What does black fly look like?

[janekt]

Could someone please descibe black fly. My nasturtium have what look like little black beetles or aphid like insects. Are they likely move on to my veg and will they cause harm?

I also have aphids and other little bugs on my lettuce that I've just been washing off, they don't seem to be doing any harm am I doing the right thing by just leaving them?

Jane

[Vegmonkey]

If they get anywhere near your beans they will cause devastation if left. I list them fourth in my list of my most hated pests, behind slugs, snails and top of the pile, cats!

Try googling blackfly and clicking image search....there should be a pic on there

[rustylady]

Blackfly are aphids, Jane. Look like little black beetly things crowded together all around the stems of your precious plants. They suck the sap and transmit disease, so don't just leave them alone. You can either squash them, squirt them off with a jet of water, or use insecticide spray - your choice!

[sewer rat]

Hi Janekt
Your nasturtiums definitely sound as if they have been plagued by blackfly. However, many people grow nasturtiums as sacrificial plants as blackfly quite often will infest them instead of any beans. So in a way it's really 1 - 0 to you.

[janekt]

Just had a look at this:

http://www.bbc.co.uk/gardening/advic...ack_bean_aphid

Looks just like them and I also have a lot of ants about too

They are right next to my dwarf french beans and I suppose not far from everything else. Should I leave the nasturtium there as a deterent or pull it out?

Please help I hate creepy crawlies!!!

[Two_Sheds]

wait till your nasturtium is absolutely infested and then rip up the lot, blackfly as well, and compost it (extra protein!)

[sewer rat]

The ants will farm the aphids, so when you do as Two Sheds suggests, the ants problem should see a serious decline

[janekt]

What about soapy water or is that an old wives tale?

[terrier]

Hi janekt, soapy water works to a point as does squirting them off with a jet of water but it depends on how bad the infestation is. You really do need to get rid of them even if it means trimming off the infected parts of the plants. It's one of natures nasties I'm afraid.

[janekt]

I'm just concerned that if I mess with them they'll just find something else to infest

[terrier]

The first thing I learnt about when I started growing flowers was APHIDS. There's no escape. Just a fact of life. You win the battle but the war goes on.

[Alice]

I'm just concerned that if I mess with them they'll just find something else to infest

You're right. Just call the nasturtiums sacrificial plants. While the blackfly is happy there, it's nowhere else. If it gets too bad pull the whole lot out and burn it. Many of us grow nasturtiums as sacrificials to keep the blackfly off other things.