Blackfly

This year, after years of squirting with savon noir or squishing by hand, I just ignored the ones on the broad beans and after about ten days or so they'd been largely consumed. We did have a lot of ladybirds already in place, but also found hoverflies moving in and laying eggs. Black caps and tits had their share, too. No idea if I was just lucky this year, or previously I've been squirting/squishing the predators as well. But saying that, we don't have lots of ants - some, but not huge numbers.
There are some on the french beans this year, but none on the dahlias.
I tried putting jam down one year, the idea that after a really sugary feed the ants prefer meat to the honeydew the aphids produce, but it didn't work!
Sorry, not much help