Identification
Small, dark gnats (2–4 mm) flying around pots and scurrying across the surface of the substrate. The adults are a nuisance, but the real damage is done by their larvae in the soil, feeding on the roots and the base of the stems of young plants. A constantly moist, humus-rich substrate favours their development — the classic result of overwatering houseplants.
Treatment
Above all, reducing watering and letting the top layer of substrate dry out (the larvae die in dry soil). Yellow sticky traps for the adults, covering the surface with sand or perlite, and, if needed, insect-parasitic nematodes or preparations targeting the larvae.
Sources
- Houseplants — plant protection
