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a guide to COCO and Fungus Gnats (little black flies)

habeeb

follow your heart
ICMag Donor
Veteran
^ interested in your method..

I was reading up on bti's.. it was saying the larvae eat it.. I wonder if there attracted to it in the first place.. like they put something in it to attract them.. and it seems you gave them a nice buffet for them then... haha. then I kinda also wonder, how the bti can reach the bottom of buckets for people who have sneaky ones.. as it wouldn't seem it couldn't get to the bottom if it is resting on the top surface???

also it was saying, don't apply to water that has copper ( nutes might have trace amount? ) and chlorine.. so anyone knows for future

also wonder if it does anything in way to off balance other bacteria in the media???
 

Chevy cHaze

Out Of Dankness Cometh Light
ICMag Donor
Veteran
^ interested in your method..

I was reading up on bti's.. it was saying the larvae eat it.. I wonder if there attracted to it in the first place.. like they put something in it to attract them.. and it seems you gave them a nice buffet for them then... haha. then I kinda also wonder, how the bti can reach the bottom of buckets for people who have sneaky ones.. as it wouldn't seem it couldn't get to the bottom if it is resting on the top surface???

also it was saying, don't apply to water that has copper ( nutes might have trace amount? ) and chlorine.. so anyone knows for future

also wonder if it does anything in way to off balance other bacteria in the media???

Hi Habeeb,
The BTI will multiply once in the soil/ coco.
You add it with you waterings and then it spreads throughout the pot by multiplying so it gets to the bottom no problem.

regarding the copper... Not sure about this, never heard anything that this would pose a problem.
But I used chem nutes from a rez, and I'm sure there a re ztraces of copper in there along with the mangan, boron etc...

I don't really know if the put anything in there to actually attract mosquitos to be honest ( would make sense eh ?)... but the fungus gnats were completely wiped out within a couple days. The flyers stuck to sticky traps and no new ones coming after them.
To prevent possible future infestations, I sealed my air inlets with a screen and put a layer of perlite on top of my pots.

all the best, take care,

cc
 

rgold1963

New member
While all of my coir experience is with large scale organic greenhouse tomato production, the solution I use should be the same for anyone growing on coir(or any medium for that matter) that has fungus gnat problems. The predatory mite Stratiolaelaps scimitus Womersley (formerly Hypoaspis) has provided me with excellent control for very low cost.
I apply them in the first week after transplant and never worry about fungus gnats for the entire crop. There is also the Rove beetle (Dalotia coriaria) or Atheta coriaria which also targets shore flies and works better in areas that have more standing water/algae.
I have had very good results using them with an NFT system.
Both of these are readily available and fairly low cost, chemical free solutions.
If anyone wants more info on either of them, feel free to send me a message.
 

svrn

New member
You can look for products containing bacillus thuringiensis israelensis like Neudomueck f.ex.
They sell those products to keep ponds and stuff mosquito-free and it works with those gnats as well.
The larvae of the gnats in the coco/soil eat it and then it dissolves their digestive system.
then get the adult flies with yellow stickies and break the cycle with a perlite top layer.that worked for me perfectly.

sounds really harsh, but it does the job efficiently and it's not affecting the buds, so you can use it even during last weeks of flower.

Mine were all gone after a couple days.

good luck &take care

cc

That's what I do and it works great.
 

azad

Buzkashi
Veteran
I encountered this problem, but it cleared up once I began using H+G roots excellorator. I've since switched to Great white with no problems or reinfestaion since. Try it your roots will thanks you for it.
Best vybz
 
T

thesloppy

It's slightly remarkable that the cheapest, most available (and highly effective) methods don't seem to get much play in these pest threads:

A simple hot water bath will kill most plant pests, without affecting your plants....provided the plants are small enough to get completely submerged. The two methods I see prescribed most are a 110 degree bath for 20 minutes, or 120 degrees for 5 minutes.

Similarly PURE, NON-DETERGENT (this is an important distinction, don't ignore) dish soap and vegetable oil has been proven extremely effective at killing all soft-bodied insects, and can be used as a dunk/bath, or a spray. 5 tablespoons of PURE, NON-DETERGENT dish soap, and 2 tablespoons of vegetable oil will give you a 2% insectidal soap mix. If that proves too hot for your plants/lights, then cut it in half for a 1% solution, which is less effective but gentler on your plants. Dunk containers in soapy water for a couple minutes to treat roots/medium and flush well until there's no more soapy residue coming from the runoff.
 

master shake

Active member
I had a battle with these bastards in my last grow/current mother plants. Finally got something that works great and isn't full of pesticides/chems - a wine trap!

Simply take some red wine (cider vinegar works too I read), pour into a shallow and wide dish, and stir in a little bit of dish soap. The wine and vinegar attract the gnats and when they land on the surface, they can't get out due to the surface tension of the water being broken from the soap. Place the dish under the canopy, and leave it for at least a week or 2, or for good since it seems like they always come back this time of year. Add a little water every couple days as it evaporates.

This works for fruit flies too, and I found out it works for fungus gnats too!

Vinegar-and-dishsoap.jpg
 

GodZson

Member
I had a battle with these bastards in my last grow/current mother plants. Finally got something that works great and isn't full of pesticides/chems - a wine trap!

Simply take some red wine (cider vinegar works too I read), pour into a shallow and wide dish, and stir in a little bit of dish soap. The wine and vinegar attract the gnats and when they land on the surface, they can't get out due to the surface tension of the water being broken from the soap. Place the dish under the canopy, and leave it for at least a week or 2, or for good since it seems like they always come back this time of year. Add a little water every couple days as it evaporates.

This works for fruit flies too, and I found out it works for fungus gnats too!

View Image

This is great.. Saw a few and put up yellow traps.. Trying this tomorrow.. Thank you for sharing
 

p0opstlnksal0t

Active member
Have any of you guys tried top dressing your coco pots with diatomaceous earth? I am planning on throwing my drip rings underneath the layer of DE. will this cause any issues?
 

eric2028

Well-known member
Veteran
I read somewhere that a spinosad drench works well. Anyone have experience with that?
 

Weezard

Hawaiian Inebriatti
Veteran
And a layer of dryer sheets on the soil surface will prevent infestation.
Have not had one fungus gnat for years now.
Dirt cheap, non-toxic, and very effective.
Kush cross.jpg
 

Chevy cHaze

Out Of Dankness Cometh Light
ICMag Donor
Veteran
I just had them back again...
Since Neudorff doesn't make the liquid BTI solution anymore I had to go with mosquito dunks. It seems to have worked, the last adults are getting sorted by the yellow sticky paper, but has anyone ever thought about if the toxins from the the dunks, GoGnats etc might be taken up by the plant ?
I have used BTI many times, but just thought about the fact that the effect is based on toxins after all, the Bacterae Thuringensis Israelensis toxins...
 

Jhhnn

Active member
Veteran
Gnatrol works well.

Indeed it does. It was developed to control gnats in greenhouses. I found complete eradication to be impossible in my organic soil grow but gnatrol wdg really whups their bug junkie asses at 1 tbsp/gal & enough solution to thoroughly wet the top inch of soil. Apply 3 times a week apart. It works best when I use it before I even see any flyers. I just mix it into ewc tea.

https://www.valent.com/professional/products/gnatrol/index.cfm
 
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