Fungus gnats

Discussion in 'Citrus' started by gwenn, Nov 12, 2006.

  1. StarLoc

    StarLoc Active Member

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    Yesterday i was laughing at the idea of cinamon on plants, i thought it was silly!...(Unles you were cooking them)

    I have been terrorised by millions of fungus gnats for some time, due to growing mushrooms in `grow it yourself boxes` as its nice and warm under the growlights

    The boxes of mushrooms regularly get filled with them on the cardboard lids, in the same room i have chillies, strawberrys, rhubarb and some citrus, the pots are were filled with them and air has had quite a few fungus gnats as well

    10 hours ago, i sprinkled the cinamon lightly on all the pots, and in the mushroom boxes, not all over just here and there

    Now NO FUNGUS GNATS! , well maybe one here and there flying past, there were hundreds, i dont know where they are, but they have gone!, theres a few sitting on the lids of the mushrooms, like they have been neem oiled, just still and refusing to move, but still alive, 99.9% have gone
     
  2. The Hollyberry Lady

    The Hollyberry Lady New Member

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    Hello!

    I told you!

    I know where they are - under the cinnamon - dead!
    I am surprised you didn't need a heavier sprinkling for that big of an infestation though - wow!
     
  3. Millet

    Millet Well-Known Member 10 Years

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    As I posted yesterday, I went out to the greenhouse and sprinkled powdered cinnamon on the Pinion Pine tray that was infested with fungus gnats. As Hollyberry claimed, the adult (flying) form of the fungus gnat quickly left the tray. Whether, cinnamon provides any control of the larva stage in the soil I cannot say. - Millet
     
  4. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

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    It would not matter. The life cycle will have been broken if the adults are repelled by the cinnamon.

    This is encouraging news. I wonder if cinnamon has any effect on the soil chemistry that may affect plant growth. (e.g. by altering soil pH.) Would it work over the longterm?
     
  5. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

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    Regarding my concern over the possibility of cinnamon affecting soil chemistry, I'd like to propose an experiment. How about strategically placing small amounts of the substance in shallow dishes amongst plants in the problem area instead of applying directly onto the soil? Perhaps that's enough to act as a repellent. Could someone try this out on previously untreated plants and report back?
     
  6. Millet

    Millet Well-Known Member 10 Years

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    Adjacent to the Pinion Pine seedling tray, is a tray of small root suckers taken from the base of an apple tree. I have the suckers growing on to obtain larger size, so I can bud/graft the apple variety Honeycrisp onto them. The fungus gnats don't seem bothered at all, they are still on the apple tray The two trays are almost touching. I'll give it a week and see if the cinnamon in close proximity bothers them. I never have a fungus grant problem in my container citrus trees, as they are all planted in CHC. I have never seen a fungus gnat in CHC. - Millet
     
  7. Junglekeeper

    Junglekeeper Esteemed Contributor 10 Years

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    Thanks, Millet. I look forward to your followup report.

    I found a document which, while not related to fungus gnats but to onion flies, may explain why cinnamon works as a deterrent. Source: Success with a SARE farmer grant: The science of fighting flies.
    On a related note, the following is a document which concerns Cinnamite (cinnamaldehyde), a pesticide derived from cinnamon: Dashing Pests with Cinnamon. It contains a potential warning but unfortunately no explanation is given.
     
  8. Millet

    Millet Well-Known Member 10 Years

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    Upon checking the Pinion Pine cinnamon treated seedling tray this morning, I notice that the fungus gnats were back. Further they never left the adjacent apple tray. - Millet
     
  9. The Hollyberry Lady

    The Hollyberry Lady New Member

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    Hello!

    When you have that big of an infestation, it's going to take more than one light sprinkling! My gnats are all gone - but I re-sprinkle every week - two weeks. You must kill the ones in the air too - I use a spray bottle filled with water and dish soap.
     
  10. StarLoc

    StarLoc Active Member

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    Mine have come back a bit, but nothing like they were, i presume eggs are hatching and it takes time to kill adults as they need to touch it?

