Found these Oak leaves last year with some kind of discolouration, any udeas please.
It looks like Oak Leaf Aphids (Phylloxera glabra).
Hi there, thanks very much indeed, a really great help.
you might be interested to know that the pattern of discolouration around each of the aphids in image 1c is due to the contents of those cells having been sucked out by the aphids.
A random factoid for you! ;-)
Thanks very much Jen for your reply, very much appreciated.
All the best.