Fly plague after laying sod

[JohnnyB60]

I removed a tree and turned up a 100sf area to install sod. Within a week I had an outbreak of small flies. I think they are Fungus Gnats from my research on line.

I’ve tried insecticide for flying insects and after 3 cans I ended up with dry eye. I also applied a granular lawn insecticide on the lawn itself and cut back on the water, only to have twice as many flies or Gnats and my new sod is turning yellow.

I lived here for 18 years and never had flies like this before only a few common house flies now and again. Right now the infestation is so bad that I have ten sticky fly strips hanging from my patio ceiling and they are covered with the little buggers. I hate have these things hanging all over and its getting worst.

I know they are coming from the sod because that’s the only thing that changed besides removing the Apple tree. What can I do?

[applestar]

My advice would be to stop spraying/applying insecticide.
Natural order -- where there is a surplus of pests, predators will move in to eat them. BUT if you keep spraying broad spectrum insecticide, you'll just kill off the predators, especially since pests are typically more resistant to pesticides because they have adapted to them.

If they ARE fungus gnats, you could have tried spreading mosquito dunk pellets which contain bacteria that infect gnat larvae in the soil, but I'm not sure if your soil will support the bacteria now.


Ammonium sulfate acidifies the soil... which is more hospitable to fungi, which fungus gnats live on.... I don't know... That doesn't sound like the right direction to go?

[JohnnyB60]

Thanks applestar,
I only used the granular insecticide once. I was going to do a second application but the dogs were rolling around and rubbing their backs in it so I quit. I also have a desert tortoise that normally doesn’t like the lawn but will eat a little off the edges.

Anyway I do have some mosquito dunks that I put into my outside drains. They are little donuts, but is there another form that they come in or do I break them up?

[JohnnyB60]

I was looking around for more information on Fungus gnats and was lead right back to a thread on this site in 1009 suggesting cinnamon, so I ordered some and I'm going to give it a try. I'm pretty sure they are Fungus gnats, but I added this photo of some I caught on one of many fly strips just in case I may be wrong.