Elaine a couple older plummies of mine have these and they only showed on leaves that are ready to fall off and had rusts.I think it was for me too hot (lack of watering) but they look a little better after we had a few days of rain.
Ken I never did get around taking the photos with rust, been raining here, but rusts look like the yellow bumps on Ellaine's pictures. You are very lucky if you do not have any. For my area, more rain means more rust too.
