Roses with a problem

Have noticed this for a couple of years and sprayed the roses,but the white insect stuff is on the new growth too.
I have no idea what to use now..I have used Rose Clear and also diluted Washing up liquid!

http://i158.photobucket.com/albums/t96/blueboy8_photo/GC002_edited.jpg

 

I usually reckon to spray about every two weeks, more frequently if the bug(ger)s) don't go quick enough.