No good deed goes unpunished! You try to be friendly with the ant and look what he does. Will a systemic pesticide like Merit kill the aphids?

A quick hose will remove them. This is how I get rid of them off my roses. Hold the plant while spraying.

Winter I use Merit granules year around on the broms and have great results no bugs, I also use a systemic spray several times a year. In the greenhouse floors I also use lawn insect granules to keep the snails etc out

Yes, I treated with systemic (carbosulfan) spray, it's also work for scale insect too.