Brown argus or female common blue?

[Ian Pratt]

Richard Lewington ( whom I respect greatly) says in his book "Identifying Butterflies" that the brown argus has no trace of blue on either side. I saw and photographed yesterday a small brown and orange butterfly which is clearly a brown argus due to the double spots on the underside of the rear wing and its body was visibly bluish.
Is Richard Lewington correct or is there often some blue on brown arguses?

[Denise]

Same question. I was looking at this butterfly at Sand Point where Brown Argus is abundant. I was confused by the amount of blue on it.
Is it a Brown Argus? ( sorry about the quality, but it just wouldn't play ball)



Denise

[Pete Eeles]

Hi Denise - yours is definitely a female Common Blue.

There is a "hint" at blue on a Brown Argus - see http://www.ukbutterflies.co.uk/image.ph ... May-04.jpg

On this photo the "hint" is on the underside at the base of the body.

The also exhibit a "sheen" that can also give the illusion of blue. See http://www.ukbutterflies.co.uk/image.ph ... Jul-05.jpg

But, in general, I'd say that they have no blue (if you look real close)!

If you did definitely see some blue on the body, then I'd say it's a female Common Blue. I'm not sure what you mean by the "double spots" - could you share the photo?

Cheers,

- Pete

[Denise]

Thanks Pete.

I am trying hard to learn about female 'blue' butterflies.
What about this one? Am I right to think that it is a Brown Argus even though it has blue hairs?



Cheers
Denise

[Pete Eeles]

Yes I think Richard Lewington must be referring to the wing scales in the quote above.

Cheers,

- Pete

[Ian Pratt]

"No trace of blue on either surface" is the exact quotation.
See photographs attached which are clearly a brown argus.

[Ian Pratt]

Second photograph of the same butterfly.

[Charles Nicol]

i also find it difficult to tell from the upper view if it is an argus or a blue... here is one i saw yesterday... its furry bits have a blue tint



Pete's hint about the extra spot certainly helps when the wings are closed

Charles

[Padfield]

Brown argus also has a clearly defined black discal mark on the upper forewing (on common blues this never looks so neatly demarcated) and clear black half-chequering on the wing margins (as opposed to at best dark grey half-chequering on a fresh common blue).

Charles's butterfly is definitely a brown argus, showing both the above characteristics clearly.

Guy

[Padfield]

Another point worth noting is that all the brown arguses on this page, with the blue hairs, are clearly male butterflies (from the abdomen). It should be possible to sex the butterfly even if the wings are very tatty and the markings worn thin - and a male obviously can't be a female common blue!

Pete, I think Ian is referring to the Aricia 'colon', which is clearly visible in his butterfly and rules out Polyommatus.

Guy

[Ian Pratt]

Thanks for all the contributions. It now makes identification much easier. Thanks particularly to Peter and Padfield.

[Charles Nicol]

thanks to Guy for helping

charles

[eccles]

The blue referred to on a female common blue should specify blue scales as opposed to blue colouration. Unless it is badly worn, a common blue female will always have at least a smattering of blue scales on the wing uppersides.