Fungus Gnat

Natural Habitat

Damp, humid environments, often associated with potting soil, decaying organic matter, and overwatered plants. Commonly found indoors near houseplants.

Diet & Feeding

Larvae feed on fungi, decaying organic matter, and plant roots (especially tender root hairs of seedlings and young plants). Adults do not feed significantly and primarily focus on reproduction.

Behavior Patterns

Adult fungus gnats are weak, erratic fliers and are typically seen hovering near the soil surface of houseplants or crawling on windows. They are most active in low light conditions. The larval stage, which lives in the soil, is the damaging stage, feeding on roots and organic matter. Their life cycle is relatively short, often 3-4 weeks, allowing for rapid population growth in favorable conditions.

Risks & Benefits

Risks: Larvae can damage plant roots, leading to stunted growth, wilting, or even death of plants, particularly seedlings and young plants. They are primarily a nuisance pest indoors. Benefits: In natural ecosystems, they play a role in decomposition and nutrient cycling by feeding on fungi and decaying organic matter. They are generally not harmful to humans, though large populations can be annoying.

Identified on: 10/2/2025