Fungus gnats (Bradysia species) - also known as dark-winged fungus gnats, are small, mosquito-like insects often found in homes and offices, usually in the vicinity of houseplants. They are considered a nuisance when present in noticeable numbers, but the adults are harmless insects that do not bite. Fungus gnat larvae develop in the growing medium of houseplants and are considered minor pests of houseplants.
Adults are 1/8 inch long, delicate, black flies with long legs and antennae. There is a distinct "Y-shaped" pattern on the forewings. The larvae are wormlike and translucent, with a black head capsule, and live in the gorwing medium of houseplants.
Fungus gnats are small, delicate bodied flies that commonly develop in the growing medium of houseplants. Larvae of fungus gnats feed on algae, fungi and plant roots in growing medium. Adults do not bite or feed.
Fungus gnats can be controlled by allowing the growing medium to dry between watering. Some insecticides and biological control agents can be used to control fungus gnat larvae in growing media.
Fungus gnat larvae usually are located in the top 2 to 3 inches of the growing medium, depending on moisture level. They primarily feed on fungi, algae and decaying plant matter. However, the larvae will feed on plant roots and leaves resting on the growing medium surface. Larvae develop rapidly and are fully grown in two to three weeks. They then pupate in or on the growing medium.