What is this?

[VVATC2017]

Just bought a Mandevilla and it has white spots on the leaves. Looks like something was sprayed on them and left water spots. Is it powdery mildew or could it be some kind of preventative that was sprayed?

I attached a pic of a leaf (front and back)

 

[Chuck]

Just bought a Mandevilla and it has white spots on the leaves. Looks like something was sprayed on them and left water spots. Is it powdery mildew or could it be some kind of preventative that was sprayed?

I attached a pic of a leaf (front and back)

I don't know but to be on the safe side I would spray it with 1 heaping tablespoon baking soda to a gallon of water a a preventative for mildew. What it looks like is the person you bought the plant from misted it with a soapy insecticide of some sort but I don't know for sure.