Little grey flies

[johninblackpool]

Hi Folks

Hope someone can help
( I have also posted this on Weeds Pests and Diseases )

Earlier this week i took the covers off my raised beds for the first time and within an hour my lettuce and spuds were covered in hundreds of little flies, they were dark grey, not sure if these are what you call blackfly.
I washed them away with water and recovered them again,
Today i took the covers off again and check to see if there were any more flies and all was clear but within an hour they were covered again

Any help greatly appreciated

ps. I have read that people use soapy water to keep flies off, do you think this will help

Cheers
John

[miffy]

Are they flea beatles? If so a good organic way to get shot of the little blighters is to cover a piece of card with black treacle, run your hand over your crop whilst holding card over it, the little beggers jump up and get stuck to the treacle.
Don't know if that is your problem but worth a try. Good luck, Miffy

[snohare]

Might be fungus gnats ? They love to be indoors, in the warmth and damp, chomping on seedlings with succulent leaves, giving them all sorts of 'orrible diseases.
I have been plagued with these on my seedlings on my windowsills this year, I think they came in as eggs with the potting soil. My guess is that they lay their eggs in humus. So I went online and researched, did what the YouTube videos said; I put sand over the damp soil in the pots, removed all sources of rotting/fruity vegetation (they love compost heaps !) and put up sticky flypaper. Fairly made a big difference, I only get the occasional one now lurking under the pots, and when the local house spiders get going that will be them sorted. ( I hope. I don't like protein supplements in my tea !)
Blackflies are much bigger and fatter than fungus gnats, don't jump about the same even in warm weather - they just sit in a large black, traffic jam mass on the growing tips, don't even move when the hand of doom comes down to squash them.
Soapy water as once used is now banned, even in organic circles, because of the chemical residues in soap. (Think about it - Fairy Liquid and its pals' ingredients are made in petrochemical refineries !) But you can get organic sprays based on Essential Fatty Acids, such as Growing Success' "Bug Killer", they are about as ecofriendly as you will ever get - work by the physical effects of sticky plant oils on the insects breathing spiracles I think.

[johninblackpool]

Thanks for the advice Miffy & Snohare

They seem to be very similar to the type i have in and around the compost bin and as this is very close to the beds i am wondering if they are migrating when i remove the covers
I have removed them again today and as usual within an hour they were full so i gave them a tokan spray with soapy water and it has done the trick
Any idea what type of fly they are if they are coming from the compost bin and will they cause any problem with the composting

Cheers
John

[andrewo]

They could be blackfly or fruit flies, the latter are often found in compost. Did you use your own compost to feed the soil before planting? They could have been in the soil and have come out because they have been uncovered.

[snohare]

If they are fruit flies then they will not harm the compost I don't think, but they are a sign it is too moist if I remember correctly. Don't quote me on that though !

[johninblackpool]

Cheers andrewo

This is the first time I have grown anything
I only started the compost bin at the same time i built the raised bed so the compost is still green at the moment
the MPC i bought was the large heavy bags from B&Q, all my veggies have come up great at the moment just keep getting the anoying flies,
soapy water seems to be doing the trick but after the rain they all come back
Hopefully the flies won't cause too much trouble to the Veggies
Any perminant remmidies would be great

Chees
John

[johninblackpool]

I Have just added a weeks worth of shredded news papers so hopefully that will dry it up a touch
Hopefully that will sort out the flies
Cheers
John