# Fungus Gnat vs Nematodes



## minorhero (Apr 24, 2020)

I saw this in another group. Folks were asking about how to deal with fungus gnats and one suggestion was to add beneficial nematodes. First time I had heard of this solution and as someone who is currently waiting out a really annoying fungus gnat problem for the past 3 months it has a lot of appeal if its not harmful. 

Thoughts?


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## fishingguy12345 (Apr 7, 2019)

minorhero said:


> I saw this in another group. Folks were asking about how to deal with fungus gnats and one suggestion was to add beneficial nematodes. First time I had heard of this solution and as someone who is currently waiting out a really annoying fungus gnat problem for the past 3 months it has a lot of appeal if its not harmful.
> 
> 
> 
> Thoughts?


Frogs... Chasing gnats... Fun times 

I'm not a big subscriber of adding things to get rid of other things in the vivariums.


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## Encyclia (Aug 23, 2013)

Haven't had a biology class since the Clinton administration, but I seem to remember that this type of biological control rarely, if ever, works out and is responsible for some of the worst invasive species situations on the planet. Every fungus gnat situation I have ever encountered has worked itself out, including one in a springtail culture I had recently  3 months is a long, annoying time, though, minorhero. I don't blame you for wanting to take a more active role. Not sure that's the way to do it, though. Can't imagine that the nematodes would only eat fungus gnats and just give up on life when they were gone.

Mark


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## minorhero (Apr 24, 2020)

Encyclia said:


> Can't imagine that the nematodes would only eat fungus gnats and just give up on life when they were gone.


This is my concern, super easy to add them to a tank but impossible to remove if they are harmful. I saw the suggestion on a vivarium group and I was like 'huh, never heard of this before'. Figured I would run it past the posse ;P


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## Rusty_Shackleford (Sep 2, 2010)

How do you know if it's a beneficial nematode or a.harmful one?
Nematodes are usually very species specific and there are nematodes that could kill ypur frogs. 
When in doubt, leave it out. 

Sent from my LM-Q710(FGN) using Tapatalk


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## Socratic Monologue (Apr 7, 2018)

Rusty_Shackleford said:


> How do you know if it's a beneficial nematode or a.harmful one?


The species in question is _Steinernema feltiae_, which is apparently pretty well researched. I couldn't find anything that indicated danger to amphibians.

_S. feltiae_ does reduce survivability of isopods:

https://www.sciencedirect.com/science/article/abs/pii/S0022201108000207

Also, springtails consume the nematodes in their infective juvenile stage (the stage they are used in):

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6023359/


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## Kmc (Jul 26, 2019)

Encyclia said:


> Haven't had a biology class since the Clinton administration, but I seem to remember that this type of biological control rarely, if ever, works out and is responsible for some of the worst invasive species situations on the planet. Every fungus gnat situation I have ever encountered has worked itself out, including one in a springtail culture I had recently  3 months is a long, annoying time, though, minorhero. I don't blame you for wanting to take a more active role. Not sure that's the way to do it, though. Can't imagine that the nematodes would only eat fungus gnats and just give up on life when they were gone.
> 
> Mark


Agree, these types eco role play usually stay in the theory arena.

If no harm the most that usually happens is thriving populations of both "prey" and "predator." 

Gnats are fragile when fave hang out zone is discovered and dealt with.


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## Pubfiction (Feb 3, 2013)

I think its worth a try, there are lots of questions and only really one way to answer them. 

How effective would they be against larvae of fungus gnats?
Would they decimate your isopods or any other fauna?

However, there is one major caveat to all this. Generally, fungus gnats are working off of something in the soil and until its exhausted, they will keep coming back. So anything you do to control them could just prolong their existence. It's the same reason I dont really worry about mold, I just let it run its course.


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## Kmc (Jul 26, 2019)

It would be an interesting experiment, but so many variables would not seem to be touched as vivs are so individually dynamic in fodder.

I guess when I think of a gnat bloom I see it as benign and self limiting, and when I think of nematodes I think of obscure life cycles and trans hosts, and possibly not benign so i perhaps have a precautionary bias.

If the media were abundantly supportive with alot of gnat attraction I guess I just see it as complicating a simple problem, but I could definitely be short sighting it.


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## Pubfiction (Feb 3, 2013)

You dont have to touch on all variables, experimentation is built over time. IE try it out, if the problem is solved and nothing goes horribly wrong you can say that happened. Then at some point, another person will try it. Eventually, it will become an accepted or rejected practice. 
A really good example would probably be great stuff foam. The first time someone tried that was probably pretty experimental the same is true for most of the highly synthetic chemical components we use. Drylock, etc.... 
Even shipping itself had to be experimental at one point and chances are no one stuck a battery powered thermometer that records temps every 1 hour in a couple hundred packages and sent them all over the country or world to figure it out.


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## Kmc (Jul 26, 2019)

Whatever's right..


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## DBendit (Aug 15, 2020)

I've used the beneficial nematodes in both a bioactive viv housing mourning geckos and a tinc, as well as a millipede bin. In both cases, the fungus gnat numbers dropped drastically and were eventually eliminated. Springtails seem fine, and the isopods in the gecko/frog tank were already being destroyed by that tank's inhabitants, so I can't say if the nematodes had any impact there.

I've also heard good things about mosquito dunks/bits from various groups, as well as Rus from Aquarimax. That might be worth a try.


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## Kmc (Jul 26, 2019)

How do you know it was because of nematodes? Ive had gnats drop drastically from moving a lamp over. Finding the flattened squash that got dragged under the den, or sliding open the doors.


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## Kmc (Jul 26, 2019)

*deductions and diagnostics*

I guess I dont get this thing of wanting to _add more organisms_.

