Topic: Black fly on my broadbeans

[Strawberrygirl]

My broadbeans are covered in black flies. I have used a mild household detergent on my rosebuds for same but doesnt really do the trick. Does anyone have any good ideas that doesnt involve harsh chemicals. There are a few ants on them too, as well as ladybirds which i know is good, but not enough to eat them all!

[TISH]

I usually blast them off with the hose, in addition to the usual pinching off the top few inches of the plant.

[BarriedaleNick]

I think just about everyone suffers from blackfly on the broadies...
Couple of things..

Nipping the tops out - the tops are the most tender and generally where the fly starts off - niping the tops off helps to slow down the spread.
Soap mix - I would use a soap based spay as opposed to say a washing up based one.  It does work with a few sprays..
Hose em off - if you have access to a hose then you can blast em off - the plants can take it!
You could try neem oil - esp a neem oil/soap mix...  http://www.discoverneem.com/neem-spray.html..

BTW the ants are "farming" the ahphids for honeydew and actively move them around the plant and between plants!

[Strawberrygirl]

Thank you both for the advice. I shall get out my son's water blaster!

[antipodes]

I have never had broadies without blackfly!! I try to wash them off but usually give up...

[Ben Acre]

I pinch em off and put them on the Bird table.

[artichoke]

My allotment neighbour swears by water with crushed garlic in it. I'm going to try it tomorrow. Has anyone else tried it?

I don't mind nipping the tips off once a good collection of flowers are starting to produce beans below the tip, but too many of my tips are in fact flowers as well this year, possibly because of lack of watering (no water at this plot, and I draw the line at watering BBs with what I carry up).

[Digeroo]

1.  Grow a non susceptible variety like marsterpiee green long pod
2.  Make sure you get rid of every any you see, since they farm blackfly
3.  Freeze the beans for a few days before you sow them/

[Ben Acre]

Later beans wont have the sappy tips that autumn sown beans will have so autumn sown beans will be more susceptible to Aphids.

[Vinlander]

Make sure they are well supported then BLAST THEM with a fairly coarse spray - though you may have to wait until everyone else goes home before you will have enough pressure (this weather).

One key tip - if they have been on there for a while then they will be embedded in honeydew which will resist the hose.

Blast them lightly at least an hour before you blast them properly - this will let the water get into the honeydew and loosen it. In a really bad case you may need to spray a few times at half-hourly intervals.

NB. If the ladybirds have been doing their job you might find that 90% of the black gunk on the plants is a mixture of dead flies and honeydew...

Cheers.

[Jayb]

Later beans wont have the sappy tips that autumn sown beans will have so autumn sown beans will be more susceptible to Aphids.

I've always found it the opposite, later sown beans having the 'sappiest tips' and generally seem to be preferred by aphids.

[Robert_Brenchley]

I've always found it to be worse on later planted beans, but I thought that was because the blackfly take time to build up their numbers as the season progresses. Between blackfly and summer heat, I've never had much luck with later-planted beans, but the drought and the heat did for most of my early-planted ones this year.

[THE DOG]

Place a few lady bird hoeses in amongst the plants, they will feast on the BF.

An easy way is to cut off the bottom of a pop bottle then bury it in the ground sothe cut open end sticks out about 8 inch, then roll corrugated cardboard up and place in the bottles, perfect home for the perfect black fly preditor.

[chriscross1966]

Get rid of your local ant colonies by putting ant-poison baited traps around the beans .... jsut putting powder down won't do the job properly... the reason the infestations get bad is because the ants are farming the aphids and will defend them against ladybirds etc.... kill the ants and the predators will do their job...

[picman]

Find the ant nest and do for it....

[Fork]

I take a good long look at my BB's at very regular intervals...if I see ant movement I move in and search for the black aphids....if I find them they are squished with my fingers!

[Vinlander]

Place a few lady bird hoeses in amongst the plants, they will feast on the BF.

An easy way is to cut off the bottom of a pop bottle then bury it in the ground sothe cut open end sticks out about 8 inch, then roll corrugated cardboard up and place in the bottles, perfect home for the perfect black fly preditor.

Ladybird larvae are even better - just as hungry and don't fly off to 'greener(fly) pastures' - try to find medium sized ones - the biggest ones may be ready to stop eating and start pupating.

Cheers.

[Kea]

I'm about to spray mine with a garlic spray i bought on a visit to a orchard open day. It got rid of Raspberry beatle last year in one application. Can't remember what it's called it's at my allotment..where I should be if both my son's hadn't independently both stressed me out on the subject of career choices, announcing life changing change of plans both on the same day.
One says he thinks he's failed this year at uni what's he going to do!;and the other has now decided to do a degree in German having not been able to do German AS last year as the school didn't run it. He's going to do the As next year and find a way to do A2 in China during his gap year!!! :o :o ???