Allotments 4 All

Having convinced myself by searching on here that my broad beans may survive an attack of pea and bean weevil, I noticed today that some of the plants were covered in ants. What damage will they do and is there anything I can do to deter them?

they're waiting for the black fly to arrive........... ???

They may be farming blackfly, if any are present, but they may well be taking nectar from extra-floral nectaries under the leaves.

The ants are there to farm aphids and may even imposrt some so they can harvest their sugary output.  they will laso make nests under yor plants and these tunnels can leave the roots under the soil dry and starving as they are are no longer in ocntact with the soil and its nutrients.

Water your broad beans with a solution of 10 litres of water to one small bottle of essential oil of cloves avaialble from good paharmacies and health shops.   The ants can't bear the smell and will move away.  You could also use proprietary poisons and ant traps if yo'ure not organic.

They'll also attack any ladybirds or other feeders on aphids I believe. Dont they effectively "milk" the aphids to get them to produce more honeydew?

Nasty! I've always hated ants and now I have another reason!

Would grinding up cloves and scattering them on ground deter ants?

if you feed the ants on a sugar-rich diet they'll treat the aphids as a protein source.
apply syrup / jam to lower leaf joints. ;)
( I have tried this, it works)

Hello Alex.  I don't know but it must be worth a try.  You could also infuse some cloves in boling water and then pour the cooled brew around the plants.

my broad beans were covered with black ants n aphids last year  leaves ended up nearly all blacky/brown and destroyed though I did have some lovely beans

this year I have been watering each evening with left over washing up water  and spraying every other night with garlic water   so far (touch wood!!) they are looking pretty clear 

I have ants on my broad beans and as far as I can tell no or very few aphids. I've spent many hours watching them (sad I know) and noticed they seem to gravitate to the small dark spot which is on the furl of tissue just below the leaf nodes. This is not a blackfly as it's on every node in exactly the same place. The ants seem to be feeding from it. I cant find any info on this but have heard of other plants which have symbiotic relationships with ants- offering food or shelter and in return gain protection from the ants. I have a degree in zoology so although not an expert, I sort of know what I'm talking about.
Any body know anything about this?

It's an extra-floral nectary. That's a fancy way of saying it's a bit of the plant, not a flower, which oozes nectar.

Thanks for that, having done a bit of browsing I've found an article on the subject. It's a form of mutualism rather than symbiosis.

http://www.ingentaconnect.com/content/bsc/ele/2003/00000006/00000006/art00002

Are these nasties on the broad bean plants "black army" to avoid getting this my husband always says if you plant them really really early you don't get black army. is this info any help to any one.

                    we didn't grow broad beans this year, still had some in the freezer.               qahtan