What is Fungus Gnat?

Fungus gnats, also known as sciarid flies, are small flying insects that belong to the family Sciaridae. These pests are commonly found in moist environments, such as indoor plants, greenhouses, and gardens. Fungus gnats are often considered a nuisance due to their ability to reproduce rapidly and infest plants, causing damage to the roots and leaves.

Life Cycle of Fungus Gnat

The life cycle of a fungus gnat consists of four stages: egg, larva, pupa, and adult. The adult female lays her eggs in the soil or on decaying organic matter, such as plant debris or fungi. The eggs hatch into larvae, which are small, worm-like creatures that feed on organic matter and plant roots. The larvae go through several molts before entering the pupal stage, where they transform into adults. The adult fungus gnats emerge from the pupae and begin the cycle again by laying eggs.

Identification of Fungus Gnat

Identifying fungus gnats can be relatively easy due to their distinctive appearance. Adult fungus gnats are small, delicate insects with long legs and wings. They are usually black or dark gray in color and have a slender body. The larvae, on the other hand, are translucent and worm-like, with a black head capsule. These larvae can often be found in the soil or near decaying organic matter.

Behavior and Habits of Fungus Gnat

Fungus gnats are attracted to moist environments and are commonly found in areas with high humidity. They are most active during the spring and summer months when the temperature and humidity levels are favorable for their development. These pests are weak fliers and are often seen hovering around plants or flying in a zigzag pattern. Fungus gnats are also known to be attracted to light sources, which can be used as a method of trapping and monitoring their presence.

Damage Caused by Fungus Gnat

Fungus gnats can cause significant damage to plants, especially in large infestations. The larvae feed on the roots of plants, which can lead to stunted growth, wilting, and even death. In addition to root damage, the larvae can also feed on the stems and leaves of plants, causing further harm. The presence of fungus gnats can also attract other pests, such as spider mites and aphids, which can further damage the plants.

Prevention and Control of Fungus Gnat

Preventing and controlling fungus gnats can be challenging but not impossible. Here are some effective methods:

1. Proper watering: Overwatering can create a favorable environment for fungus gnats. It is important to water plants only when necessary and allow the soil to dry out between waterings.

2. Soil drench: Applying a soil drench with insecticidal soap or neem oil can help kill the larvae and prevent further infestation.

3. Sticky traps: Placing yellow sticky traps near plants can help capture adult fungus gnats and reduce their population.

4. Biological control: Introducing beneficial insects, such as predatory mites or nematodes, can help control the population of fungus gnats by feeding on the larvae.

5. Removing affected plants: If a plant is heavily infested with fungus gnats, it may be necessary to remove and dispose of the plant to prevent the spread of the pests.


In conclusion, fungus gnats are small flying insects that can cause damage to plants by feeding on their roots and leaves. Identifying and controlling these pests is essential to prevent further infestation and protect the health of plants. By following proper watering practices, using soil drench treatments, employing sticky traps, introducing beneficial insects, and removing heavily infested plants, it is possible to effectively manage fungus gnat populations and maintain healthy plant growth.