Coming back from fungus gnats!! Help

MedicineMan303

New Member
recently had an infestation of gnats and got some BTI product and sticky cards to work on killing these fuckers! My question is in regards to recouping from this. I have a lot of yellowing leaves and want to know if you guys have any remedies or additives to help these ladies get back to 100%!? Thanks for anything!!!
 

charface

Well-Known Member
It didn’t start until I noticed the gnats. Could be a nitrogen deficiency as well. Have you ever seen symptoms from gnats?
No, that's why I asked.
Not saying they cant do damage to the roots, I've just never seen it.


I just wanted to be sure you knew the cause before you treated them.

If you post pics and give details of your feed, soil etc.

Maybe someone can verify the cause and get you on the right path
 

MedicineMan303

New Member
Oh ok I see. And yes I had a couple opinions as far as the cause of the yellow and the only other thing We thought it could be was a nitrogen deficiency on top of the gnats giving us a double whammy.

And I haven’t noticed any serious root problems, just the majority of the gnats on the topsoil. Also read online that this is where their larva are laid.

As far as nutrients I’m just running a general hydroponic flora nute with a added sweet raw in a coco with pear lite media.

Side note: could this be a overwatering problem? How often and how much do you wanted each plant?
 

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gjs4786

Well-Known Member
Oh ok I see. And yes I had a couple opinions as far as the cause of the yellow and the only other thing We thought it could be was a nitrogen deficiency on top of the gnats giving us a double whammy.

And I haven’t noticed any serious root problems, just the majority of the gnats on the topsoil. Also read online that this is where their larva are laid.

As far as nutrients I’m just running a general hydroponic flora nute with a added sweet raw in a coco with pear lite media.

Side note: could this be a overwatering problem? How often and how much do you wanted each plant?
The gnats could definitely be a symptom of an over-watering problem. I don't think the yellowing is a symptom of having fungus gnats. I think everyone gets fungus gnats. Rather than eradicate them, keep their numbers down by watering properly.

One thing you want to rule out are Root Aphids. They can cause the symptoms you're experiencing and at certain stages in their life cycle, can resemble fungus gnats. Here is something I copied from another website, linked below, that explains it well:

"Root aphids cause stunted growth, and droopy or yellow leaves resembling nutrient deficiencies. The yellowing (chlorosis) resembles a magnesium deficiency, and the yellow-brown spotting a calcium deficiency. If you have checked pH (feed and runoff), and know that your plants are being properly fed, you should probably check for root aphids. They feed by sucking nutrients directly from roots before plants can use them, so their damage isn’t obvious at first. Rule out pH problems quickly and carefully inspect any plant with signs of a deficiency."

Linked from: https://waytogrow.net/blogs/articles/root-aphids-no-they-re-not-just-fungus-gnats

Don't forget to rule out pH problems as it states above.
 

MedicineMan303

New Member
The gnats could definitely be a symptom of an over-watering problem. I don't think the yellowing is a symptom of having fungus gnats. I think everyone gets fungus gnats. Rather than eradicate them, keep their numbers down by watering properly.

One thing you want to rule out are Root Aphids. They can cause the symptoms you're experiencing and at certain stages in their life cycle, can resemble fungus gnats. Here is something I copied from another website, linked below, that explains it well:

"Root aphids cause stunted growth, and droopy or yellow leaves resembling nutrient deficiencies. The yellowing (chlorosis) resembles a magnesium deficiency, and the yellow-brown spotting a calcium deficiency. If you have checked pH (feed and runoff), and know that your plants are being properly fed, you should probably check for root aphids. They feed by sucking nutrients directly from roots before plants can use them, so their damage isn’t obvious at first. Rule out pH problems quickly and carefully inspect any plant with signs of a deficiency."

Don't forget to rule out pH problems as it states above.
Awesome!! This is most helpful for sure!! That’s not something I even knew existed. I will have to go through and check all of my ph levels again thoroughly as well as my roots. Any idea how to identify them? I’ll also have to do some research regarding these little bastards if it is them and have a new plan of attack. I also attached the section I’ve been reading regarding the gnats.
 

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NaturalFarmer

Well-Known Member
Looks like you are in need of Magnesium from that picture as well as maybe a more balanced feed. Mag will cause yellowing of the leaf but the vein will remain green.

Fungus gnats are a pain but manageable.
BTi for larvae will be of help. A small vacuum for fliers can be helpful as well.

fungus_life_cycle.jpg


Root aphid have tailpipes as see in the arrow
f1.gif
 

gjs4786

Well-Known Member
Awesome!! This is most helpful for sure!! That’s not something I even knew existed. I will have to go through and check all of my ph levels again thoroughly as well as my roots. Any idea how to identify them? I’ll also have to do some research regarding these little bastards if it is them and have a new plan of attack. I also attached the section I’ve been reading regarding the gnats.
Keep in mind, the picture associated with the fungal gnat infection you posted is a severe case. When fungus gnats are killing your established plants, like in that pic, you would have gnats everyyyywheree. As far as identifying root aphids, I suggest the website I posted earlier: https://waytogrow.net/blogs/articles/root-aphids-no-they-re-not-just-fungus-gnats.

This is what I would do, in order.
Determine if they are root aphids or not.
Check your pH
Try a hydrogen peroxide treatment for the gnat larvae if they are indeed fungus gnats.
Improve watering frequency...they thrive when you water too often.
Put out sticky cards to catch the adults.
Increase air circulation.
Check pH again.

The tricky part is figuring out if the physical symptoms of your plant is caused by a nutrient deficiency (or excess), pH imbalance, pest infestation, or a combination of them all. So in this case, I might treat for fungus gnats first, then do a pH check, if that checks out OK, then either it's a different pest causing problems, or too little or too much fertilizer.

Another thing to keep in mind is how the plants leaves are yellowing. If they yellow from the bottom up, more than likely a deficiency. If it's top down, you can pretty much rule out a nitrogen deficiency. Look into mobile and immobile nutrients. I think mobile nutrients will start from the bottom up and immobile show up anywhere. I'm not an expert though, far from it, just trying to help.
 
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