cottony cushon scale

How do I get rid of this pest? These nasty little guys love to line up on the stems of my hosta flowers, my lilies, and my coleus! I tried blasting them off daily with water. I tried neem oil. So far nothing is really working. Any advise?

Hi, I hate this scale so much! Haven't had to deal with it foe quite awhile, but thought I would do a internet search on it. Found this great web site-
/www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7410.html
It pretty much says insecticides don't work, and if you were to apply 'Merit' it not only doesn't kill the scale it WILL kill the predatory beetle that is the best control!
Hope this helps! kim