I have a bamboo palm, which when i first bought was infested with mealy bugs. Over a period of two months I have regularly used rubbing alcohol to reduced the infestation as much as possible. And now it is very hard to find one, sometimes I have to really search in the nooks and crannies .
Now that the bugs are almost gone I have started paying attention to the white patches found on the underside of the leaves (picture below). At first i thought it was because of the mealy bugs but since they are almost gone I think there might be another reason. I was hoping if someone can help me identify the cause for these patches? (they look like water stains, pretty flat)