I have bright yellow 1/4 to 1'2 inch diameter spots on bright green rose leaves. What is it and how do I treat it? Thanks.
It sounds like some sort of burning rather than insects or funguses. I have seen such things caused by spray drift. Spraying weed killers or even some insecticides and the spray drifts over onto the roses foliage. I also have seen this happen when the roses were sprayed with an insecticide during cool cloudy weather and it sat in droplets upon the foliage too long. Another thing can be cat or dog urine that has sprayed up onto the foliage. Rinse the foliage all off with a water wand watering device on the end of the garden hose and hopefully you will not see any more of it. If none of the above seem to be the issue let me know and I will look into it some more. Send some photos too if you can.