Is there a natural way to kill fungus nat larvae

Discussion in 'Growing Organic Marijuana' started by BeZtoken, Nov 22, 2011.

  1. So I have a rediculous amount of fungus nats. It was just brought to my attention that the larvae eat on roots. I have the sticky traps but that don't nearly get them all.

    Is there a all natural organic way to get rid of the problem thru waterings?
    BTW my plants are 30 days into flower if it makes a difference.

    Thanks, BeZ...V

  2. yes get the safer brand all natural spray from grow store and spray top soil good and spray leaves indoor is best when using pure coco you can still use your organic nutrients BUT you wont have bugs soil is a thing of the past I would never bring soil indoors but thats just me
  3. I fuckin hate those things. Try letting your soil dry out longer between waterings, I know the gnats and larvae love moisture and cant survive without it. It should help cut down on how many youve got, but I dont think itll completely get rid of them.
  4. You and me both brother. I used some not so ready EWC mixed with peat for my current class of cuttings. I was putting the worm bin in winter storage under the house, and i swapped out the castings for fresh compost. After a few days I lifted the plastic dome to check on them, and found many dozens of fungus gnats. I felt like that guy on the movie the green mile, lol. Here is how i treated them.

    First i put up a sticky trap, then I sprayed to soil surface with a pyrethrum spray, left an hour or two then roughed up the soil surface and sprayed again. Roughing up the soil I spotted lots of little wiggly white lines (gnat larva). I left the dome off to dry out the soil, and pointed a fan at the plants. When the plants needed water I used neem/karanja oil like i use in sprays but as a drench. All this took 3 days and it seems the gnats are history. The plants did suffer a little and lost some leaves. Now I am trying to return some biology to their soil, and new growth has started and looks healthy.

    In my flower box it is not uncommon to see an occassional gnat, but the same compost that seems to have gnats also has gnat preditors. At least that is my theory, because they never amount to any real threat, and I don't treat for them at all.......MIW
  5. I had a problem with soil gnats about a year ago when I was growing in this disgusting old warehouse, It used to be a maintenance barn for a trolley system in the city (before cars haha). Anyways the place was flithy and no matter how I tried to clean it I kept finding gnats and mites both EVERYWHERE!!

    eventually after trying everything "all natural" and "organic" in a bottle that every grow store guru / hydro shop hoho could hawk me. Well eventually I learned that nothing in a plastic bottle is going to help this problem.

    I refer now to LDz post on organic soil and pests:

    My solution was to make something called a "slurry"

    In my slurry I basically went on a scavenging hunt on my bike to find critical ingredients, what I couldn't scavenge I ended up buying the essential oils of any of the plants I could find in a co-op(yes, buying essential oils is expensive).

    I added mostly capsaicin (capsaicin is the "hot" in peppers)
    ABOUT CAPSAICIN(which i stole from wiki)Capsaicin and several related compounds are called capsaicinoids and are produced as a secondary metabolite by chili peppers, probably as deterrents against certain herbivores and fungi.

    in addition to the capsaicin which i found in extract form in a organic co-op I also added
    some of the root balls from past grows (yes marijuana root balls, and I'm not really sure why I put these in or if it actually did anything, but it felt right and I think it worked)

    so basically I simmered all of these ingredients up in a soup pot on my stove....the results of which were pretty scary. the entire room and several adjacent rooms were nearly unbearable to enter because of the capsaicin, my eyes were burning and tearing just nearing the slurry on the stove.

    so after a few hours of simmering I went ahead and strained the mix using some of my gfs nylons (gotta get them when they aren't looking or they'll freak!) after straining I put some into a foliar sprayer and then put the rest into my girls!

    Looking back I probably should have saved what I strained for either a repeat trial, or to use as a top dressing to ward against the damn gnats/mites but either way the capsaicin definitely made a much larger impact that the "safer" products and the various neem "oils" / "sprays" / "meal"

    Don't get me wrong I love neem meal/seed/cake whatever and I think it is a great preventative for pests, however I just do not see the stopping power when using it that I see when the gnats encounter the capsaicin! i'd say its very similar to using pyretheins sp**?

    I really hope you get your pest issue sorted out BeZtoken! Goodluck!

    • Informative Informative x 1
  6. you can use try to control them biologically.

    Bacillus thuringiensis (had to look up the spelling lol) is a bacteria that specifically infects gnats, blackflies, and mosquitos. Gnatrol is the popular product that MJ growers use that contains B. thuringiensis. in two applications you should see a ginormous reduction in their population.

    Beauveria bassiana is also another product i like to use. B. bassiana is a parasitic fungi that attaches itself to soft bodied insects and eventually kills them. B. bassiana affects but isnt limited to aphids, spider mites, thrips, and fungus gnats. The product I use that contains this fungi is called BotaniGuard.

    happy killing! :smoke:
  7. This is what I use, works well too. The bacteria in a product called mosquito dunks feeds off the larvae. Fight nature with nature
  8. happy killing indeed osu buck eyes.

