Field Identification
Slender dark flies that flicker around pots when disturbed; larvae live in potting mix and feed on fungi, decaying roots, and tender root hairs—often the hidden cause of poor establishment in overwatered seedlings.
Long legs, thread-like antennae, Y-shaped wing veins visible with a hand lens; larvae are translucent with a black head capsule. A yellow card at media level catches adults for monitoring population trends.
How to Deal With It
Organic Control Methods
Bacillus thuringiensis israelensis soil drench kills larvae where products are labeled; neem cake or soil drenches with neem can suppress larvae—avoid drowning roots chasing adults.
Steinernema feltiae nematodes, Stratiolaelaps miles (Hypoaspis) mites, and Dalotia coriaria beetles are standard augmentative controls in propagation.
Let the surface dry between irrigations; pasteurize or use consistent-quality mix; avoid green compost in cell trays; bottom water to keep surface drier.
Yellow sticky traps at rim height; potato slices on media surface lure larvae for monitoring counts.
Inspect bought-in plugs; screen house intakes; store bagged mix dry and sealed.
Let Nature Handle It
Natural Enemies
- Steinernema feltiae
- Stratiolaelaps scimitus
- Dalotia coriaria