Fungus gnat on bedding plants
In propagation the larvae feed on the callus and first roots of plugs and cuttings, and can slow or stop rooting altogether. Sticky cards track the adults and potato slices the larvae; Colorado State gives 3–5 larvae per slice, but Clemson says no threshold is established for propagation, so the nematode goes on as a drench early in the crop, before counts build, because the larvae are hard to see when the damage starts.
At a glance
- Damage
- Larvae chewing roots in wet media
- Type
- Root
- Settings
- Under glass, Garden, Indoors
- Threshold
- 3–5 larvae per potato slice in propagation
- Release
- Steinernema feltiae
- Rate
- 250k–1 million /m² of bench as a drench
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 bedding plants through so nothing is re-entered. Open the calculator →