I had small black fly's. I used safers Insecticidal Soap. It will kill fly’s on contact. I also soaked the soil with it because the fly's liked to burry in it.

You must do this several times and wash the plant after a few hours.

This is good soap because it is not bad for plant at all. It is actually not poisonous to humans either, I just wouldn't want to smoke it.
harris7 Reviewed by harris7 on . little flies hey i have these little flies in and around the soil of my plants. I dont think there doing much damage becuae my friend says ive had them for a while but i just see a few leaves that look like there gettin eaten. mostly bottom leaves. I just dont want them eating my buds Rating: 5