Hi there guys! I’m new to “Tomato” Cough! Growing and this is my first post.
I have had a bad time with Fungus Gnats too. I’m sure they came in the compost bought from a local garden centre and exploded into life in the veg room, weakening plants and making it hard to take cuttings.
Thanks LolaGal I like the Idea of the Mosquito dunks crushed and sprinkled over the soil and watered in. If only I had heard of these and Gnatrol a few months ago.
I did a fair bit of research on FG’s and hope this helps you guys.
The adults live 7 to 10 days and lay their eggs on moist soil surface. Females lay up to 100 to 300 eggs in batches of 2 to 30 each in decaying organic matter. Eggs hatch in 4 to 6 days; larvae feed for 12 to 14 days. The pupa stage is about 5 to 6 days. 28/36 days from egg to dead.
Plant damage symptoms appear as unexpected wilting, low vigour, poor growth, leaves yellowing and defoliation.
They can be controlled by the Predatory mite, Hypoaspis miles. The H. miles, is a voracious predator of mites and insects that spend most part of their life cycle in the soil, including Gnat larvae and pupae of thrips. Once introduced, H. miles usually can reproduce and establish.
First, prevention should be your goal, and this is to avoid over watering, especially in high organic soils.
Adults are attracted to bright lights, mainly in the blue spectrum like PL’s and fluorescent,
If you are having problem with FG’s in a hydro set up? Then I would suggest looking elsewhere for any infestation. House plants or mothers if in compost, hydro and compost grow in the same room, or even areas in the garden which might be a breeding ground.
Fungus Gnats need a damp soil/compost medium to lay their eggs. It’s the hot, humid and bright condition attracting the adults to a hydro only set up. Using Mosquito dunks in a hydro set up is ineffective at best for killing Gnat larvae.
I managed to wipe out my infestation by covering my pots with clingfilm which can be lifted for watering, but stop the females from getting to the soil to lay their eggs, and thus break’s the life cycle. I also microwave any new compost before using it. This seems to have worked for me, not seem a gnat for a few weeks now... fingers crossed.
If... or when I get them again I’ll give the Gnatrol or Mosquito dunks ago.