Blackfly and Ants - Help

[cheops]

My dwarf beans and runner bean plants are doing well but the amount of blackfly covering them is horrendous. And ants are among them and running up and down the stems. The blackfly are a problem on many other plants including new shoots on the blackcurrant bush etc too. Earlier in the year I did spray the infected areas but they just come back. Now I see lots of ladybirds on the bean plants [and I mean lots] but they obviously just can't cope but because of the presence of the ladybirds I am very reluctant to spray and kill them too. What are the ants doing? Are they harming the plants or are they helping to kill of some of the blackfly? What should I do? If I leave all alone will the ants or the blackfly do serious damage? Advice much appreciated.

[Snadger]

Nip off the young tips of the beans to cut offf the blackflys food source. I think the ants will be harvesting the honeydew secreted by the aphids!

[Two_Sheds]

Yes, Snadge is right. The ants protect the aphids, and lick honeydew off their bodies. Get rid of the blackfly and the ants will go too.

Squish them, with gloves on, or wash them off with a jet of water. You MUST keep on top of this, because they breed faster than rabbits and will move onto your other crops too. I had a bad outbreak a fortnight ago, but kept squishing for a couple of days, and now they are under control ~ the ladybirds are eating them now.

[rustylady]

As Two Sheds says, either squish the blackfly (you can use rubber gloves if you're squeamish) or blast them off the plants with a pressure sprayer (Even the little ones from the pound shop work).

[CarolineW]

I'm by no means an expert, but I was advised to use a sprayer with a tsp of washing up liquid or liquid soap mixed with 1 litre of water. It harms aphids but not the beneficial insects (I was assured). I have a sprayer from Poundstretcher which I'm using for this, and I'm using Ecover washing up liquid. I have to say that as long as I stay on top of the spraying (every day while it's bad, then regular checks and spraying when I see them coming back) it's working very well. The number of ladybirds is gradually increasing, so it obviously can't be hurting them.

This has worked very well for me, but I'd be interested to see if someone who knows more than I do thinks that it's actually a bad idea. I don't want to be doing anything harmful. However, the allotmenteer on the plot next to me, who's also organic, says that it's absolutely fine, and not to worry.