Fungus gnats in houseplants
The adults flying up when a pot is moved are the sign everyone notices; the damage is done by larvae in the top few centimetres of wet compost, feeding on fungi and roots. Letting the surface dry between waterings is often enough on its own. Where it persists, the nematode is watered in and finds the larvae itself — but only while the compost stays moist, so pick one approach per pot.
At a glance
- Damage
- Larvae chewing roots in wet media
- Type
- Root
- Settings
- Under glass, Garden, Indoors
- Threshold
- Larvae under a potato slice, or adults on a yellow card
- Release
- Steinernema feltiae
- Rate
- 5 million nematodes treats up to about 25 houseplants
How to confirm it
Press a slice of raw potato into the compost surface and lift it after one to two days: translucent, legless larvae with shiny black heads gather underneath.
Identification, lifecycle, degree days and every control option are on the full Fungus gnat profile. Not sure it is this pest? Answer four questions about the damage.
Work it out
How many do I need?
Carries Steinernema feltiae and houseplants through so nothing is re-entered. Open the calculator →