Blackfly

[MelanieSW]

I wonder if killing the ants in the area would help.

David

Not having any ant nests nearby should certainly help. For next year I am looking at nematodes against ants (they only deter and won't kill the ants, so that they set up home somewhere else).
Nemasys sell those, and I intend to treat the whole allotment with it!
I always have quite a few ant nests and usually just leave them be, but this year the blackfly were just too much.

[Snadger]

They are not the same species.
The so-called black bean aphid will feed on many different species, not just beans, but cherries are attacked by their own special type of black aphid, the cherry blackfly.

I realise that now. I googled it after posting.

[Deltawhiskey]

I wonder if killing the ants in the area would help.

David

[ameno]

I have blackfly on my patio cherry tree but not sure whether these are the same blackfly as on beans?

They are not the same species.
The so-called black bean aphid will feed on many different species, not just beans, but cherries are attacked by their own special type of black aphid, the cherry blackfly.

[Snadger]

I have blackfly on my patio cherry tree but not sure whether these are the same blackfly as on beans?

[Jeremy424]

My sympathies. They are particularly bad this year. I've never found a way to stop them other than meticulously smearing them off every day. Funnily enough it's my climbing french beans that have become infested with them. This muggy weather has really encouraged a lot of pests and I don't see many ladybirds or their larvae to clean up. There's also a lot of beet leaf miner here in London.

[Penellype]

The ladybirds will eat the aphids, but may not make much of a difference if you have a large infestation. The difficulty is killing the aphids without killing the ladybirds. one thing I have tried with whitefly, which sort of worked, was spraying the worst affected leaves with water that had boiled potatoes (cooled obviously). The starch from the potatoes apparently dries out the soft bodies of the insects. I have no idea if it would kill ladybirds, which have a harder outer coating (exoskeleton). It was tricky to do - a normal sprayer is quickly clogged with potato so I ended up putting the water in a pop bottle and sloshing it onto the plants. It did seem to reduce what was a huge infestation of whitefly nymphs.

[Jungle Jane]

Soap is harmful to the beneficial insects,it’s good you’ve got ladybirds. Overwintered beans are a bit earlier,they can get some good growth before the black aphid appear. They could be started in pots.

[TrixC]

I have the same problem. I've heard that overwintering broad beans are less likely to be affected, but I've never had success with those because my soil is too heavy. And pinching out the tips doesn't seem practical when so much of the plant is affected.

I am even reluctant to use soap sprays as there are a lot of ladybirds on them - although sadly they don't seem to be making much of a dent in the aphid population. Does anyone know if the soap sprays are harmful to ladybirds and their larvae?

[MarkPelican]

The blackfly have moved off my broad beans (well actually I pulled them all up) onto the Dwarf French Beans and Courgettes. Blackfly seem particularly bad this year. They're on my tomatoes as well except they get trapped by the tomato tar and die without seeming to do much damage

[MelanieSW]

That's one of the reasons why I don't grow broad beans every year, it takes me while to recover from the horror...
I wash them off with the hose, and then spray with soapy water. But the blackfly keep coming back with a vengeance.

[Dorothyrouse]

I’ve pinched the tops off, sprayed them with water, squashed some ( yuk), and sprayed with garlic spray!

maybe I’ll try a soapy spray.

have also picked what are ready to eat!

[ameno]

Squash them.

Pinch out the tips. It's the soft new growth they love. Alternatively just keep blasting them off with water.

So people say, but my broadbeans are inundated with them, despite me going around and squashing all I can twice a week. Some plants are strangely untouched, but the ones that are infested are covering the entire top 6 inches of stem, and on the flower stalks, and some on the petals themselves, and on the developing pods (only the small ones, mind. The bigger ones must be too tough).

[Bren In Pots]

I use a mix of garlic and Encover washing up liquid mix plus pinching out the tops. Try adding something soapy it helps when you’re squishing them.

[peanut]

Pinch out the tips. It's the soft new growth they love. Alternatively just keep blasting them off with water.