Most controls are directed at the larval stages, with the most common being chemical drenches to infested soils. In addition to the many older materials that have been recommended for controlling fungus gnats, new chemicals are available. Many of these new material are insect growth regulators. Because these materials interfere with the development of the immature stages they don't have much activity on the adults. If a rapid reduction in adult activity is required, they will not be effective.
Biological control is another option that has had success in a number of Florida greenhouses.
Nematodes are becoming widely accepted as a valuable alternative to pesticides. Beneficial nematodes do not attack plants. The infective stages are applied to the soil using standard spray equipment or through the irrigation system. The infective stages are then able to find and kill the fungus gnat larvae. As with any biological control agent, the end user must check the product for quality.