Fungus gnats are small, "mosquito-like," gray-black, flies of the Sciaridae fly family often noticed around house plants and windows. Found throughout the United States, most species inhabit fungi or dead plant materials, but sometimes young maggots injure plants by feeding on roots. This occurs particularly if the maggots become very numerous and thus limit their food supply.
Host Plants and DamageFungus gnats are general feeders. They attack a wide range of ornamental and vegetable plants. Some species can be serious pests in mushroom houses. The maggot or larvae is the damaging state. However, the adult flies are usually noticed before larval damage to the plant is apparent. When maggots become numerous they strip the roots resulting in loss of plant vigor and yellowing and wilting of the leaves.



