Tiny Soil Bugs: Fungus Gnat Larvae Controlled by Drying

Grace has basil, cilantro, and mystery variegated plant. Cilantro/basil had scale (treated). All three soils release tiny dark, narrow bugs (1/32-1/16") when watered. No flying adults. Insecticidal soap and peroxide failed.

Identification and Cause

Likely juvenile fungus gnats. Color/size match. They feed on rotting roots from overwatering.

Solution

Cut water back—keep plants drier.

Alcohol drench: Water/spray with alcohol—kills on contact. Peroxide bleaches and damages plant tissue; avoid.

Never leave standing water in saucers.

Dry conditions break the cycle. Bugs disappear as roots recover.