peter123 wrote:

peter123 wrote:

I've had another look at the leaves and you're right, I can see
something on the underside....they appear to be small brown (1mmx2mm)
marks which run up the middle of the leaf...so I think you're
right....the brown marks also come off if I scrape them with my finger
(see picture).

The problem is that this is on every leaf and there's no way I will be
able to scrape them all off.

Nice picture of soft scale - wish I'd seen that before I posted my first answer.
I think everbody else has covered the treatment.
--
Rod
http://website.lineone.net/%7Erodcraddock/index.html
My email address needs weeding.