Fungus gnats and control
Johnson3591@aol.com (Thu, 11 Dec 2003 06:29:06 PST)

Hi,

Fungus gnats are a problem sometimes. One thing I do is to avoid using peat
moss unless the seeds really want it (e.g., azalea seeds). Peat moss and
too-damp soil can lead to amazing numbers of fungus gnats.

I have found that insect bombs and foggers (that are marketed to clear up
fleas inside a home) take care of fungus gnat infestations, and I have not
observed any damage to seedlings (I suppose damage could happen).

A sure approach involves misting plants and soil surfaces to wetness with
pyrethrin or other low-toxicity (for humans) insecticide; this will kill the
larvae/eggs in the soil. You just need to be sure that the insecticide is safe
for your seedlings. If you don't treat the entire collection of seed pots and
nearby houseplants the fungus gnats can recolonize quickly.

One email friend recommended using fly strips (sticky paper), I have not
tried this approach. The goal is to trap all emerging adults before they can lay
eggs in the soil.

LINK: OSU Fungus Gnat Factsheet
http://ohioline.osu.edu/hyg-fact/2000/2114.html

Cordially,