these sumbeaches have been a PIA since amending a heavy dose of soy meal into the soil pile---most say not to worry they don't harm your plant---that's B.S.---they feed on decaying organic matter and will kill clones---they are competing for the same food source as your myco colony---difference is they don't give anything back to benefit your plant
adult eradication treatments---fly strips will catch the adults as will the hanging "hot shot"---they also like to plunge into a mix of apple cider vinegar or beer and drown
larva eradication---since they nest in the top 1/2" of the soil---many peeps will apply approx 1/2" of clean sandbox sand---this makes it less than habitable for the adult females to lay their eggs because the sand drys out quickly and they prefer a moist environment to do their thang
cut to the chase---this is what i am doing to rid my room of these fuggers---vacume up the top 1/2" of soil from all pots---spray maybe even water in the top of the soil with a mix of h20 and h202 to kill any remaining larva---also spray this solution onto whatever the medium is for your clones (rockwool here)---hang fly paper and hot shots to catch any adults---vacume the room to pick up any juvenile stragglers running around not yet flying that jumped out of the nest---you can also catch them mid-air in the vacume as they are pretty slow---you can find them around the lights and buzzing your head cause they are attracted to co2 we exhale---repeat another vacume session and the h202 mix if you see the fly paper and hot shots increasing the numbers they are catching
if you water instead of spray the h202 mixture into the soil---its prolly a good idea to re-inoculate the myco colony as there seems to be a bit of discrepancy as to the h202 possibly not just killing good mycos but beneficials as well---better safe than sorry---the more the merrier
wish me luck---if i didn't kill the shit out of my entire crop---the gnats should be gone in due time and plants thriving soon enough