fungus gnats - 5 weeks

Here's a pic after Day 3 of a recent hatch. If all these flies were larvae chompin' on the roots, I don't think there will be any roots in another hatch! I flipped the trap upside-down already. The majority are ground-level on the reflective surface. I have a fan blowing upwards at the plant, so the gnat tend to hang out on the ground. The bottom chamber has two clones, and is only protected by a light-trap, so you can see the gnats are already headed downstairs. Twice a day I spray the ground and base of container with Simple Green and wipe up all the gnats. If the next hatch in a couple weeks is 10X this size, I'm afraid the plant is history!

Ordered some gnatrol. Plan on using gnatrol until harvest.

Read online that hydrogen peroxide (diluted 20% strength) would kill eggs and larvae. Apparently not. Didn't work for me.

Any thoughts?

chuck estevez said:

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Cool. Thanks. I saw gnat nix online too. Similar to putting a layer of sand as topsoil. Will try it.

AfgooCBD said:

Cool. Thanks. I saw gnat nix online too. Similar to putting a layer of sand as topsoil. Will try it.

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if your not around it or pets, No pest strips will wipe them out

I should have done this 5 weeks ago, thanks Chuck! Added a layer of sand, then gravel. Will treat w/ gnatrol too, once it arrives. At least that will give time for the plant to dry out.

That pic is just one side of the trap. The other side looks the same. Might be a couple thousand gnats total. I'm afraid how much root damage there was, and if the plant can recover once I stop the cycle of the gnats.

Holy shit now I am not sweating the stray gnat I see floating around my room... thats a full blown infestation right there. That gnatrol is a good product and have no worries about its application since its organic. Good air circulation helps too, not sure if you habe a fan hitting them at all but might not be a bad idea

I had a pretty good out break myself. The only thing I have had luck with is Spinosad. I tried letting the soil dry out, mosquito dunks, neem oil........

I just mix it with my water and flood the pot. The flyers disappeared pretty fast.

i have had another bad infestation.
last crop got maybe 1.5 oz per plant or less.

tried using fungus gnat preditors from the start, didnt work
hot shot pest strips not working
yellow stickies work for catching flyers. place on soil and in fan current, and celing
tried gnatrol
tried sns 209
the combo of both of these in each watering is working pretty good

but i am hitting next crop with imidi because i cant afford any more bugs and i think i saw an aphid even with MET 52 in the soil.

fuckn soil bugs are my nemisis

wish there was an organic preventative that would kill all soil bugs and be reasonably priced. anyone have any suggestions, something that would take care of thrips, aphids, mites, springtails, fungus gnats all at once that can be added to a cycle.

ohh be sure you dont have any chlorine in your water when you water with gnatrol.

Thanks for the heads-up. Trying gnatrol right now.

I've swept up 3 days of piles of fliers on the ground under the fan that is blowing straight up. It's like they are seeking refuge from the wind under there. One squirt of Simple Green and wipe it clean. No more fliers. Definitely lighter pile today.

Are they gnats or aphids?

ficklejester said:

Are they gnats or aphids?

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Fungus gnats, I think. And there are thousands, from this last hatch. Starting to slow down though, the fliers. Maybe the damage is already done by the larvae though. Hope not.

The pic is the same on the other side of the card, and I've wiped up 3 days of piles like this on the floor of the cab, right under the small circular fan that blows upwards.

Gnats have long legs, aphids have short ones. I zoomed in on the pic, i definitely see some gnats. The adults are harmless. Their presence doesn't necessarily mean the roots are beyond repair, they feed off fungus and can thrive without access to roots. Glad drying is helping, plants look good. Clean your room well after harvest!

Also keep your temps down in low 70's. They like higher temperatures around 80 degrees.

Lower temps won't get rid of them but it will help alot

bayer tree and shrub . took care of my gnat infestion. I mixed a strong batch at 100ml to 5gal pail of water . dunked hydroton pots 3 times over the coarse of 5 days . also used some mixed at the same rate as a top layer spray . this shit is the bomb! you can dunk coco and soil pots but it would require a different mixing rate.

I get gnats on occasion. A few months ago when dealing with thrips, I bought some "EcoSMART Organic Garden Insect Killer" (<<link) at Home Depot (<<link) along with 3-4 other things. It contains rosemary and peppermint oils. When I watered my plants and saw gnats, I'd spray the soil. For the first month or two I thought it was just coincidence that I didn't see a gnat for a week or two. But, it's pretty clear now this stuff works.

When I see gnats (usually when I water) I spritz the soil and a couple spritz into the runoff saucer. Maybe when I begin watering and again when I'm done. Maybe just when I'm done. I don't know what it does, but I won't have gnats for a week or two. Seems like a low-cost, low-effort, low-chemical way to keep them in check.

EDIT: I don't recall if I ever sprayed leaves. I'd be careful, trying a couple leaves first. Stuff smells astringent.