Fungus gnat biology
Fungus gnats are a large family (Mycetophiloidea) of flies ranging from about 2 – 6mm (depending on species) in lenght with a pointed abdomen.
The presence of these small flies are indicative of dampness, stagnant water and/or mold formations. Excessive condesation or a lack of ventilation benefits populations. The larvae and pupae require an organic damp decomposing medium to develop. Sources include overwatered plant pots, damp wood and drip trays from air-conditioning units.
Methods to control fungus gnats
ULV fumigation with non-residual pyrethroids only temporarily removes flies. The medium that allows breeding of fungus gnats should be removed. Rotting plant material, moldy wood and moisture associated with these should be eliminated using for example de-humidifiers.