fungus gnats

Discussion in 'Garden Pest Management and Identification' started by luckimoose, Jan 26, 2006.

  1. luckimoose

    luckimoose Member

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    I've have had trouble over the last year ridding my house plants of fungus gnats- particularly my aloe plant. I'm hesitant to use too many pesticides b/c I have pets. Any other ideas?
    Thanks!
     
  2. LPN

    LPN Well-Known Member 10 Years

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    Every year about this time the same thing happens to me too. Dry soil discourages them but you have to water plants too. So I've used double sided sticky insect strips. They land on the strip and that's it, ... stuck!
    Cheers.
     
  3. Megami

    Megami Active Member 10 Years

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    Fungus gnats suck! The best way to get rid of them without using any pesticides is to just let the soil dry out for a couple days to kill the larvae, and put a layer of sand over top of the dirt in your plant pots (this can be problematic if you have a ton of plants, but works well if you only have a few) - this prevents the adults from laying eggs in the soil as they only lay eggs in organic mater.
     
  4. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

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    Another effective trap is an ashtray filled with water and a few drops of dish washing liquid. The adults drown when they land on the surface to drink. Use an ashtray that is the same color as that of the sticky yellow strips if available. I have one that color and another that is forest green. The yellow one always ends up trapping more than the other.
     
  5. luckimoose

    luckimoose Member

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    Cool- thanks for the suggestions!
     
  6. Corine

    Corine Member

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    Anyone knows how to get rid of fungus gnat when growing hydroponics? Drying the soil becomes quite impossible.
     
  7. jimmyq

    jimmyq Well-Known Member 10 Years

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    perhaps a few drops of pyrethrin based liquid insecticide in the reservoir? of course make sure there is no soap base to the product. technically there is nothing registered for use in canada for such a purpose. make certain to not release your reservoir contents in to the water system for at least 48 hours after applying the pyrethrin. dont use synthetic pyrethroids as they have a much longer half life. pyrethrina is VERY toxic to fish. Natural pyrethrins supposedly break down in something like 6 to 12 hours in sunlight (UV) exposure.
     
  8. Corine

    Corine Member

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    thanks Jimmy!
    I'll research that further
     
  9. Equilibrium

    Equilibrium Active Member

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    You might want to consider a biological control. Fungus gnat larvae feed on roots. Not good. I have been successful using Hypoaspis mites but have also had good success with Bacillus thuringiensis sub. israelensis. They're both readily available these days and affordable also.

    Other than that, a nice Drosera binata or a Pinguicula spp. might help.
     
  10. Corine

    Corine Member

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    Hi Equilibrium!
    I have been looking into using Hypoaspis mites. however I am wondering if they themselves become a problem if they proliferate.
    In the case of Bt...In what form does the bacterum comes? where to get it? should I put some in the reservoir or with each individual plants?
    Thank you!
     
  11. Equilibrium

    Equilibrium Active Member

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    Last edited by a moderator: Feb 11, 2006
  12. jimmyq

    jimmyq Well-Known Member 10 Years

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    BTi is sold as a mosquito killer for ponds in Canada, it is not registered for use in hydroponics or any other situation other than what is on the label.
     
  13. Equilibrium

    Equilibrium Active Member

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    To the best of my knowledge, I know of no situations in which Hypoaspis mites have become a cause for concern. They are target specific.
     
  14. Dave L

    Dave L Member

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    Old post but information is for sharing!

    BTI is the way to go in soiless or soil applications. It is marketed in a variety of forms from Knock-out-gnats and Gnatrol to simple mosqiuto dunks. The later are much cheaper and you can crush up and make your own solutions. Adding BTI to the soiless medium may or may not help. The common mistake when using BTI is timing. You really need to watch hatch cycles for BTI to be effective. Also, use in conjunction with the yellow sticky traps to catch adults...no adults..no larvae!

    In soil, this can be tricky. The best advice starts BEFORE you even plant. Watch where you get your mix. Depot and Lowes have lovingly provided me with bags that were INFESTED with gnats, so look for signs. When planting, mix up you BTI or add to you wetting agent (water) when mixing/preparing soil. This will give you a head start along the journey. Let mix dry out well between waterings to discourage breeding.
    Keep foreign plant matter out of the house, including open fruits/veggies etc.
    Avoid tracking in grass and leaves from outside...yada yada.

    DE or Diatomaceous Earth can also be used in soil apps to damage larvae, but care must be taken when using (silica hazard).
     
  15. chirita

    chirita Active Member

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    Regarding Bti in mosquito dunks and using them for fungas gnats: I would like to try these but am wondering what kind of a concentration to use for indoor plants. Can you add too much or does it matter. It was mentioned that timing is an issue- could you water it in weekly for maybe 6 weeks and hopefully hit the right timing somewhere along the way?
     
  16. chemicalx

    chemicalx Active Member

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    I added beneficial nematodes to a houseplant (dracaena) that had a bad gnat problem, and I haven't seen a single gnat since. It's been a few months now. I also applied them to my backyard, because it's a mixture that works for a whole list of baddies, including cutworms, which decimated my bean rows last summer.
     

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