

I would say all three are alcetas. As Sylvie says, the second one leaves no doubt. But the first and third leave very little. Female argiades usually has at least some blue scales on the upperside, while female alcetas is rather sooty brown all over, with perhaps a bluish patina as in the first insect above. The tail is also longer in argiades in both male and female. In alcetas it is usually reduced to a few longer hairs and is sometimes vestigial or even absent. In argiades it is visibly a tail.

This is female argiades, photographed today:





Guy

[Chris Jackson]

Sorry, how dumb of me not to point out that photos 2 and 3 are in fact of the same individual.

Thanks, Sylvie and Guy. I will thus correct my archives.

Chris

[Roger Gibbons]

I saw Provence STB (alcetas) at La Rosière, Savoie (alt 1450m) on 19 July 2012. Other than that, my records (of 20 separate locations) are mainly from central and western France, generally not further north than Lyon. I often find it at medium altitudes and saw it this year at the Col de Negros (a single female) in the Drôme at an altitude of 1240m. Last week in the Dordogne, it was reasonably plentiful. I have seen alcetas in the Hautes-Alpes, a long way from any records according to the PACA Atlas; similarly I saw one in the Alpes-Maritimes (1000m altitude) on 26 June this year, also in a region devoid of previous records. I think alcetas is under-recorded as it could be mistaken for Common Blue in the field.

The elusive species, for me at least, is argiades, which I have seen in 14 locations, but most of my records are from the first half of the “noughties”. It may be that I’m not in the right places at the right time, but when I am travelling in central France, it is alcetas that I almost always encounter.

I have a copy of Lafranchis' La Vie book which is accompanied by a detailed distribution DVD, but I thoughtfully left it in France. I'll check in September.

I’m inclined to suspect that alcetas is expanding in range and argiades contracting, and this seems to be the experience of others.

Roger

[Sylvie_h]

Thank you Roger for this information. If Alcetas is expanding, then surely the name of "provencal" is not appropriate anymore.
Over the years I have spent butterflying in the region, it is actually argiades (STB) that I have seen more often.
Thanks again for this interesting insight.
Sylvie