Common Blue ab. postradiata Photo: Mel Bray

Mel sent in this photo posing the following question:

“When I took this shot of a Common Blue at Badbury Rings on 30/05/2026 I was surprised to see that the underwing markings were quite unlike anything I’ve seen before. It may be a completely unique example. Be interested if anybody has a name for this particular aberration”.

As I was unable to answer Mel’s question myself I referred the photo to one of our verifiers who has now responded as follows:

“That’s an amazing aberration and after a bit of research seems very rare. Only found one picture that was similar but did get this description.

A Common Blue (Polyommatus icarus) aberration postradiata is a distinct and rare underwing variation where the basal spots and the black submedian spots on the hindwing are elongated and fused into dark streaks or rays that extend towards the outer wing margin”.

Editor’s Note:  My thanks to Nick Urch for his research work which provided the name for this aberration.