Fungus Gnats - Why are they a problem?

[solid7]

I have fungus gnats. Tons of them, in fact. Everytime I get close to my containers, I see a swarm of them. And yet, my plants look gorgeous. What exactly is the problem that all of you see with them?

Because I raise everything organically, and use lots of both composted and uncomposted materials, I actually expect fungus gnats, and have always figured that they were a healthy part of the process of breaking down organic material. Maybe they are a problem with a grow that uses chemical fertilizers, where the choice organic material for the maggots to feed on, is the tender young roots?

I don't see them as pests, and don't plan on doing anything to get rid of them, lest I disrupt the balance of the micro-ecosystem that I've already started to develop. Does anyone else see this as a valid thought?

 

[Nightshade]

I just dont want gnats flying in my mouth

 

[solid7]

I just dont want gnats flying in my mouth

You just gotta pick the peppers with your hands instead of your teeth.

 

[Helvete]

gnat larvae feed on root rot fungus...but are a catch 22, they also carry the fungus on their bodies.  without healthy soil/roots you can end up with dead seedlings.

 

[Nightshade]

You just gotta pick the peppers with your hands instead of your teeth.

lol but no seriously I havent seen them cause any major damage there are much worse bugs to worry about. I just dont like gnats especially indoors

 

[Cayennemist]

gnat larvae feed on root rot fungus...but are a catch 22, they also carry the fungus on their bodies.  without healthy soil/roots you can end up with dead seedlings.

 
this^^^

 

[John1234]

An overabundance of one factor of a web isn't a balanced system....

 

[geeme]

I don't see them as pests, and don't plan on doing anything to get rid of them, lest I disrupt the balance of the micro-ecosystem that I've already started to develop. Does anyone else see this as a valid thought?

 
No. I spent about 6 months in Georgia for business. At some point in the past someone thought it would be a great idea to bring in kudzu for groundcover purposes. Worst. Mistake. Ever! Drive through many sections of Georgia now, and you find the invasive kudzu everywhere - including covering giant trees like a canopy, and even causing tree death. The above statement makes me think of that. While I understand your thought process, as ikeepfish said, you're not going to end up with any fresh pods that way. Here's an alternative to other, less-healthy stuff to kill off the fungus: http://www.using-hydrogen-peroxide.com/gardening-with-hydrogen-peroxide.html
It won't necessarily stop the gnats and their larvae, but will at least down the fungus itself. I use buglogical.com to get ladybugs, they also have other beneficial insects you might consider.

 

[Weed]

Why are they a problem?
 

 
The larvae not only eat fungus, they eat roots. Seedlings dont have many roots which usually means death. I have personally dug up seeds that were invaded and killed the minute they opened for germination.
 

Does anyone else see this as a valid thought?
 

 
No. You might think you have a balanced ecosystem but you dont. Where are the fungus gnat predators? An overabundance of this type of organism will only lead to an overabundance of disease and plant death. You can go against a hundred years of communal gardening and growing experience if you want but you will no doubt come to the same conclusion eventually.

 

[Jeff H]

 
The larvae not only eat fungus, they eat roots. Seedlings dont have many roots which usually means death.

 
 
MX is pretty much right on target. Gnats vs. seedlings = plant death. gnats vs. larger plants. = no real issues if there aren't too many.
I've pulled dead seedlings that have been attacked by the gnat larva. There isn't much more left than their stem. Roots are all but gone.

 

[millworkman]

Like others have said, its the babies that die from the gnats.  

 

[Indiana_Jesse]

Yep, they are not an issue with good sized/large healthy plants, but they WILL eat the roots to sprouting seeds causing death, and also slow down growth (or slowly kill) small seedlings. Ever have a seedling mysteriously fall over without wind being a factor, because they barely have a root system? I usually avoid this by keeping soil dry until use, and then sow seeds right away after moistening, but if the seeds take more than two weeks they might be goners (if you have large amounts of fungus gnats like me).

 

[solid7]

I only see the issue when I grow in grow plugs, or small seedling trays. I generally start seeds in a larger container with lots of organic matter. So, I guess it does make sense. Fungus gnats only inhabit the top 1-2" of the potting strata. So I could see where growing seedlings in trays could be a real issue.

I guess I was curious, because I have actually never seen a problem with fungus gnats of any sort, with seeds planted in the ground. We have a ficus tree in the backyard, and the leaf litter is teeming with them. But never a problem, even with seeds. (worms are a different story)

 

[geeme]

I guess I was curious, because I have actually never seen a problem with fungus gnats of any sort, with seeds planted in the ground. We have a ficus tree in the backyard, and the leaf litter is teeming with them. But never a problem, even with seeds. (worms are a different story)

 
Heh - you may be confusing who the culprit is. Worms vs. fungus gnat larvae, and you think the worms are a problem? 

 

[solid7]

Heh - you may be confusing who the culprit is. Worms vs. fungus gnat larvae, and you think the worms are a problem?

No confusion. My seedlings in the ground have all come up fantastically. When a cutworm or hornworm sneaks in, that's big trouble. Fungus gnats (for me) are harmless. I've got millions of fungus gnats, and that's no joke. LOL

Now, I understand they are annoying, and can be a problem in small spaces where roots are the best choice of available organic matter. I had a real problem with them once in some seed trays that I started in grow plugs. Probably won't do that again. My seeds have all come up problem free in 2 and 3" pots. (even with the fungus gnats and larvae obviously present) I don't do sterile soils with synthetic fertilizers. Makes me wonder if that isn't a big part of the problem... Any thoughts on that?

 

[Weed]

What trouble do you have with worms? Do you mean the cutworms and hornworms?

 

[solid7]

What trouble do you have with worms? Do you mean the cutworms and hornworms?

Yeah, the cutworms strip the leave and or cut off the seedlings, whereas the hornworms eat the whole damn plant. It's usually not too big a deal, as I plant several plants at once, and I'll find them by the time they get a couple seedlings.

You guys sound surprised that I mention worms, but I am talking about growing outside...

 

[Weed]

Because the rest of the world uses "worm" to mean an earthworm.

 

[solid7]

Because the rest of the world uses "worm" to mean an earthworm.

Ah. Fair enough.

No, I have no problem with earthworms. It's the "other" worms that I have constant issues with. For my containers, I actually consider the fungus gnats beneficial. As odd as that may sound.

 

[Weed]

Maybe in an area that is warm and humid there is more of a need for them. I can see them being beneficial in an established system. But trapped inside with seedlngs they are a menace.