In message , Jean
writes

I am having some difficulties getting rid of wooly aphids on my
phyracantha - they are taking over. I have tried pressure hosing and
various chemical preparations but they are still winning the war so any
ideas would be gratefully appreciated.

If you can still find it, and are prepared to use it then the nasty
systemic dimethoate* will probably see them off if you use it wisely.
You may need to alternate with a random contact insecticide and or meths
on a brush.

Unless you are absolutely ruthless woolly aphid once established is
there forever. It is even worse on fruit trees. I won't use dimethoate
on them.

* I think this may have been withdrawn in the UK for domestic use.

Be aware that if it kills woolly aphid effectively it is really bad
stuff. Read the instructions, follow them and wear appropriate
protective gear.

Regards,
--
Martin Brown