I have already suggested to Mary from what little can be seen from the photograph that I imagine her white stuff will be produced by a scale insect or woolly aphid and she is more likely to get an answer from the RHS (Royal Horticultural Society). There are no easily available keys to species in these groups and few naturalists specialise in them.
Your Forum
This forum has now been more or less replaced by the Club's Facebook page at 
The weblog below is for naturalists to use to report interesting sightings, ask questions, report on field meetings and generally post pictures and any information or questions generally relevant in some way to the wildlife and geology of Essex. You will need to register and be logged-on to post to the forum, and you need to upload pictures first, for use in posts. Find out more
The weblog below is for naturalists to use to report interesting sightings, ask questions, report on field meetings and generally post pictures and any information or questions generally relevant in some way to the wildlife and geology of Essex. You will need to register and be logged-on to post to the forum, and you need to upload pictures first, for use in posts. Find out more