Raspberry canes Leaf

I desperately need help identifying this calls what's making the leaf curling also marks on the leaf hope somebody can help me as I'm racking my brain is here

Is it progressing gradually, throughout the canes?  In any case, I'd remove the damaged parts and put them in the trash.
Has roundup been used in the area?  Here's a link to an American site that has pictures similar to yours. Scroll to the bottom of the page.
http://www.fruit.cornell.edu/berrytool/raspberry/leavesstems/Raspcurling.htm

I wondered if it was an aphid problem but, having had a look at a couple of good books, am thinking like the others to give them a good soaking and also a good feed with Tomorite or similar as the new growth looks very pale and spindly.