Common Blue Butterfly

Polyommatus icarus

Photos have been downgraded in size and quality for Internet bandwidth; copyright e-barrett

For identification of butterflies, both the top and side views are shown.
Common blue topside
Common blue underside
blue butterfly top
blue butterfly side

The beautiful Common Blue butterfly, male -- Totteridge Fields, North London
blue on buttercup
butterfly on buttercup
     
Male Common Blue
Male Blue butterfly

Another male Common Blue

Female Common Blue usually has some blue scales, particularly near the body, but not always, - can be quite brown
Female Common Blue
Female Blue butterfly

Female Common Blue - brown on top with orange spots, - can look similar to the Brown Argus butterfly above,

but Brown Argus female has full set of orange "lunes" on the forewing, unlike Common Blue (and male Argus)

 Side also similar to Brown Argus but an extra spot on the forewing (not visible here)