You have fungus gnats if the tiny flies come to moisture. Fungus gnats feed on moist, organic material. They do not live on the plant itself. Most common places are in the soil or in dead leaves. Finding small black flying insects is a sign you have fungus gnats. however, there is no reason to panic, get rid of fungus gnats for good.
Natural solutions for fungus gnats control
1. Inspect plants thoroughly prior to purchase for signs of insect pests. Turn up soil carefully. Now, near the base of the plant look for the glossy, clear larvae. Reject any plant sending up flying gnats.
2. Fungus gnats do best in damp soils. Thus, be careful not to overwater, especially during winter months when plants use less. When potting, avoid water holding. Organic material such as peat moss that may encourage egg laying.
3. If pests are present, allow the soil to dry to a depth of one to two inches between waterings. This not only kills larvae and inhibits the development of eggs, it also makes the soil less attractive to egg-laying females.
4. Apply a glass material as a top dressing to significantly reduce fungus gnats infestation and populating.
5. Use yellow sticky traps. Placed horizontally at the soil surface, these will capture large numbers of egg-laying adults. The gnats are attracted to yellow.
6. Use a biological pesticide as Mosquito Bits that kills damaging larvae, yet is SAFE for fish, wildlife, humans and non-target species. It is the best because it contains no harmful residues.
7. Also, you should use beneficial nematodes to destroy the larvae stage. These will penetrate fungus gnat larvae and then release a bacterium that consumes the pest from the inside out. The long-lasting nematodes are safe for use around pets, plants, and your family.
8. Make your own spray. Combine peppermint, cinnamon and sesame oils. You would get a non-toxic spray that will get rid of fungus gnats and other insects that gather around plants.