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Fungus gnat larvae control

RedtailForester

RedtailForester

For as long as I've been growing, I have never been able to control fungus gnat larvae. They adults are fairly easily controlled with sticky traps. I've been told baking soil can do the trick but as of yet, haven't tried it. Does anyone have an effective means for controlling larval gnats?
 
I've read just letting the soil get good and dry between watering a can help control them since they feed on the moist fungus in the soil and on roots
 
I grow indoors and I got fungus gnats. They came out every time I watered, so I just misted to soil with some ortho fruit and veggie insecticide. I know some don't like chems but it did the trick. I think they came in the house with my wife's dame aloe plant
 
I haven't found a perfect solution yet. I have been using a top layer of an inch or so of perlite over the soil to discourage egg laying, mosquito dunks if I get infested, sprinkled cinnamon, diatomaceous earth, and yellow stickies. I STILL have some though. ugh.
 
I use H202 on the top and bottom water when they become an issue, I also hang fly strips under a light source in the evening they seem to be attracted to the light, the potato slices are used to draw the maggots up(from what I read) so you can ID em and exterminate. Drying out the soil sends em into a hibernation like state, they will come back when the soil gets wet again just not as heavy.
 
The dunks/sticky traps will help control them...but they'll always be there. I added a little more peat to my soil and it seemed to help more than anything I tried. What type of soil are you using? The organic types I tested last year seemed to be the gnats favorites. Gonna check out your potato link and see what it says...
 
Have you tried using hydrogen peroxide along with your watering? Also, I haven't checked for your specific issue, but you might check out this site to see if they have something for that: http://www.buglogical.com

Ah, here's one from that site:

Steinernema Feltiae Nematodes (SF)​
Are the most effective against larval control of several fly species (sciaridae, phoridae, leaf miners, domestic fly and also of some moth larvae. They patrol the top 3" of the soil.​
•Target pests include:​
Fungus Gnat, Mushroom Flies, Fruit Flies, Flea Beetles, Saw Flies, Tachina Flies, Crane Flies, Shore Flies and fruit flies.​

Do a search on "fungus" on that site, and a handful of options come up.
 
For any house/office plants I have, I put about a half inch layer of plain old sand on top. When the larvae attempt to crawl up, the sharp sand particles rip them to bits. Basically the same concept as DE, but sand still works when it gets wet.

Also, I keep mosquito dunks in my water reserve in the greenhouse, and use AzaMax as a soil drenching from time to time.
 
I've had a ton of these damn gnats this year and they ended up killing quite a few seedlings and small plants. Sticky fly paper makes quick work of the flying adults, but the larva are the ones that do the damage.
Those little f**kers just eat all the roots right off the baby plants.

I've been including a healthy done of these two chemicals in the water when I water the plants for the last week or so. The gnats are still there, but the population has thinned quite a bit.


The H2O2 is there to kill larva and fungus, the SNS 209 is a natural repellent that the plants soak up. I think the thought is that the larva won't eat the roots of plants that have been drinking this stuff . So far so good as I haven't seen any new damage in the last week.

IMAG0895.jpg
 
leave a mosquito dunk in your watering can. you may get adults come in, but they don't do the damage, the larva do. the mosquitoes dunk normally fixes the larva nicely.
 
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