Fungus gnat outbreak

[abax]

I'm having a horrendous time with gnats. I've been using Gnatrol WDG and
it appears after three applications following instructions that very little
is happening. Might anyone know of another gnat control product that's
more effective than Gnatrol? I'd love to hear about it. Oh, I also have
yellow sticky traps all over the greenhouse and change them regularly.

 

[Ray]

Angela, if it's that bad of an infestation, I think you'd be better off using the Gnatrol AND an insecticide.

Gnatrol is a bacterial infectant that only kills larvae. Insecticides only kill adults. Using both helps break the breeding cycle.

 

[NYEric]

There is an aerosal spray with Lemon oil something natural,blah, blah, blah... at Home Depot, demolishes flying insects.

 

[ehanes7612]

Fungus gnats get a hold on an area when the greenhouse doesnt dry out enough and there is too much dead plant material around. I had this problem then I cleaned up my greenhouse really well, as well as maintaining my backyard better ...also, changed my potting mix to a less organic mix (less bark and got rid of CHC). Fungus gnats mostly went away..you can fight with pesticides but you cant kill all the fungus gnats outside that can re-infest your greenhouse, and the frustration will just continue

 

[cnycharles]

Get some greenshield and apply to wet areas and standing water, takes them out. When they try to land on wet greenshielded puddles or areas they drop right in and toast

Also I hear a rumor that terrachlor fungicide applied to pots can incidentally harm fungus gnats and larvae as it controls fungal issues

Sent from my iPhone using Tapatalk

 

[abax]

Actually, my greenhouse is very clean. I wet/dry vacuum it once a week and
I never, ever have dead plant material lying around.

Ray, I was thinking about using Orthene along with the application of Gnatrol.
I have one more application of Gnatrol to do Sunday. How long do you think
I should wait after Sunday to do the Orthene?

 

[Ray]

Why wait?

 

[ehanes7612]

Actually, my greenhouse is very clean. I wet/dry vacuum it once a week and
I never, ever have dead plant material lying around.

Ray, I was thinking about using Orthene along with the application of Gnatrol.
I have one more application of Gnatrol to do Sunday. How long do you think
I should wait after Sunday to do the Orthene?

Good Luck then..hope it works

 

[abax]

Thanks Ray and everybody else. I did a through drench of Orthene today and
sprayed around the foundations of the gh as well. As to why wait...I didn't
want to OD my poor Phrags. I'm a bit of a coward about using chemicals.

 

[musa]

Sometimes chemicals are unavoidable. I used Chlorpyriflos (don't know if it is the same in english). I don't have any experience with phrags but Paphs had no Problem at al and the gnats were gone completely after one week.
Michael

 

[abax]

Thank you Musa. I'll have to look chlorpyriflos up to see what it is and if it's
available here. Is it a spray or a drench?

 

[musa]

You are wellcome.
I use it as a powder, what is less dangerous than a spray, because it is toxic by breathing it.I found an article on Chlorpyriflos which Im quoting: "Trade names of the CPF include Brodan, Detmol UA, Dowco 179, Dursban, Empire, Eradex, Lorsban, Paqeant, Piridane, Scout, Stipend and other. Currently, for example only in the United States of America, there are over 850 registered CPF products."(BIOLOGICAL EFFECTS ASSESSMENT OF CHLORPYRIFOS AND
SOME ASPECTS OF ITS NEUROTOXICITY by Y. Salyha, Institute of Animal Biology of the NAAS of Ukraine, 2010)
May be useful.
Michael

 

[abax]

Thank you again musa. I'm familiar with Dursban which I think can be
added to water and used as a drench. I never broad spray in my greenhouse,
but drenching the potting medium is a bit safer than suiting up in a haz mat
outfit. ;>)