Im veterinary science oriented in husbandry approaches, knowing as much as possible about contacts and effects, risk to benefit.

Simplified: If something ever happens or presents suspicious, you know _what its not_ and can move foward accordingly.


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## Pubfiction (Feb 3, 2013)

I would say he has an N of 2, if a couple more people try it the confidence keeps going up. Sure it could be something else but thats kinda the way that experimentation happens in scenarios like these. Since you mentioned you are in vet science you have probably read case studies. And seen how evidence slowly builds in the identification of a new health problem and eventually a solution. This often is not done in a hardcore high replicatated and controlled experiment. Those experiments are usually done when there are better hypotheses and there is enough evidence to warrant pumping the money and resources in. Unfortunately those resources are not coming to the dart world.


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## Kmc (Jul 26, 2019)

Agreed Pubfiction, a 'collective reef' is built on use and consequence, where standard studies are not available. Heck id even go as far to say that long term observance over a spectrum of scenarios can even be more accurate than some single study examples.

product research before release is startlingly perfunctory sometimes even for human use items.

Also is there is an understandable reluctance to experiment with ones own collection, i have done it, with some personal inquiries of my own, where outcomes would have little chance of a neg outcome just because of their nature. 

I think more folks have modalities they have developed or that they are working on, than they might be willing to share. It would be exciting to have a judgement/debate suspended format or shared blog to communicate such things.


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## aapuzzo (Apr 20, 2020)

What I am about to say is not based on science but just the inner workings of my imagination and common sense in my mind (I might be wrong). If you are adding the nematodes that eat fungus gnats I would think they would also be the same type that go for isopods and springtails. Is this a nematode type that is just going to out compete the fungus gnats for the same food source or actually hunt them? I think it would be easier to get rid of the gnats than the nematodes.

I had a gnat problem last week that resolved itself but I was going to test an invention I dreamed up. 1/4" chicken wire cube with a fly sticky strip in the center secured to the top center of the vivarium where a frog can't go. Also 100% seal up the vivarium except the front holes for a few days so the gnats can't escape. If the frogs are big go an extra day between feedings so they are extra hungry.


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## Kmc (Jul 26, 2019)

Cool Trap Idea. In my minds eye I see a kind of hanging screen tea ball.


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## Socratic Monologue (Apr 7, 2018)

aapuzzo said:


> What I am about to say is not based on science but just the inner workings of my imagination and common sense in my mind (I might be wrong). If you are adding the nematodes that eat fungus gnats I would think they would also be the same type that go for isopods and springtails. Is this a nematode type that is just going to out compete the fungus gnats for the same food source or actually hunt them?


We don't have to imagine how nematodes live -- we have science at our fingertips (Google 'species name' + 'wikipedia'):

https://en.wikipedia.org/wiki/Entomopathogenic_nematode


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## aapuzzo (Apr 20, 2020)

Kmc said:


> Cool Trap Idea. In my minds eye I see a kind of hanging screen tea ball.


That's exactly what I had in mind.


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## aapuzzo (Apr 20, 2020)

Socratic Monologue said:


> We don't have to imagine how nematodes live -- we have science at our fingertips (Google 'species name' + 'wikipedia'):
> 
> https://en.wikipedia.org/wiki/Entomopathogenic_nematode


I see the species name listed. Good to know springtails can eat them in one stage. Nematodes have been the most unwanted thing in my vivariums. I can see them all over monkey pods. I think the frogs ignore them so I can't see how you could possibly get rid of them. I have no idea what type I have been getting besides the largest ones are about 1/2 inch and clear. I seeded with giant orange isopods and never see them but I never dug around either so I wonder if the nematodes have killed them off.


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## Socratic Monologue (Apr 7, 2018)

Well, the ones that pop up in vivs (and everywhere else on earth) are likely decomposers rather than predators. There are 25,000 species with pretty diverse characteristics.


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## Louis (Apr 23, 2014)

I've used nematodes to treat slugs in a vivarium before and it didn't seem to do the isopods and springtails any harm. A year on there's been no sign of any long term negative effects.
For fungus gnats though I would use Dalotia coriaria rove beetles rather than nematodes, I breed these anyway as livefood for my geckos but they are often used as biological control for fungus gnats. Your frogs can also eat the adults and larvae of the beetle as they max out at 5mm.


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## Kmc (Jul 26, 2019)

I feel the need to explain that I have come from a longtime work environment where ill animals were not always granted veterinary care per owner of the facility, especially if they were not an expensive bird, or subject that posed thread of contagion to colonized animals, like rodent feeders eg.

So over the years I had to develop precautionary modalities and thus an embedded austerity of situ - balanced with my own strong lean toward environmental enrichment. I practice what could be called controlled naturalistic.

I was also privy to many peoples problems and mortalities and gathered as much data from these encounters as i could.

There are no mysterious deaths or illnesses, only un discovered causes. Diversity of organisms equals diversity of exposures, not just of the non pathological organism itself but the microorganisms it transports.

I want to put springs in my klappenbachi env but Im picky and want a clean resource. There was a thread here recently that took an unfortunate turn because of a slender factor inquiry - yet this persons springs seemed the cleanest from their described culturing system and i would totally choose them. I never got the chance to tell them.

The bumblebees have established little 'defecatoriums' where i go and tidy with miniature janitor style lol. Or they sometimes go in their faux 'puddle' and its changed immediately. 

The puddle is changed at am and pm, when its clean looking, regardless.

The karma of impeccably clean water in closed system has been one of my hidden discoveries, impossible to prove.


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## greenthumbgecko (Feb 14, 2018)

I’ve looked into the beneficial nematodes for my garden, and one of the things it also kills is springtails, which of course I cultivate as part of my clean up crew. So, I think you are right in passing it by.


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