philo xanadu leaf spots
I just got this plant and did not notice anything wrong in the shop. but in sunlight I saw strange little brown spots on the underside of the leaf: they are hard, not scratchable, not insects of any kind. on the top side they appear as small yellow spots. underside of the leaf sometimes has streaks of darker color like bruising.
spots are not mushy or wet, not blisters , just tiny hard flecks, like smallest scale, but it's not scale. in the sun you can see the spots clearly.
I am guessing it's smth bacterial? I submerged the plant in soapy water with a tb of peroxide. then sprayed with neem solution. cut off the oldest leaves which were yellowing a little. I will sprinkle systemic (imidacloprin) on it too.
any idea what it could be? I am keeping it separate from other plants. I want to cut off the worst affected leaves. the young ones seem to be ok for now.
very hard to get a close up.