Tiny black flies

My garden seems to be under siege from these tiny black flies. I've never seen this particular insect before. They don't cluster like aphids. They seem to be interested in the soil in my new seedlings, and don't appear to be causing any harm to the plants. But they may be having some negative effect on them.

I've sprayed them with d/w detergent & alcohol, then detergent and ammonia, diluted with water, and finally with Sevin spray. They seem to enjoy the shower. Most don't even leave, some fly up an inch or two, then quickly go back to whatever their business is.

Does anyone have any idea what is attracting them? I don't have manure in the soil mix, and the mixture is all "fresh," not reused. I don't see any mold, and the plants seem healthy and growing well, albeit slowly.

Any ideas???

Tiny black flies is a wide spectrum in the insect world LOL.
How tiny is tiny?
Any specific flying pattern to these flies?

It sounds like fungus gnats. They like the organic material in potting mixes. The lay eggs in the soil and the larvae feed off the decaying organic matter.

They can be a real problem in the house but outside they should have enough natural enemies to keep them under control.

That would be a good thing, right, their keeping down the fungus population? This is hot and humid FL, so we get lots of mold and fungi. I'll have to stop being so mean to them, and let them "do their thing." Beneficial flies? Is that an oxymoron??? LOL

They're really small, about the size of gnats, maybe even smaller. They're solid black, and just look and like miniature house flies. They land, and sit, crawl a few steps, sit. You can see them moving around on the dirt, they're kind of shiny. If you bump the container, or blow on them, or spray them, some of them fly up a few inches, then they settle back down and go back to whatever they were doing. I've never seen them fly away, and they aren't interested in me, so I don't think they bite, not people anyway.

Thanks for the info! I'll have to thank them tomorrow! : )

Judith I just discovered the same insects today.

poppysie your answer makes sense to me. I just discovered some and they seem to be in the potting medium which is mostly peat moss. I sprayed insecticidal soap but don't know if this is enough. Will they damage seedlings? Any preventive measures?

You can sprinkle Diatameceus Earth around on the soil and it will get rid of them. I bought my DE at Home Depot and it wasn't very expensive. It works wonders.

JesseK

I have the same in my grow room. (peat potting/seedlings) Driving me nuts!! I thought they may be white flies and used a spray made to kill white fly, and I hung yellow stickies up. No flies were killed by the spray and none on the stickie strip.

I'm assuming the eggs were in the soil that I bought.

Thanks for the chemical name JesseK. I'm going to have to go get some at Home Depot this weekend.