Shrivelled fruit leaves

[DominicJ]

Title says it all really, the leaves on on some of my fruits have gone a very dark green, they then seem to dry out, shrivel up, and then die.

Not the entire plant, and a minority of leaves, maybe 10%, anyone have any idea why?

Oh, fruits are black currant and red currant.

[Millymollymandy]

Aphids!

[DominicJ]

I thought insect of some kind but havent seen any, well, a couple of black ones on my nearby cherry tree.

Encourage lady birds it is then