cliff_the_gardener wrote:

It is hard to day without seeing it but sounds like a plum leaf curl
aphid. It is a common pest that affects all plum - gages & damsons.
Picture on the RHS site at
http://www.rhs.org.uk/advice/profile...plum_aphid.asp
Does it look anything like this?

I noticed my damson tree with similar symptoms this weekend.

Many leaves curled up with small colonies of creatures inside covered
with a white hairy layer.

From reading this thread I assumed it was plum leaf curl aphid, but it
looks much more like mealy plum aphid from this page:
http://www.ipm.ucdavis.edu/PMG/C611/m611fpaphid.html
Certainly the leaves aren't nearly as curled as the picture on the
right, and the creatures were covered with a white layer.

But that is an American site. Do we have mealy plum aphids in the UK,
and do they commonly affect damsons?

Peter