This bug has been reportedly found in the following regions:
Dewey, Arizona Fort Bragg, California De Land, Florida Gulf Gate Estates, Florida Mary Esther, Florida Vandalia, Illinois Columbia, Missouri St Joseph, Missouri Dayton, Nevada Spring, Texas Short Pump, Virginia
These things can be incredibly destructive; I grow rare & heirloom fragrant plants & watched helplessly while the larvae selectively slagged my most irreplaceable plants. I had applied predatory nematodes as a preventative ; since I did not lose everything, they may have helped. I applied a BT drench yesterday,& am applying a diatomaceous earth barrier today;then I will spray Neem oil everywhere,(& pray).
I was told predatory mites(Hypoaspis sp.??) were better than nematodes at fungus gnat control,& will try that too. Can anyone tell me how much diatomacous earth I need to mix into my potting soil to make it hostile to gnat larvae?? Not just as a barrier; I'd like to incorporate enough into the soil to permanently check any future invasions.