Tiny black flies on surface of compost mulch

[lalilooParticipant]

Hello. I purchased lots (and lots!) of mushroom compost last autumn, some of which has been spread on my allotment beds. I’ve noticed today that all of the beds with the compost layer are covered in swarms of tiny (3-4mm) black flies, crawling all over the surface. When disturbed they fly/hop a little way but drop back down to the surface again. Are they something to worry about, as I’m preparing to plant lots of my veg seedlings over the next couple of weeks? If so, any advice on what I can do about them, please?
many thanks, Nic

[DerekParticipant]

I have what I suspect are the smae type of fly on the top of a compost bin. Seen them before and just assumed they were there as it was warmer than elsewhere. I have never worried about it or done anything about them.

[JanGreenParticipant]

Hi, I would be very interested to know if they do any damage too!
I had them last year on top of my black plastic compost bins which contained horse manure and the garden waste.
These are situated near my raspberry canes and I did see a few tiny worms (maggots?) in some of the raspberries and wondered if the tiny flies were responsible!! 🙁
Jan

[charlesModerator]

I have these flies sometimes and they have never harmed anything, I think they are agents of decomposition.

[lalilooParticipant]

Thanks everyone – I shall leave the little critters in peace to get on with whatever it is that they are doing (having a massive compost party/festival I suspect, from how many there are!)

[Author]

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