Fungus Gnat Control
Adult fungus gnats thrive in moist warm soils and grow mediums, they do not damage plants but are a seen as a nuisance in greenhouses and indoor grows. However, the fungus gnat larval, which look like small white caterpillars with a black head in the soil damage roots and stunt growth, particularly in seedlings and young plants. A wilting droopy plant may not indicate a lack of water, but rather root damage by fungus gnat. They are usually found in wet, over-watered soils or grow mediums.
What works best for Fungus Gnat control?...
Most of the fungus gnat’s life is spent in a developmental stage such as Larva or pupa in the soil, so the most effective control is to target these stages rather than attempting to control the short-lived flying adults. Adults can be trapped using homemade traps or pheromone lure/trap.
Nematodes such as Stenernema feltiae and predatory mite Hypoaspis miles are both predators that attack the fungus gnat larvae in the soil. Both predators are very popular with experienced growers as a preventative measure. Both because of their low cost and effectiveness. High infestations will require multiple releases.
For high infestations Stenernema feltiae, Hypoaspis miles (aka Stratiolaelaps scrimitis) and Dalotia coriaria (rove beetle) will co-exist and may all be released together.
Stenernema feltiae: Fungus gnat larvae, Root Aphids, Leaf Miners, Shore Flies, and Thrips.
Stratiolaelaps scimitus: Fungus Gnat Larvae, Thrips, Sciarid Flies, Shore Flies, Root Aphids, Springtails, Root Mealybugs and Poultry Mites.
Dalotia coriaria: Fungus Gnats, Shore Fly, Thrips, Springtails, and Root Aphids.