Getting rid of Nats/indoor pests

[Scrogdor]

Any suggestions how to get rid of these for an indoor tiger bark ficus? Looking for a solution for INDOORS, the tree has been growing fine under a grow light and it's watering schedule for the past 3-4 months. I tried Bayer 3 in 1 insecticide, didn't seem to work. Also tried neem oil. It's in pretty free draining soil, only organic component are pine chips. When I introduced moss to the soil is when they first appeared. I've taken off the moss and put that outside, hoping this helps.

Would drowning them work? Like submerging the soil for 5 minutes?

 

[Tums]

The imidacloprid in the Bayer should have worked, but maybe it's too dilute? The problem is if you're watering all the time, you'll just flush the insecticide out. Imidacloprid also comes in time-release granule form.

Dunking the plant to drown the gnats could help but it's gotta be longer than 5 minutes. This website said an hour and this one said a whole day (not sure about that).

 

[Scrogdor]

The imidacloprid in the Bayer should have worked, but maybe it's too dilute? The problem is if you're watering all the time, you'll just flush the insecticide out. Imidacloprid also comes in time-release granule form.

Dunking the plant to drown the gnats could help but it's gotta be longer than 5 minutes. This website said an hour and this one said a whole day (not sure about that).

So I dunked it for about 15 minutes, removed the moss. top layer of soil floated off. I replaced with dry soil. Sprayed surface with bayer. If this doesn't work I'll try a longer dunk next week

 

[Tums]

Sprayed? Oh, I thought it was one of the drenching products. The gnats like to live below the surface of the soil too.

 

[hinmo24t]

mosquito bits

 

[Wires_Guy_wires]

Gnats are drawn to rotting roots. They should not be an issue in a healthy system.

 

[hinmo24t]

Gnats are drawn to rotting roots. They should not be an issue in a healthy system.

just reminded me...a way some ppl deal w fungus gnats is to let the soil dry out and they wont want to be in there


for mosquito bits, top dress. they work well for me

 

[Colorado]

Insecticides for fungus gnats are just a band aid, not a long term solution. Some would argue the deluge of ‘cides is actually making the problem worst by introducing more salts into the soil system, weakening the tree immune system even further.

The long term solution is inorganic substrate, proper watering, and healthy roots.

 

[sorce]

Centipedes work too, I usually bring them in with the moss. I'd go get more.

The gnats will show up on Mars if the soil is too wet.

Better to have wet soil and centipedes than dry soil and a dead tree.

Plus...

With half inch pots being a reality, even if not personally probable, keeping yourself trained for the most difficult scenarios make the regular ones a breeze.

Sorce

 

[canoeguide]

 

[Deep Sea Diver]

Fungus gnats eat fungus. If you want to get rid of fungus gnats get rid of the fungus. The problem is that once fungus gets started, its hard to stop the lil living things from doing their things.

Last year was my first major year for raising azalea cuttings out here. Over a hundred and fifty. I watered too much and fungus decided that the media was a nice place to live. Along came the gnats, larvae and all. I spent a long drawn out proces to get rid of them. I used mosquito bits, H2O2, safer soap etc. They knocked down the gnats down to almost nothing, but not totally. The only thing that worked was to put the cuttings outside when the weather turned.

This year I started off using a stronger amount of H2O2 for daily spraying and watered less and made over 450 cuttings. So far so good. It’s been 4 months. I’m not using mosquito bits presently.

It you already have fungus gnats you’ll have to hit it on both ends. I’d recommend safer soap be sprayed directly on the gnats when you see them. Keep the media on the dry side and use up to 1 TBSP per quart 3% H2O2 (1.5 tsp/qt for maintenance). I believe a 3x stronger concentration one time would be ok, but do some more detailed research on this topic on your species before using higher concentrations.

Good luck!
DSD sends

 

[canoeguide]

The gnats will show up on Mars if the soil is too wet.

Absolutely this. Every fall when my tropicals come inside, the fungus gnats show up as I adjust from the "flood everything" outdoor watering routine to the more-precise winter routine. The #1 solution is proper watering that allows the soil to not stay too wet. I help things along and make sure to eliminate any of the larval stages in the soil with Mosquito Bits, and all is well.

 

[Glaucus]

It is indeed said that the fungus gnats eat ... fungus. But I think they eat any organic matter. Including the fine plant roots.

Using sticky traps works well on the flies. But ideally I want to kill the larvae. I tried nematodes and mosquito bits. Neither of them got rid of them completely and I did not have a control. Therefore, it is hard to say what their effect was.

I will try H2O2 now. I got a bottle of 35%. So I will have to dilute that 100x at least, haha. Then test it out to see if it doesn't kill azalea seedlings.

The gnats appear spontaniously from any potting soil.

 

[Carol 83]

The gnats appear spontaniously from any potting soil.

I have been keeping trees indoors for years and have never had gnats.

 

[Wires_Guy_wires]

just reminded me...a way some ppl deal w fungus gnats is to let the soil dry out and they wont want to be in there


for mosquito bits, top dress. they work well for me

I've battled them for a decade before I finally caved and just monitored my watering better.
Chopstick, in the soil, check before watering. End of all gnat issues. It was as simple as that. If the chopstick is damp, no watering. If it's dry, water.

I give advice to some indoor gardeners and I'm a decade long member at some gardening forums.. Please don't see this as critique or an attack, it's a general observation about gardeners: People just don't want to understand that you can get rid of the entire fungus gnat issue by - you wouldn't believe it - actually taking good care of your plants. You can soothe a burn with aloe salve, and order buckets of it delivered to your doorstep, but it's way easier not to stick your hands in a fire in the first place.

