Fungus Gnats in Nepenthes: Systemic Insecticide Treatment

Small flies on Nepenthes soil are likely fungus gnats. Larvae feed on roots, weakening the plant. The solution is a systemic insecticide applied as a soil drench.

Treatment

1. Use imidacloprid (Bayer 3-in-1) or acephate (Orthene).
2. Mix per label; drench soil until runoff.
3. Repeat in 7–14 days per label instructions.

Why Systemics?

Contact sprays miss larvae in the soil. Systemics move into roots and are ingested by feeding larvae.

Prevention

• Allow top ½ inch of soil to dry between waterings.
• Use well-draining mix (orchid bark, perlite, sphagnum).
• Yellow sticky traps catch adults.

Full details in the Sarracenia Northwest insecticide podcast: YouTube Link.