I had a nasty case of scale infestation on some of my Catts. which began about 2 years ago. I had just moved to a new home and during my unpacking phase I had to make some hasty decisions on locating my outdoor orchids to their proper growing environment. Unfortunately I made the STUPID mistake of placing some of my Chids in direct contact with the ground under the dappled sunlight of some short palm trees. They appeared to be happy during the next few weeks as I was cleaning, unpacking, and getting settled in. Out of the blue, I noticed discoloration on the leaves...and at first thought they were receiving too much sunlight. For 2 or 3 days I moved them around and the condition got worse and after further inspection I discovered a terrible case of Scale. I'd never encountered this before so I jumped into research mode. First I removed all effected orchids from their pots and throughly treated all parts of the plant including the roots with a systemic. I repeated this treatment multiple times over the next few days and used q-tips, toothpicks, and even a water pick to coax the nasty critters out of any visible crevaces. I repotted each of them using fresh pots and potting medium. Initially I thought I'd solved the problem...but every few weeks I'd spot some minor evidence of their reappearance...and each time I'd jump into action with a systemic and spot treat with alcohol. Then I saw the article on OB about using a dilution of oil, dish soap, and water. I couldn't find neem oil so I used mineral oil instead. So far this method seems to be working. The only change I made was to follow up the next day or so with just a mild solution of soap and water to remove the oil residue. I did a follow-up treatment 2 weeks later just as a precation. It's been 3 months since their last treatment and things are looking good...but beware, "Scale", I'm still looking.