    I do it by hand, and I also have dishes with powdered sugar and non-scented soap, they fly right into it's disgusting (a bowl left for several weeks may accumulate hundreds)

    But I'm glad they're that stupid. I also just recieved an order of hot pepper seeds, so I'm starting on a journey down that path. I got two really hot types and two cooking types. i also got some cinerarifolium mum and wormwood seeds, perennials.

    and I water with a stinging nettle FPE. (well as much as it ferments with these 40-50's temps. stuff is dank.
  9. #9 LumperDawgz2, Nov 23, 2011
    Last edited by a moderator: Nov 23, 2011
    Spinosad - produced from a fermented bacteria. You want to get the undiluted product like Captain Jack's Deadbug Brew to allow you to mix to the strength that you want to apply.

    This bacteria very effective against a wide range of insects. Our vet prescribes an oral version (Comfortis) for fleas and ticks. 100% effective.


  10. Hey LD, our vet prescribed it for my Catahoula earlier this year, but I was scared by some of it's side effects. I'm still using the Revolution, as we have major ear mite issues down here and the spinosad is ineffective in treating them. BTW, if you wonder why I just don't use the ear drops, then you've never tried putting them in a catahoula pit's ears. BTTT, have you noticed any lethargy or anything unusual after giving the comfortis?
  11. LD and everyone,

    I can't believe no one has mentioned the neem cake in this thread!

    If you want to kill the fungus gnat larvae, pickup some neem or karanja cake from

    Mix 1-2 cups of neem/karanja cake in water and bubble it approx. 24-36 hours so it fully dissolves.

    Water your plants.

    Problem solved.

    I had a bad outbreak at one point a while back and this completely took care of it.
  12. making a tea using that much will kill a lot of your soil biology, the better thing to do is just make a Protozoa dominant AACT, Protozoa eat fungus larvae nats and other larvae/negative things in the soil, plus you will still have some bacteria and fungus as well in the AACT, i believe you have to brew the tea for 48-72 hours to make a good Protozoa dominant AACT.
  13. I didn't notice any negative side effects, but didn't look at it under the microscope afterwards. It completely took care of it in 1 application.
  14. it will depend on how much neem oil is left over in the neem cake and how long you brew the tea and how much goes into the soil, i just know that neem oil and neem is not very good for the soil biology that benefit cannabis the most, so i would only use the neem cake in my original soil mix and then let it "cook" since it would allow time for the neem cake to do its thing and help as a preventative measure to fungus nat larvae and break down and allow the microbiology to adjust and flourish, instead of pouring it in part way through the grow and possibly making the plant more susceptible to other illness due to decreased soil biology that work in unison with the plant when growing organically. If you live in an area thats bad for fungus nats use it as a preventative measure. Also use cedar mulch because certain bugs HATE cedar and will stay away from your plants and Cedar is used in some insecticides.
  15. I did use it in the soil mix as well. I still think that if you have a bad outbreak this could be a viable solution. If you're concerned about damaging the soil biology, you could follow it up with an ACT application I suppose, or topdress and water in some EWC after the application.
  16. If you have a bad outbreak just make a Protozoa dominant organic tea (AACT) and water the plants, after watering and let sit for 30 minutes COMPLETELY cover the soil surface in Medical Grade Diatonomous Earth (dont know if thats how its spelled) and anywhere the bugs cant enter the container and the next time you water re-apply the DE because water will render it useless, if the first application worked (which it should) most bug problems should be gone (unless its some form of mite). This way wont effect your soil biology, if this fails, then id use the Neem Cake Tea as a last resort just because the soil biology is whats most important in organic growing and really your feeding/creating a soil biology more so then the plant itself, since the microbiology is what breaks down everything into plant usable form.
  17. Do you have any information/data to support this claim? As I stated, I noticed no ill effects on my plants within the days following the application.

    I avoid using the DE because the powder requires you to wear a mask, though it does work as well.

    What sorts of protozoa are you attempting to grow to eat the fungus gnat larvae? Is it species specific? Will any compost source work or do you need an inoculant?
  18. <shakes head>

  19. No it will not. Pure conjecture on your part. The specific Terpenes and Terpenoids in both neem and karanja seeds are only effective against fungi classed as saprophytes - it has no effect on Protozoa, Nematodes, Endo/Ecto mycorrhizae strains and in particular these agents have absolutely no effect on Bacteria which explains why adding neem meal to a worm bin will maximize Bacteria colonies = increased worm colonies (C.A. Edwards, R. Sherman)

    The biopesticide compounds in work as antifeedants primarily along with limiting the ability to reproduce. Their function as a biofungicide is far more complicated and beyond the original question by the OP.

  20. This is not an effective way to control fungus gnat larvae nor any other insect larvae, unless you happen to specialize in growing out the largest protozoa in the world, foraminifera, which can grow to 6 cm but that is not likely as they are sea dwellers. It is actually the other way around. Protozoa are a food source for many types of larvae as insect larvae are much larger than most protozoa and last I checked protozoa don't eat by chewing or ravaging with sharp teeth. [of course maybe if it works it is for some other reason]

    I don't blame you for making this error as some 'experts' have made the same assertion and have even confused larvae with rotifers.

    The most sensible suggestions I've seen in the thread are spinosad and Bacillus thuringiensis.

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