    All plants i treated , just the compost, but on one chille plant i got it on the leaves of one of a batch of 30 cayene pepper chillie plants, all growing fine yesterday, i seperated it and watched with interest as i thought it may be hard on the leaves,i got rid of excess, but it could be seen as dust on the leaves,the one paprika chilie with it on the leaves has wilted all teh contaminated leaves, the one leaf still ok, has none on it

    Calamondins , i sprinked a few leaves on a small one, no effect on the calamonin leaves YET...
     
  11. MickiS

    MickiS Active Member

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    Hi. Well I brought in a flowering maple that I had outside and it was waterlogged and 'gnatty" lol sooo I tried the cinnamon on the soil. I was quite liberal with it so we shall see what happens. I quite like the plant but had gnats before that I couldn't get rid of. It is in isolation for a few weeks. I will let you know if the cinnamon does the trick. I am hopeful!
    MickiS
     
  12. roachslayer

    roachslayer Member

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    hmmm. I have CHC, and fungus gnats. :(

    Cinnamon seems to do almost nothing. Repelled a few, maybe. Killed them, definately not.
     
  13. roachslayer

    roachslayer Member

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    Here are some appropriate questions on this topic.

    1)
    Anyone know if this is safe on Citrus? BTi, (Bacillus thuringiensis subspecies israelensis)

    Often found in mosquito dunks, which in theory would be disolved and then use the water to water the plant, kil the larvae (works on other plants but if it harms citrus, obviously no good). There is also something called Gnatrol.

    2)
    Or is this safe for citrus?: Steinernema feltiae (ScanMask, NemaShield, Nemasys or Entonem) (Beneficial Neamatodes)

    http://www.learn2grow.com/problemsolvers/insectsanimals/insectsbeneficial/beneficialnematodes.aspx

    http://www.growquest.com/fungus_gnat 1&2.htm
     
  14. Ray from PA

    Ray from PA Active Member

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    Good thread.

    I bought a few bags of Miracle-Gro soil from Wal-Mart for my terrarium and got a terrible fungus gnat infestation along with yellow mold (thanks Wal-mart), something that never happened with the M-G soil from Lowes. Anyway, I had to completely empty the terrarium, but not before the fungus gnats moved into the chc I have the citrus planted in since the terrarium is in the same room. It's not a bad infestation like in the terrarium, but they're definitely in there, although it may be because there's peat moss mixed in. I put the Venus flytrap in the room and it seems to really be doing the job, although the larvae is still probably in the soil. No matter, I'll just completely replace the chc when I repot, minus the peat since I soak the pot anyway.
     
  15. MickiS

    MickiS Active Member

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    Hi. Well it has been a long time but I can report with enthusiasm that I have been able to eliminate and control fungus gnats with cinnamon. My flowering maple has now spent a couple of summers outside and is again in the house.
     
  16. Millet

    Millet Well-Known Member 10 Years

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    Personally, I think Cinnamon is absolutely worthless as a control for fungus gnats. However, if your tree is growing in a medium of 4:1 CHC/peat moss, or even 3:1 CHC/peat moss you should be able to kill gnats quite easily just by submerging the tree's container in a large bucked of water over night. Flooding of citrus roots does not even begin to cause any root problems at all, until at least after 48 straight hours. I have many times submerged my 4:1 CHC citrus over night. This should drown all the gnats. - Millet (1,152-)
     
  17. Ray from PA

    Ray from PA Active Member

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    I have submerged my pot completely to see if this eliminates the infestation. I'll let everyone know what happens.
     
  18. Ray from PA

    Ray from PA Active Member

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    It looks like that did the trick. I left it completely submerged for about 16 hours, took it out and removed the alum. foil from the top (for preventing the chc from floating away) and saw dead little wingless fungus gnats everywhere.

    Normally when I soak the container in fert. solution it's submerged to just below the soil line and they all come to the top to escape death, so after submerging it completely I let it dry out a little and then brought the water to just below the top of the soil. Even after an hour of sitting in the bucket there was zero activity, so it looks like they all died.

    Thanks for the idea Millet.
     
