[Dans]

I'm still quite a novice veg grower. Tried some lettuce in the polytunnel this year, a friend sowed it while she was sitting for us and did it very thickly. When I went to thin it I noticed a lot of black flies. I was quite ruthless in my thinning but a week later the whole veg bed is teeming with these little flies, mostly crawling rather than flying. I have lettuce, peas, carrots, onion and garlic in that bed. I have lettuce in other beds in the polytunnel but they are unaffected, they are also different soils though.

Any ideas what they are? I can try and take a picture if it helps but they are quite small. They don't seem to be causing damage to the plants but I have noticed white round specks on some of the leaves from lettuce from this bed.

Dans

[PK]

I'm assuming you would recognise black fly (aphids) so my guess is that they are sciarid flies, sometimes known as fungus gants, which are common in compost. I don't think they do much damage on established plants.

[Dans]

Yes! That sounds right. They look a bit like gnats but we weren't getting bitten and that bed had an explosion of mushrooms when we made it. Thank you!

Dans

p.s.