I have been batteling brown scale with non systemic methods, physical removal, alcohol, soap, oil and malathyon all was used at one time or other. I thought I had everything under control until I noticed new scale on a few plants I was sure were clean.
I've had it with these little buggers, I'm reaching for the nuclear option and treat the entire collection with a systemic. California is very restrictive, nothing of note can be bought off the shelf but using the internet, anything from WW1 mustard nerve gas to yellow cake uranium can be ordered up.
I was planning to use Orthene which I have used in the past sucessfully but before I do would like to hear which is your favorite systemic and why.