  19. roachslayer

    roachslayer Member

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    Yeah, this is a great idea. I'm seeing the same thing, tens of thousands of dead little punks. Only problem I see now is, there are some that survived and living on the surface tension of the water. Not sure yet how to be sure they do NOT get back into the container as I raise it out of the soak bin.

    Here is some insight so far with my process:

    TIP 1 - Metal Screen:
    I used a galvanized metal screen to keep my CHC from floating out. Cut it to shape with metal sheers, folded over the container lip, and used a few big rocks to hold it down while soaking.

    TIP 2 - Indoors!:
    Its too cold outside now, so I had to soak mine inside. I used a big storage bin as a soak bin to put my containers in. They were placed next to the door so I could just move it outside while dealing with container dunking/removing, then brought inside for the night to soak.

    NOTE: creepy crawlys will flee from your soak-pit-of-doom! So if doing this indoors, be ready with some tacky tape around the edge of the bin to catch them. Tanglefoot ideally. I had centipede's coming out I didnt even know I had, as well as the gnats fleeing to the edge and climbing out. Duct tape didnt seem to stop the gnats. try packing tape maybe, fly tape, or the best idea is probably tanglefoot.
     
  20. Millet

    Millet Well-Known Member 10 Years

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    Centipedes are actually beneficial insects in containers. - Millet (1,143-)
     
  21. roachslayer

    roachslayer Member

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    Good to know about the centipede. They aren't beneficial running around the house though. hehe.

    Update:
    Soaking strategy is not 100%. There are still tons of live critters after 2 dunks.

    Theory:
    I suspect the reason is, there is air in the medium, inevitably. For example, I have tiny pine-cones, and other junk that fell in during the outdoor season. Bottom line: I dont think the medium (CHC plus whatever) is completely saturated, therefore some bugs find a hide-away and survive.

    Conclusion:
    I will say, most of them are dead. So soaking is a good fast fix for the masses if your plant is at immediate risk. We still need a full 100% long term solution to the gnat problem.
     
  22. Ray from PA

    Ray from PA Active Member

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    roachslayer

    I wrapped the top of my pots in alum. foil to prevent the chc and the fungus gnats from escaping. I even wrapped it tightly around the trunk so they couldn't climb up. After almost a week I have zero activity in my pot, the gnats are gone. As far as I'm concerned this is a 100% effective method of getting rid of gnats in the soil.
     
  23. roachslayer

    roachslayer Member

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    Well Ray, I dunno how you did it. Are you super sure yours are ALL dead?

    I've done several plants now with no luck on 100% gnat death. I'm estimating at least a 10% survival rate. Doesnt matter whether I use foil, spray neem oil on the surface of the water, etc. Some seem to find air pockets somewhere and survive the entire 24hr process.

    I officially hate fungus gnats. I also officially hate scale, but thats in another thread :)
     
  24. Ray from PA

    Ray from PA Active Member

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    I don't know Roachslayer, all I did was cover the top and make sure the tree was submerged up to the trunk. I think I may have an advantage though because I only had one pot that was infested, so after submerging I didn't have any chance of reinfestation from flying gnats. Maybe that's what's happening to your soil?

    All I know is that my pot is now completely 100% gnat free. It's been almost two weeks so if there were any escapees I would have seen them by now.

    Yes, scale is the bane of my existence. I actually consider it to be my arch enemy.
     
  25. roachslayer

    roachslayer Member

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    True, reinfestation would happen with multiple pots if I wasnt careful, but I am isolating the treated plants from the non. More frustratingly is that I see the Live critters in the pot immediately after draining the water and removing the foil. There they are (at least a handful of them), crawling at the surface, laughing at my failed slaughter attempt.

    Water submersion is effective, but not completely. Cinnamon is 99% NON-effective. Sorry Hollyberry, I dunno what to say. Maybe thats some special cinnamon you have.

    Time to bring out the big guns:
    I am now considering adding Gnatrol to the water when I submerge. I am trying to research to be sure this wont harm citrus, but no definitive info yet. I might have to experiment on one of my plants and see how she does!
     

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