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Is this a male adonis blue or common blue? I plump for adonis as it's on horseshoe vetch!

Alexandra

Hi Alexandra,
That's a Common Blue.
Neil

Thanks neil. What's the difference between the two?

Hi Alexandra,
Adonis Blue
Common Blue

Look closely at the wing margins. The Adonis Blue has black markings which cross the white borders and continue into the blue part of the wing. To the more experienced eye the colour is a giveaway, but rather subjective (and variable). The AB is more of an 'electric turquoise blue' - I would describe the CB as a 'lilac blue'.
Neil

Completely agree (unsurprisingly!). The "chequered fringes" of the original photo are actually caused by the loss of scales in very specific areas that could cause confusion.

Cheers,

- Pete

You can occasionally find a Common Blue like this, where the black lines on the veins are very strong and extend into the fringes - but still not to the edge. However, in this case the location completely ruled out Adonis (Totternhoe, Bedfordshire).
The bright chalk background has reflected light up through the wings, distorting the colour, but it still shows the violet tinge Neil refers to.

Dave

Thanks guys, that was a big help!

Alex

Just a final point: the fringe of the common blue is always divided into an outer and inner half. The inner half is usually a darker shade, giving the fringe a two-tone appearance, and may be chequered, as in Millerd's shot. The outer half is never chequered. In Adonis blue there is no two-tone effect (the fringe is pure white) and the darker/broader chequering is on the outer half of the fringe.

Even very damaged or washed-out individuals are identifiable if a small piece of fringe is visible.

Guy

Same question...Common Blue or Adonis Blue? Photographed today (19 August) at Lankham Bottom, Dorset....

I'd say Adonis for all of these. The chequering is just about visible, and the colour tends to the turquoise.

Any other offers?

Dave

Agreed.
Neil

I'm not saying anything
(but I would have said Adonis)
Cheers

Lee

I've only just noticed all three shots are of the same butterfly... Good thing I didn't say one was different

Dave