I have a zuchini squash plant, it seems to have aquired these white spots on the leaves.?

It doesn't seems to be powdery mildew since I can't rub them off, then the spots turn black or brown. I took some leaves off, then all I had was to spray them with soap and water. That seemed to help a bit. I also noticed that my Miniature fig tree had some on it also. So I am wondering what they are and what I can do to stop it. That doesn't involve Poison. Thank You