Answer: The missing parts of the leaves, in a half moon pattern, is due to leaf cutter bees. They cut off the tender new leaf parts to line their nests. Soon they will stop and the leaves your roses produce next month should remain perfect. There's nothing you can do about the leaf cutter bees except to know they will finish cutting half moons out of your leaves by mid-May. The white powdery substance is a fungal disease called powdery mildew. It occurs when days are warm and nights are cool and when there is poor air circulation and/or not enough sunshine on your roses. You can hand pick the affected leaves or you can spray your roses with Funginex to help control powdery mildew. Ortho liquid is an insecticide, not a fungicide so it won't stop the disease and it won't affect the leaf cutter bees. I'd put it away and use Funginex instead.
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