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Just Asking 15-11-2006 07:04 PM

Fungus Gnats and Pyrethrum
 
I have a few questions:

1) Can you kill fungus gnat larvae by drenching the soil with a pyrethrum based solution?

2) Can you kill fungus gnat larvae with hydrogen peroxide (h2o2)? Will this kill the plants? If not,
what is the best strength?









JoeSpareBedroom 15-11-2006 09:29 PM

Fungus Gnats and Pyrethrum
 
"Just Asking" wrote in message
...
I have a few questions:

1) Can you kill fungus gnat larvae by drenching the soil with a pyrethrum
based solution?

2) Can you kill fungus gnat larvae with hydrogen peroxide (h2o2)? Will
this kill the plants? If not,
what is the best strength?



OK. I'm just telling. I googled for "fungus gnats" and found a wealth of
information in just the first 9 results, minus #4, which was a site for a
company that sells chemicals. The others were all university sites, and very
informative.



Jangchub 15-11-2006 10:47 PM

Fungus Gnats and Pyrethrum
 
On Wed, 15 Nov 2006 19:04:56 -0000, "Just Asking"
wrote:

I have a few questions:

1) Can you kill fungus gnat larvae by drenching the soil with a pyrethrum based solution?

2) Can you kill fungus gnat larvae with hydrogen peroxide (h2o2)? Will this kill the plants? If not,
what is the best strength?


I use Gnatrol, but you can get same results by buying some pond donuts
which are called Bt-Israelensis. Soak the donuts in hot water and
when it cools water the plants. I don't use pyrethrum based poison.
You could also cut way back on watering and get rid of them that way.

Val 15-11-2006 11:10 PM

Fungus Gnats and Pyrethrum
 

"Just Asking" wrote in message
...
I have a few questions:

1) Can you kill fungus gnat larvae by drenching the soil with a pyrethrum
based solution?

2) Can you kill fungus gnat larvae with hydrogen peroxide (h2o2)? Will
this kill the plants? If not,
what is the best strength?


How about quick, simple, cheap, non toxic and always works.......would that
suit you?

Sprinkle the surface soil with ground cinnamon. The gnats disappear within
minutes and apparently it kills the eggs and larva because I've never gotten
a re-infestation in the pot. I was taught this trick by a lovely old man who
had two green houses full of orchids and exotic rare plants. I've used this
method for years with my house plants and told numerous friends and all have
had success and no harm done to any of their plants.

I bought a jar of ground cinnamon at the dollar store and tossed it in my
plant stuff bag I keep in the closet. Whatever is in the spice has no
bearing on price for success.

Give it a try,
Val



TQ 16-11-2006 02:26 AM

Fungus Gnats and Pyrethrum
 

"Just Asking" wrote in message
...
I have a few questions:

1) Can you kill fungus gnat larvae by drenching the soil with a pyrethrum

based solution?

2) Can you kill fungus gnat larvae with hydrogen peroxide (h2o2)? Will

this kill the plants? If not,
what is the best strength?


If the gnats are a problem on houseplants, you can smother them by covering
the potting soil with one-half inch of sand.



Father Haskell 16-11-2006 02:41 AM

Fungus Gnats and Pyrethrum
 

Just Asking wrote:
I have a few questions:

1) Can you kill fungus gnat larvae by drenching the soil with a pyrethrum based solution?


Yes. Also, permethrin family insecticides, synthetic pyrethrins fine
tuned
for better kill and longer persistance.

2) Can you kill fungus gnat larvae with hydrogen peroxide (h2o2)? Will this kill the plants? If not,
what is the best strength?


I've used 3 percent drugstore peroxide cut to 1/2 percent without
causing
noticeable harm. Kills the gnat larvae indirectly, by killing the
fungus
that turns healthy root hairs into gnat food.

Tried cultural fixes? Try root pruning and repotting in clean soil.
Then
cut back on water. Drowned (and dead) roots is what draws gnats.
Near-terminal cases may require taking and rooting cuttings and hoping
the fungus infestation hasn't become systemic.

Have you done a potato test to get a positive on fungus gnat larvae?
I wonder if it would be possible to use spud slices as bait to draw
the little buggers to your dose of pyrethrin or BtI, allowing more
kills with less poison?


Just Asking 16-11-2006 10:34 PM

Fungus Gnats and Pyrethrum
 
"Father Haskell" wrote in message
oups.com...

Just Asking wrote:
I have a few questions:

1) Can you kill fungus gnat larvae by drenching the soil with a pyrethrum based solution?


Yes. Also, permethrin family insecticides, synthetic pyrethrins fine
tuned
for better kill and longer persistance.

2) Can you kill fungus gnat larvae with hydrogen peroxide (h2o2)?
Will this kill the plants? If not, what is the best strength?


I've used 3 percent drugstore peroxide cut to 1/2 percent without
causing noticeable harm. Kills the gnat larvae indirectly, by killing the
fungus that turns healthy root hairs into gnat food.

Tried cultural fixes? Try root pruning and repotting in clean soil.
Then cut back on water. Drowned (and dead) roots is what draws gnats.
Near-terminal cases may require taking and rooting cuttings and hoping
the fungus infestation hasn't become systemic.

Have you done a potato test to get a positive on fungus gnat larvae?
I wonder if it would be possible to use spud slices as bait to draw
the little buggers to your dose of pyrethrin or BtI, allowing more
kills with less poison?


Val and Father Haskell,

Thanks a lot, that is great advice. I expecially will try
cinamon (in combination with neem oil for the adult insects).
And I finally have a good dose for the H2O2 solution.
I'll also try a soil drench with pyrethrum, when my
plants are more established.

Thanks.






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