We can't get mosquito bits around here, but we can get horse manure dewormer with the same ingredients (yes, deworming the manure, not the horse). And that stuff kills gnats dead. But gnats or no gnats, if they have been there, there was a watering issue that needs to be addressed. I can't count the amount of times people blamed the gnats for eating away their precious overwatered and already dead houseplants. That's like blaming raccoons for dumpster diving in an open dumpster.. The best way to keep raccoons away is to not open up a buffet for them. I think gnats work in a similar fashion.

@Deep Sea Diver sorry for tagging you so often today. Plants do have peroxidases and catalases, and from what I've seen a 3% solution does very little harm. If the foliage is damaged, the H2O2 will chomp down on it and cause it to turn brown around the edges, but not a lot more than regular damage related abscission would over time. As far as roots concerned, there's so much alive in a soil that the 3% is down to about 0.003% in a couple minutes. If you have a good nose, you can actually smell acetic acid evaporating from who knows what kind of reaction. In microbial identification, a peroxidase/catalase test is a standard operation for classification. It's not as cool looking as a coagulase test, but it is a funny fizzy test to perform. Works on humans too! Drop some 3% H2O2 on a scab or a fresh wound and it'll fizz up (and be disinfected).

 

[Glaucus]

I indeed could not find a EU place that sells mosquito bits. But just before Brexit, I got a pot form UK amazon.

So would you say that H2O2 is pointless against gnats? I realize the peroxidase reacts very quickly. But it might damaged the fragile larvae much more than the plants.
I germinate seedlings under 100% humidity, so drying the soil out is not an option. Also, do you believe the gnat larvae eat the fungus that grows in these moist conditions? And when it gets drier they starve because there is no more fungus?
Or are they eating organic material and they themselves need the moisture?

I am also thinking about experimenting with a tray I use specifically for the flies to lay their eggs in. I tray I can nuke with H2O2, freeze outdoors, dry out completely. Any eggs the flies put in this 'lure tray' do not get laid in my seedling trays. And none of those eggs should be able to produce mature gnats.

Ah yeah, the catalase test for bacteria. Catalase, the fastest enzyme in the west. I preferred it to blood coagulase tests, actually. Maybe I just like the bubbles?

 

[Deep Sea Diver]

Lots of cool stuff... an ounce of prevention.... I looked for the proper concentration that can be used against fungus gnats to be effective on eggs and larvae once an infestation has occurred and came up with this article by Pistils Nursery in Portland. Here's the excerpt on eradicating Fungus Gnats. Let me know what you all think about their method.

Fungus Gnats

We get a lot of questions about fungus gnats, which thrive on high humidity and moist soil conditions. You may find them hanging out around ferns, Marantas, or other moisture-loving plants. Fungus gnats are an unsightly nuisance. Fruit fly-like, they hop or fly about your plants, especially when disturbed. However, it isn’t the gnats that do the real damage. It’s their larvae in the soil that eat rotting material but also tender new roots. A serious infestation can weaken a plant over time, leaving it pale and drooping. Populations can grow quickly, since fungus gnats lay somewhere around 300 eggs at a time. The first thing to do if you detect fungus gnats is to let the soil dry out as much as you can without causing your plant stress, since fungus gnats require constant moisture to survive.

A surprisingly easy, effective method for controlling fungus gnats is hydrogen peroxide! Simply mix one part 3% hydrogen peroxide with four parts water and water your plant with the solution. The peroxide will make quick work of any fungus gnat eggs or larvae. It also happens to oxygenate the soil and flush out compromising bacteria and fungal growth, making your plants extra happy and healthy. You may have to repeat the treatment a few times to catch any new eggs laid by adults.

If this still isn’t helping, consider releasing beneficial nematodes (microscopic predatory worms) into the soil which can make quick work of fungus gnats, or completely repot and replace with fresh soil.

It turns out that when I used H2O2 as a deterrence dose vs eradication dose it worked and that's why it was ineffective once an infestation occurred.... or maybe I just water better nowadays!

Also that there are many gardener sites that recommend using Hydrogen Peroxide for eradication... This one Pinch of Seeds has an expanded discussion..... sorry about all the ads.

Cheers
DSD sends

 

[Scrogdor]

Update:

So I soaked the soil for one hour, and then re sprayed the tree/soil with 3-1 Bayer, got rid of all moss on my indoor bonsai. Gnat population has probably gone down 80-90%. When I disturb the surface soil I don't see 4-5 gnats scurry around, now I maybe see one. Although my Tiger Bark Ficus was stressed out a little bit from the soak it seems, as it was dropping some leaves over the past couple weeks. It seems okay now though.

I will try the Hydrogen Peroxide method!

 

[Scrogdor]

I have been keeping trees indoors for years and have never had gnats.

I did this to myself by bringing moss inside that I collected. The issue has gone down significantly since I got rid of the moss.

 

[leatherback]

re sprayed the tree/soil

This will not do anything. It is the larvea and eggs you need to get. Just hit-or-mis spraying the adults makes no difference. For every adult you see, 100 larvea are in the soil

just monitored my watering better.
Chopstick, in the soil, check before watering. End of all gnat issues. It was as simple as that. If the chopstick is damp, no watering. If it's dry, water.

Yup, its what I have been advocating for a loooong time too.
Bottom watering helps here: You can let the top of your substrate get fairly dry (As a deterrent) and sparingly water the plant over a shallow dish below the pot. This is how my tropicals get treated when they first come in.