Fungal Gnats

[herblover]

Hello everyone newbie here, currently 16 days into flower of my first grow and while feeding tonight, noticed bugs in the soil, my mate told me that they are fungal gnat larvae, could anyone tell me how bad this is/could be for my crop and how to nuke the little buggers?! PS will post pics for feedback soon

Thanks

 

[Danksta408]

That is the exact same problem I'm dealing with right now...........About 6 days into flowering, I noticed them in my soil too...........Little black gnats..........I've been using Organicide and spraying the top layer of soil with it........It seems to work cause everyday, there's hundreds of dead ones on the floor of my cab...........Also, I spray the floor of my cab just enough to leave it wet so that it kills them if they hop out of the pots..........If there's a better way to deal with them, I'm all ears

 

[THRIPS AHOY!]

i cant remember completly what we used to do for the fungus gnats but you want to use a spray for the flying ones like ambush or end all or something and sprinkle sevin powder on the dirt.if u check in the infirmary im sure you will get better info.

 

[Danksta408]

i cant remember completly what we used to do for the fungus gnats but you want to use a spray for the flying ones like ambush or end all or something and sprinkle sevin powder on the dirt.

Would it be okay to use a spray on the plant itself when it's flowering??.......Wouldn't that cause mold and alter the taste and smell of your buds??

 

[Hammerhead]

Just get some of those no pest strips they work great for gnats.

 

[dongle69]

Beneficial Nematodes.

 

[luvtogrow]

Cover soil completely with a layer of dry perlite. Keep top layer of soil dry as possible for a while. That will kill all the larvae and prevent the adults from laying eggs. Diatomaceous earth works very well as the larvae slice up on the stuff trying to get thru it. They will diminish yield slightly. So- get the strips up to kill some adults and cover the top layer of soil and grow that huge bud! Have never had a fungus gnat since buying my soil at an indoor location. I thought they were waiting outside my growroom my first few grows until I realized I was buying them in the soil. Fortunately, they are not as bad as they look, but no good to smoke if stuck in your bud.

 

[Dr Dog]

Cover soil completely with a layer of dry perlite. Keep top layer of soil dry as possible for a while. That will kill all the larvae and prevent the adults from laying eggs. Diatomaceous earth works very well as the larvae slice up on the stuff trying to get thru it. They will diminish yield slightly. So- get the strips up to kill some adults and cover the top layer of soil and grow that huge bud! Have never had a fungus gnat since buying my soil at an indoor location. I thought they were waiting outside my growroom my first few grows until I realized I was buying them in the soil. Fortunately, they are not as bad as they look, but no good to smoke if stuck in your bud.

I agree with the layer of perlite

Keeps them from having babies, they only live for about a month, and as an adult only a week, the problem is that the female can lay hundreds of eggs in that time, take away the breeding ground, you take away the gnats, no pesticides required.

They only really cause issues to young plants, as plants get older they are a nuisance not a problem

 

[vindiesel]

i just noticed a few kants in new mom tent. i have 6 new cuttings i keep moist. i dont see them around 4 potted baby cheese though. just buzzing around. i see like 1 or 2 every time i open tent. i squish whatever ones land. i dont see them on plants/cuttings. no knats in flower tent...

 

[herblover]

ok thanks everyone, food for thought, ill try the perlite/ dry soil option and no pest strips. cheers to all repliers, no doubt be back with more questions soon enough! time to get chinese eyed

 

[illuminatus]

Mosquito dunks work as well!
-illuminatus

 

[poppasmirf]

hope im not too late to jump in..but if your room is not too big, than i would suggest using blue sticky cards/traps. its takes time but eventually as the larvae become adults they fly into the blue cards and cant reproduce..keeping your soil more dry will help as well. and you wont need to spray or apply chems...YAY

 

[MickTheBrag]

use sand as a mulch about 1 inch layer on all your pots and the gnats wont be able to lay their eggs. i reckon the sand method is more effective than the perlite way just my opinion.

 

[Danksta408]

Well after applying perilite to the top layer of soil and watering with hydrogen peroxide (30ml/gallon), I haven't seen them flying around my lights or on my cab walls..........Small, dead gnats are accumulating on cab floor........So they are being exterminated........I also did a light misting with RO'd water........Thank you for the knowledge everyone

 

[luvtogrow]

Hi Mick. Disagree with you about the sand being more effective. Perhaps more deleterious to the gnats than perlite (not much), but perlite is more grow friendly and won't choke off gas exchange at the soil enterface. I've only used perlite in this manner and am just repeating what i've read about sand hindering oxygen exchange. Anybody? I've also used Gnatrol many years ago and would not use it again. Perlite worked better.

 

[Dr Dog]

With sand I would be more concerned with causing a top layer of mud when I watered.

Thus causing the plant to be surrounded by wet all the time around the stalk. This is asking for trouble IMO.

 

[MickTheBrag]

With sand I would be more concerned with causing a top layer of mud when I watered.

Thus causing the plant to be surrounded by wet all the time around the stalk. This is asking for trouble IMO.

ive tried both methods and the sand is best. and theres no way corse grit sand will turn to mud when water is added.

 

[luvtogrow]

Did some searching and found quite a few gardeners that use sand to rid the gnats. A common recommendation is 1/4"-1/2" thick. Thin because as I mentioned, compacting nature of sand, reduces quantity of oxygen exchange to the roots. So, if perlite works (and it does), i'd recommend trying perlite and using sand as a last resort. I have no first hand experience with using sand as top dressing, but remember years ago what I've stated and reread again this am. Probably not a big issue but want it all out there. Must be some botanists out there that know.

 

[Ganja baba]

Hello everyone newbie here, currently 16 days into flower of my first grow and while feeding tonight, noticed bugs in the soil, my mate told me that they are fungal gnat larvae, could anyone tell me how bad this is/could be for my crop and how to nuke the little buggers?! PS will post pics for feedback soon

Thanks

to querentee to get rid of them , use a nematode drench , it will kill all the eggs and last upto 6 weeks by that time all are gone works every time for me ... yo get them from the sites that sell preditors ...

yo can also use gnat off , but they come back most of the time and cost alot more , cause you need to keep adding it ...

sorry didnt look through the thread , so some one else prob said the same thing , hopw you get rid of um , honest this seems to be the best full proof way ,
gb

 

[Greenskies00]

Use Gnatrol and Yellow Sticky Traps.