Applying Neem oil to kill off fungus gnats?

[OldPathBluSky]

Hello
I have been having a small infestation of fungus gnats lately and it seems they are multiplying quickly. The plants I have that are in jeopardy are the young seedlings and clones, as I understand the larvae of fungus gnats feed off of roots and are attracted to organic matter. My question is how should I apply the neem oil to the soil? I usually spray neem oil as a foilar spray to get rid of odium and mites, so what is the best what to apply the neem oil to the plants' growing medium? The plants that are being effected are all in 3/4 liter and 1 liter pots right now, the growing medium is Edna's Best organic soil, and the fertilizer being used is Age Old Organic Grow. Will applying the neem oil effect the ph level?

OldPath

 

[billb]

i use gnatrol. works great

 

[OldPathBluSky]

Can you buy that at home depot?

 

[Pirate138]

Use 1/2 a mosquito dunk for 1 gallon of water.

 

[Rosy Cheeks]

The best thing against the Fungus Gnat larvae is not neem oil, but Bacillus Thuringiensis, a soil-dwelling bacteria which attacks the larvae and prevents them from feeding.
It can be found in a number of specialized pesticides, such as this one from Hydrogarden:



The larvae also need lots of moisture to survive, which is why you should let the medium dry out (as much as possible) between waterings. This will kill off a large percentage of the larvae population, and hopefully the BT takes care of the rest.
Combine this with regular Pyrethrine treatments on your plants, and the gnats should be history.

 

[stinkyattic]

Neem won't kill them outright.
Go around your room and hunt for all the places where there is standing water or permanently-wet media. Typical trouble spots are floor drains, puddles under a leaky table or fittings, catch-trays under pots (put the pots UP over the tray, not IN it, using bricks or something), and especially under grow bags. If I were to use grow bags, I'd put them on a grid like the ones used on factory floors in fishing boats, or anything that can take a lot of moisture and dry very fast.

 

[GET MO]

I used Nematode S. Felteia, killed um off in 2 days with no return, its a nematode that eats the larvae from the inside out, you shoulda seen the adults go crazy when I applyd it!!

 

[OldPathBluSky]

Thank you for all the replies, much appreciated :smile:

OldPath

 

[billb]

gnatrol, you can get at www.wormsway.com or most hydro stores online. wormsway you'll get in about 2 days after order. thats regular shipping they are fast. but i would definelty get some. its some good stuff

 

[Jayoharejee]

i had this problem at the beginning of my grow and noticed if you use a layer of sand over the top of the soil it'll sufficate the larvae living in your soil. Worked well. Get a spray to kill off whats flying around.

 

[billb]

very true, sand is great i forgot to add that. but in my book it is a must

 

[OldPathBluSky]

Sand sounds like it would do the job. I went to the hydro store to day to try and find some gnat off, or gnatrol, but I couldn't find nada. So the hydro guy recommended SM-90... do you guys know anything about this? He said not to spray it on the leaves at all, and to just dip the soil into it when it's diluted in water. It's supposed to be good for roots anyway, any info it appreciated :smile: Oh, and is it safe to use this up to harvest time? The hydro guys said yeah, but he was on the phone so I wanted to get another opinion.

edit: Nevermind, I found some on the net here it is:

"A product called SM-90 is my personal favorite for natural pest control. It is citrus based and works well against mites, thrips, and fungus gnats. Mix according to directions and spray 80 percent under the leaves and 20 percent on top. Repeat every 3 days, up to 3 times. You can use this up to the week before harvest, but make sure to wash any residue off the plants with heavy misting.

You can also use SM-90 each time you water your plants, to get the insect pests living in your soil. Unfortunately, if you are growing organically, it will also kill some of your beneficials. If you are using hydroponics, keeping SM-90 in your nutrient reservoir at 2-3 ml/gallon keeps fungus gnats at bay."

So I'm gong to try this out and see if it works and I might also put sand on the top of my soil containers.


OldPath

 

[Kenny Lingus]

and water mostly from the bottom will leave the surface cust dry and rid any pupa of their moisture...

 

[HeadyPete]

never used sm90 but gnatrol, mosquito dunks etc are all the same, Bti bacteria and they all work very well.

Nematodes are also excellent, but pricey for an easily solved problem like fgnats.

 

[s13sr20det]

did you try the sticky whitefly strips? they're only like 2.50 at wal mart

good luck