Black fly on Runner Beans

[mintymow]

What should I use on black fly that are collecting on my runner beans. Does a solution of washing up liquid work (I've heard that recommended) if so how strong should it be. I have used a proprietary bug spray but they don't seem to mind it too much and anyway it should not be used too often. Thanks for any advice.

[daisydee]

Don't know about the washing up liquid but apparently planting marigolds with the beans is supposed to keep them away.

[Bromsgrove]

One method I have used which does work, is to use a garden spray, at full pressure, or a hose and drench with with water. Repeated a few times this clears them by washing them off!

[madmaggot]

Please don't use pesticides as these will also kill their natural preditors including the birds that eat the bugs; making your problem worse in the long run.

[Whoever]

Yes, it's that time of year again and my runner beans are starting to become infested too. I spray with diluted washing up liquid, using two or three GOOD squirts into any kind of empty household cleaner misting-type sprayer and topping up with water. Give it a good shake before spraying. The problem with using a priprietary bug spray is that it could harm any blue tits, other birds, or ladybirds who feed on the blackfly. Early infestations can often be killed by simply squashing gentle with your fingers if you're not squeamish. Don't forget to check the underside of the leaves as well as the stems.

[rabbitygirl]

Diluted washing up liquid or water with garlic is often used against blackfly and aphids. According to Monty Don, these bugs are the first wave. If you kill them now you drive away their natural predators such as lacewings and ladybirds, which may not return to your garden to feed from their favoured pests. Not only that but the dilutions mentioned above may also harm these friendly and useful insects.

While he doesn't propose leaving all the blackfly and aphids to suck the life out of your veg, he has a point and it is all down to balance.

I usually use a well worn toothbrush, or baby's one, and gently brush many of the bugs from the plant.

I'm not that dedicated where I could banish them in their entirety anyway!