ants and aphids

My broad beans are absolutely full of blackfly. I ran round the plot picking up as many ladybirds as possible (after pinching the tips out) and putting them on the broad beans. They started eating the aphids, until the ants started attacking them.

Done a bit of research and after seeing that my broadies are covered in ants aswell, it seems that they 'farm' the aphids for honeydew which they excrete! So all the ladybirds have gone!

Anybody else noticed this funny relationship with the 2, i thought the ants were doing me a favour at first and eating them rather than protecting them!

Little story about ladybird larvae.   Some years ago there was a plague of ladybirds, they don't do any harm but the local farmer sprayed every crop to kill them off.  Next year wheat, barley, oil seed rape absolutely infested with greenfly.  Had he kept his sprayer in the barn he could have saved an awful lot of money.  Nature does know best.