BeneficialFungus gnat
Entomopathogenic nematode for fungus gnat
Steinernema feltiae · nematode
Against fungus gnat
The nematode swims through the film of water in wet compost to find the larvae, so it goes on as a drench and the compost must stay moist afterwards. It does not touch the adults; counts on sticky cards fall once the flies already in the pots have died off. Apply early or late in the day, out of direct sun. Sources differ on repeats: weekly (UNH), every 7–10 days (Arbico), or after 4 weeks (Dragonfli).
Rate250k–500k /m² of compost surface; about 5 million per 25 houseplants
TimingFrom potting or sticking; repeat weekly to every 10 days while larvae are found
Temperature10–30 °C
macro · entomopathogenic nematode on fungus gnat
The pestFungus gnatBradysia spp.Larvae chewing roots in wet mediaFull pest profile →Before you order
Drenched into moist media against larvae in the root zone. How it works, how to tell it has established and the supplier list are on the full Steinernema feltiae profile.
Release calculator
How many do I need?
Area and infestation level in; quantity, cost and a weekly schedule out. Open the calculator →
Other controls for fungus gnat
- Stratiolaelaps scimitusPredatory mite · 100–500 /m² of compost surface (Dragonfli: 100 preventive, 500 on a heavy infestation)
- Bacillus thuringiensis israelensisMicrobial insecticide · Label rate — Gnatrol home label 1–1.5 tsp per gallon of water as a soil drench, wetting the compost surface; Mosquito Bits sprinkled over the compost and watered in
- Rove beetlesWild predator · Nothing to release — the greenhouse species Dalotia coriaria is the one sold
- Dalotia coriariaPredatory rove beetle · 0.1–2 /sq ft (about 1–22 /m²); suppliers differ
- Macrocheles robustulusPredatory mite · 100–500 /m² per release, repeated once or twice