Fungus Gnats on Spider Plants: Identification & Control

Fungus Gnat Basics

Adults are nuisances; larvae in soil can damage roots, especially on young plants. Life cycle: eggs hatch in 4 days, larvae feed 2 weeks, pupate 3–4 days.

Control Strategies

• Isolate infested plants.
• Dry top 2–3 inches of soil between waterings. Empty drainage trays.
• Repot severely infested plants in fresh, sterile mix.
• Yellow sticky traps (cut small, stake in soil) catch adults.
• Bti (Bacillus thuringiensis israelensis) – apply as Gnatrol or Mosquito Bits every 5 days.
• Vinegar traps: Jars with vinegar + dish soap, holes in lid.
• Potato slices on soil surface attract larvae—check after 4 hours.
• Pyrethrin soil drench as last resort—apply outdoors, wait a day before bringing in.

Combine methods for best results.