Posted: 16/09/2015 at 20:25
I agree with Pete - systemic insecticides will kill all the good insects, ladybirds, bees, hoverflies etc - many of which would feed on aphids next year. Kill them off and you'll have even worse problems next year.
The aphids will be gone as soon as the colder nights arrive and as Pete says it's too late in the season for them to do any damage.
Over the winter hang bird feeders with sunflower hearts near to your sambucus, to attract blue tits and other small insect eating birds - when they get used to it as a feeding station they and their fledglings will hoover up the aphids in the shrubs in the spring