Kentucky_Rose,

Those are wooly aphids.....a little harder to control than smooth aphids because their 'wool,' resists insecticide. Spray with Bioadvanced Complete Insect Killer. It is systemic, so it kills as they suck rose juices....very effectively. 1 tbl./gallon water, and again in 10 days....that should do the trick.

Moses.

Moses, thank you! Bayer Complete is what I use in my routine spray. Are the wooly aphids more heat tolerant?

That I don't know. I do know that wooly aphids were part of the reason I removed a young semi-dwarf golden delicious apple tree that I was training into a weeping habit. It got infested with the wooliest wooly aphids you ever saw. The only way they could be killed off was to use a systemic insecticide. This would render the apples toxic, so out the tree came.

Moses.