Buxus Trees

Hi
I have two Buxus trees about 2 feet high and the keep producing like I can only describe it as snow flakes or cotton wall on the tips of the branches, can anybody please shine any light on this and would anybody know of a cure?
Many Thanks
Ray

 

I'm thinking it just might be woolly aphid, but its not something I've ever encountered myself.

 

Funnily enough, I've noticed the same on some box plants I've got in tubs. My suspicion is that they are woolly aphids, which is strange as I've never come across them on Buxus before. I try not to kill anything but I'm wondering if a squirt with a bug gun may be the only solution. Done with compassion and regret, of course.

Chris