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Hybrid or Aberrant

Posted: Sun Sep 30, 2012 2:46 pm
by Paul Wetton
My Mum took these pictures in Aveyron in France this year in June and I was asked what species it was.
Unknown Blue 1.jpg
Unknown Blue 2.jpg
I have absolutely no idea.

Firstly it has a cell spot indicating Polyommatus Blues or something like Adonis or Chalkhill. The latter two were ruled out as there is no chequering of the white margins.

The upperwing colour resembles most a Turquoise Blue slightly shiny and a bit turquoise.

The underside has no orange which could always be an aberration thus making the hindwing look like that of Amanda's Blue but totally lacking orange.

I ended up thinking either Eros Blue from the underside but with an unusual upperside colour and no thick dark margin or just an aberrant Common Blue lacking orange on the underside with a slightly unusual upperside colour or was it a hybrid. Can Common Blue and Chalkhill Blue hybridise?

Any help and thoughts would be appreciated.

Re: Hybrid or Aberrant

Posted: Tue Oct 02, 2012 9:32 am
by Paul Wetton
Any thoughts anyone. Guy or Roger.

Re: Hybrid or Aberrant

Posted: Tue Oct 02, 2012 11:47 am
by Roger Gibbons
Of the Polyommatus species, only Common (P. icarus) and Eros (P. eros) have a unf cell spot. As we can see the upperside, it almost certainly is not eros.

I don’t think it is a Lysandra species, Chalk-hill (L. coridon) or Adonis (L. bellargus), the latter because of the absence of fringe chequering. These two species have been known to hybridise (polonus? – no books with me here) but extremely rarely. I doubt whether a hybrid of a Polyommatus and Lysandra species could occur.

I think it is just a worn and faded icarus. You can see signs of wear in the first photo and the orange scales seem to get lost first (c.f. how Festoons, for instance, lose their red and blues scales first). Plus icarus is a very variable species in France.

Re: Hybrid or Aberrant

Posted: Tue Oct 02, 2012 12:32 pm
by Paul Wetton
Thanks for taking a look Roger.

I came to the same conclusion even though the upperside colouration didn't appear quite correct for icarus but as you say there is huge variation in this species.

It actually looks very similar to a butterfly I filmed in Bulgaria found in a lowland dry grassy area and the conclusion was the same a slightly aberrant or discoloured Common Blue.

Thanks again.