This came from Texas AMUTable 1. An inventory of considerations and options which can be incorporated into a fungus gnat management program (from Cole 1985, Drees 1992 and Lindquist 1994).
--------------------------------------------------------------------------------
Non-chemical (cultural) methods:
Potting media containing compost less than 6 months old may be more attractive to fungus gnats than that containing "older" compost. However, some of the less attractive potting mixes may result in increased plant injury because larvae may feed on plant roots rather than on fungi in the media.
Avoid over-watering. Over watering contributes to fungal and fungus gnat larval development. Conversely, too little watering may aggravate fungus gnat larval injury to plants, because larvae may enter the plant stems in search of moisture.
Avoid introducing infestations into a treated planting by bringing in infested plants.
Avoid providing habitats for fungus gnat development underneath benches, etc. If possible, separate plant propagation areas from the main plant production areas (by using separate houses or screening between these areas), since propagation areas generally have more severe fungus gnat problems.
Practice good sanitation: remove debris and old plant material from in and around greenhouses.
Potting media treatments (for larvae):
Biological control:
Parasitic nematodes (Exhibit¨, BioSys¨, Guardian nematodes, Scanmask , Ecomask , etc.*,**) and others (S. feltiae, Heterorhabditis spp.)
Predatory mites (Hypoaspis spp.) (1 to 50 per container)
Microbial insecticides:
Bacillus thuringiensis var. israelensis (Gnatrol¨*,**)
Insect growth regulators:
azadirachtin (Azatin¨ EC*,**)
fenoxycarb (Precision¨*)
kinoprene (Enstar¨*,**)
Nerve-active insecticides
chlorpyrifos (DuraGuard *,**)(surface spray)
diazinon (PT¨ 265 KnoxáOut¨ 2FM*,**)(surface spray)
oxamyl (Oxamyl 10G*,**)
Foliar treatments (for adults):
chlorpyrifos (PT¨ 1325 ME Duraguard *,**)
cyfluthrin (Decathlon¨)
diazonon (PT-265¨ KnoxOut¨ 2FM*,**)
horticultural oil (SunSpray¨*)
oxamyl (Vydate¨*) - no longer being produced for ornamental market
pyrethrins (Pyrenone¨ Crop Spray)
resmethrin (Resmethrin EC*,**)
Fogs and fumigants (for adults):
diazinon (PT-1500R¨ KnoxáOut¨*,**)
nicotine (Nicotine Smoke Generator*)
resmethrin (Resmethrin EC 26*,**)
--------------------------------------------------------------------------------
* approved for greenhouse use; ** approved for interiorscape use
