Topic: Black fly on runner beans and broad beans

[Maidenheadtaff]

 :(

I saw load of ants on my broad beans a few weeks back and i asked one of the old boys at the allotment if they were doing an harm.He said not.
But i noticed on closer inspection black areas up the stem and underside of the leaves.There are loads of ladybirds eating them but not quick enough.They have killed one runner bean plant already and i think both broad beans.I only have a few of each planted.
The girl on the next plot to me said spray them with diluted washing up liquid which i did this evening.

Do you think i am going to be able to save the plants and can i protect the other plants,just planted broccoli today and i've been looking after them at home for months so really don't want to lose them.

Can't believe these blighters are eating my plants if they are blackfly.They are very very small but all in a mass
 

[Robert_Brenchley]

I get loads on my broadies every year, and I've never seen them do any visible harm, even when a weak (presumably) plant is completely covered. If they really are dying I'd suspect another cause.

[star]

Hi MHT,

If the blackfly are so thick on the plant......I had this one year. I got a tiny drop of vodka and an earbud and dabbed the blighters. The ants took exception to this and swarmed round to protect their 'cows'.

The vodka did for them as well! Just make sure to dab the bugs not the stems, not sure how the stems will cope with neat alcohol..............................ps dont let the OH know your using his tipple ;D ;D ;D ;D

[Robert_Brenchley]

Meths is cheaper and just as effective, but soft soap is even cheaper.

[BockingBill]

I have always found that by nipping off the broad bean plant tops when each plant has sufficient flowers (and eating the tops as greens) has always kept the little blighters at bay.

[PurpleHeather]

Ants do herd greenfly and take them to plants, then milk them. Similar to how we keep cattle.

Not too sure if they do the same with black fly.

I know a lot of people do not want to harm ants but they are such a hardy species. Exterminating them from your food growing area is unlikely to put them into the the endangered category.

Nippon do a gel. You put out a few spots of it on a jar lid each night, the ants take the sweet stuff back to their nests and it makes the whole nest go to sleep. Permanently. It seems this stuff does no harm to the good bugs just the ants. The process takes up to a week.

[Old bird]

One very old gardener told me many years ago to cut a few branches of Elder flower/berry bush and stick them in with the broad beans and that will/should get rid of them.

It worked a couple of times for me and then a third time it wasn't as successful - but if you can get a few small branches then it is worth a try!  I hate blackfly as they make everything so yucky!

Good luck with it though!

Old Bird

 ;D

[tim]

Squidging is messy but terminal!

[kimbobill]

Just run the stems between thumb and the index and middle fingers and wipe them off

[Pumper]

Just run the stems between thumb and the index and middle fingers and wipe them off

YUKYUKYUKYUK

My answer = pick the tops off, and then the tried and trusted Systemic Bug Gun.
No, I ain't organic  ;D

[Drive-by abuser]

as others, nip the tops off.............sorted

[nordog]

as others, nip the tops off.............sorted

Thanks to all your tips. I have tried thumb & fore finger plus Fairy Liquid in my 10ltr pressure pump (that I normally use for washing my Mountain Bike in the winter) and lobing the tops off. Had some beans for Sunday dinner just right, so some thing most be working right. :)

[chriscross1966]

My two-pronged attack seems to have worked so far on my beans...

I've got ants farming blackfly BTW...

Basically in the evening last thing on warm days I spray infestations with a desert-spoon of cooking oil in a pint of warm water, add washing-up liquid or soft-soap until the oil is dissolved....

Get ant-bait trap and leave near bottom of infested plant.  The spray gets the bugs there now, the bait stations are killing off the ant colonies, any new blackfly that turn up are having to run a gauntlet of ladybirds and hoverflies.....

Kill the ants and most of the problem goes away....

chrisc