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I would appreciate an opinion as to what these Blues are. Seen last week in the north of Serbia along the edge of an irrigation canal by the Danube. Despite it being an area of intensive agriculture, butterflies were numerous, feeding on the salvias that were flowering on the un-managed bits of land and road sides.

Hi Wolfson. Your blues are definitely of the genus Plebejus. Beyond that, things get more complicated. The second one looks very good for female P. argyrognomon. The first and third would not seem to be this species, because of the dirtiness of the margins, the disposition of the black lunules and the overall appearance. The first one looks most like P. idas to me and the last most like P. argus - but these are famously variable species from region to region and my experience in the Alps is perhaps not reliable for Serbia.

I'm not aware of Salvia being a hostplant for any of these species so this doesn't give a clue. In the absence of any further hints, therefore, I think you can be sure only that you have one of more of the species P. argyrognomon, P. argus and P. idas. It is not impossible you have all three but this would be quite a coup I think!

Guy

Guy
Thank you very much for your guidance. I shall study my other photographs closely.

Are 1 and 3 not the same butterfly? that nick out of the hindwing looks awfully similar...

Good point, Buggy!

So a maximum of two out of three, then! I still think the middle one looks good for argyrognomon, though with low confidence, and would probably veer towards argus for the first and third. Plebejus without upperside or any other information is difficult ...

Guy

Thank you for helping in what is clearly a very difficult genus to speciate.
I have some upperside shots that may help, I believe 4 & 5 are the same individual, 6, 7 & 8 not the same but on current form...
I spent about two hours walking back and forth over about 200 m of track so it is highly likely that the same individuals were photographed several times.

For what it's worth, I think the first three uppersides here are idas. The problem is, even in Switzerland I've seen argus with as narrow borders as this, so I really can't say for Serbia. The extent of black (that is, lack of) towards the costa of the hindwing suggests idas rather than argus. The female looks good for argyrognomon. The last male is a common blue, Polyommatus icarus.

Guy

Guy
Thanks again for your help.