Gynandromorph

[Terry Rodbard]

Whilst  photographing butterflies on a recent trip to the Spanish Pyrenees,
I came across what I believe to be called a gynandromorph.  I'm almost sure
that it was a Common Blue, (Polyommatus icarus) and fortunately the photo
taken shows clearly on the left upper side,(both fore and hind wings)  the
brown, female colouration; and on the right, the blue colour of the male.
I believe this variation is caused by an abnormality in the sex
chromosones, and to be quite rare.
I would be most interested to know just how rare this is, and of any other
observations by members.

Terry.