Infestation of dwarf beans (pic)

[dan1979]

I pulled this one up when I saw the state of it, there's a few on some of the other plants but I sprayed some stuff and wiped them off.

Are these just standard blackfly? Why would they all congregate on this one plant?

The photo doesn't do it justice as to how covered it was:

[Capsid]

Oh yes! That is blackfly with a vengeance! They congregate because only a few start the colony off, then they lay live young which themselves are pregnant and the numbers increase exponentially.

[TinyT]

Wow! .....................

[Alice]

That's a good crop of blackfly. They're very partial to the bean tips. You have to keep a good eye out for them and deal with the problem straight away. Hope the rest of your beans are OK.

[dan1979]

Fortunately the others were fine apart from a few here and there, the important thing is there's plenty heading for the plate

[Two_Sheds]

Yes, they stay on one plant because the nymphs don't have wings. You need to nip this problem in the bud though, because they will breed superfast and spread to your other plants.

I have found Calendula (pot/English marigold) or nasturtium to be good sacrificial plants for blackfly.