Adonis Blue and Common Blue, how do you tell the difference?

[StRoRo]

Im sure you have had a million and one questions about these 2 butterflies.

I took the picture below and I'm trying to find out which butterfly it is. I have had a look at both the Adonis and Common Blue and I cant tell the difference.

Its most probably a Common based on the how "common" they are and my geographical location, but what is the difference? What is the best way to find out the difference?

[aeshna5]

Shame you didn't mention your geographical location. Anyway this is a pristine male Common Blue; the Adonis is more brilliant + has black lines through the margin.

[StRoRo]

Originally Posted by aeshna5

Shame you didn't mention your geographical location. Anyway this is a pristine male Common Blue; the Adonis is more brilliant + has black lines through the margin.

Ahhh does help.
North West England.

[aeshna5]

Originally Posted by StRoRo

Ahhh does help.
North West England.

Yes you are very unlikely to see Adonis Blues there- you'll have to come south!