Fungus gnats in my plugs?

[MeAmoPedro]

I have been fighting a fungus gnat problem of late. Keeping top of soil dry, added liquid killer and mesquito bits on top. Weird thing is the plants seem most effected soon after planting. Yellowing leaves, tip curl, cupping but as soon as they go to harvest they seem to recover well and do better. Yields and quality making a slow comeback.
Now I notice a bug inside our sealed incubater (aquarium upside down over a heat pad ( to approx 76 degrees inside). I put a sticky card in there to monitor. Put cuttings in grow plugs (RapidRoot) inside the incubater , 6 feet away from any affected plant. But a bug was in there so now I wonder can the larvae be in the plugs? Seems no other medium it could be coming from. Some want to water every day, saying plugs get too dried out if you don't and some say that is too much, that is getting the buggers going and thats why they look affected soon after planting. Not being over watered once they are planted, so I wonder CAN Fungus gnat larvae be in my plugs???

 

[Mono]

Larve could be in your plugs, yes.

If you grow in soil, just place an inch of perlite in the bottom of the pot, plant as usual, then an inch of perlite on top of the soil again. The adults will not be able to get through the perlite to the soil so can not lay eggs.

After around a month the problem will be completely erased.

I would recommend using a top dressing of perlite as a preventive measure afterwards. You can always reuse it