Fungus gnats -- some good inexpensive ways to dispense with them

[orchidsarefun]

along with earthworms, pillbugs,centipedes and millipedes that were brought in from the garden with my Catts, I also have at least 2 jumping spiders. I have watched them moult from tiny pinhead-sized spiders to at least 3 times the size. The good thing is that they are voracious and are keeping the fungus gnats under control. I only see 3-5 gnats flying around. My yard is full of these spiders in Summer, so I think I am going to have an in-built organic control cos I outdoors my catts, maybe try with the phals as well in 2012.
The p, c & m are disappearing because I drench water and they are flushed out.
The jumping spiders know when I am gong to water and get outta da way
BTW - I notice that the gnats spend more time underneath the pots as around the leaves. For those of you that are going to spray, please take note.

[Rowangreen]

Right, so this could be why the flies I've had the last few weeks are ignoring the fruit fly traps!

Off to try and find one for a closer look, but meanwhile this webpage I found might be of interest to folks in the UK:

BBC - Gardening - Advice: Pest and disease identifier

[Rowangreen]

For UK folks: I've been doing massive searches... I did find one person selling Mosquito dunks on ebay in the UK (2 for about £11) and some sources of Gnat Off: which are both bacteria based control from the US.

You can also get nematodes and mites which control the larvae. If you look for 'Sciarid fly control' you'll find them. I think I might be trying some nematodes: mites seem to be more recomended as a preventative, and the nematodes are marginally cheaper. Sounds like the nematode powder can be kept longer... though the mites might establish as a long term population in your pots... Not totally decided yet!

While researching I've also tried pots of cider and wine vinagar (pretty useless), covering yellow covered things with vaseline (including card and banana skins): they happily ran all over them, and homemade sticky traps with parcel tape and selotape (seen several land on the parcel tape, most got off again. Not yet seen any land on the selotape)

Meanwhile they've been comiting suicide in the shallow bit of water that gathers on one part of my draining board (maybe shallow is the trick?) and my cat's water bowl (cream coloured). I've also found when I turn the kitchen light off for the night (I have a grow light on all day) they come through into the livingroom and make swatting targets. I'm thinking of also getting an electronic fly swatter...

At present I'm letting all my pots dry out a bit except one with no plants and nice moist potting compost which I'm intending to chuck in a few days. Hopefully the flies will all lay in there! Also might get sharpsand for the top of my plants other than orchids.

[Discus]

I find commercial yellow sticky traps seem to catch quite a lot of them (more than blue, that's for sure). Also, the cape sundews I've grown from seed seem to be having quite a fun time with them. *evil grin*. I haven't been able to find any butterworts down here so far.

[Orchid126]

You might try raw potato slices. Make sure they're juicy and not dry. Put a couple on top of the medium. The next morning the underside should have black specks on them. Wrap them and toss them in the trash and put on fresh potato slices again.

[kalanchoe]

I had good luck with the yellow sticky traps coupled with changing out affected medium. I bought the mosquito dunks along with the yellow sticky cards at the time of the infestation, but never had to use the dunks because the sticky cards plus changing medium did the job. It took a while, with the numbers of gnats slowly dwindling over several weeks.

[NYCorchidman]

Fungus gnats,,,don't we hate them? only if you've ever suffered, you know how annoying they truly are.

Those little suckers somehow came into my apartment (I believe through a houseplant I bought) in January. They multiplied very fast and by the end of february, I was killing nearly one hundred every morning!!! I killed them with my hands everytime I saw them, which is still part of my morning routine. lol
I reduced their population quite a bit this way, but they still persisted.

I found some info on the internet, and ordered the yellow sticky traps and mosquito dunks from repotme.com. Well, someone above mentioned yellow sticky worked for them, but it didn't work for me. Actually, I never saw a single bug caught on them. Maybe the ones in my apartment were all colorblind. lol

The mosquito dunk uses naturally occuring soil bacteria that kill the mosquito larvae. This microorganism also kills the larvae of fungus gnats.
You can mix it with water and then just pour the mix onto the soil as you would water your plants. The only thing with this method is it only worked for my houseplants potted in soil that stays wet (this is necessary for the bacterium to stay alive and do its job;killing the other bugs!) other than orchids.

While I still saw fungus gnats flying around my orchids, there were much less of them after trying this method on my other houseplants where, at least in my case, most of these little bugs seem to live in.
From killing hundreds a day to just a few a day. Trust me, there were much less frequent clapping and squeezing in the apartment.

During the summer, they all seemed to disappear, and now that the weather is getting colder, they are back in my apartments. They either endured through the summer heat in the soil and came back out now, or they hitchhiked into my apartment on one of the amaryllis I recently purchased. It is amaryllis season! I have a few pots of amaryllis and a few orchids that are potted in moss that stays moist all the time and I belive these are where the bugs live and reproduce. I read that these bugs can lay hundreds of eggs every day while they are alive (about 10 days), 10% of which hatch, then the larvae period is for about two weeks.

They are very very annoying, but I find that they don't really harm my plants in any way.
Throwing all the other houseplants might solve the problem, but I love my amaryllis very much.

So I just live with fungus gnats now. just have to kill a few every morning. lol

[NYCorchidman]

someone mentioned it earlier and I was just wondering if that's safe for the orchid roots.
I thought about doing that, but I wasn't sure the harm it might cause.

One time, I brought home a little oncidium with tons of flowers. Close examination confirmed those little flowers were heavily infested with aphids all over. I literally freaked out as I had lots of other plants that I surely did not want any aphids transfer to.
I didn't want to buy any strong chemical, so instead I just mix rubbing alcohol (not sure if I used 90% or 70%) with some water and sprayed the mix all over the plants focusing on the flowers.
Within minutes, all the bugs dropped dead. I was so happy thinking I got the issue under control, well, I did, but in the following few days, all the little flowers started to fall off and within three days, I lost every single flowers.

So back to the point, anyone tried spraying alcohol on the roots, any harm done or no???

[silken]

I sprayed alcohol mixed in water and it also went into the media and killed my orchid. Maybe had I waited 10 mins and then flushed the media with clear water, it would have killed bugs and not the plant-who knows! Or if the plant is bare root and you do it, wash off, then re-pot may be OK, but I haven't tried it.

[NYCorchidman]

Originally Posted by silken

I sprayed alcohol mixed in water and it also went into the media and killed my orchid. Maybe had I waited 10 mins and then flushed the media with clear water, it would have killed bugs and not the plant-who knows! Or if the plant is bare root and you do it, wash off, then re-pot may be OK, but I haven't tried it.

Wow~ your orchid died after being showered by alcohol mix? That is the worst nightmare!!!
See, my orchid dropped all the flowers but survived.
I think if alcohol mix is strong enough to kill bugs, then it surely can damage the plant roots to a certain degree.
In your case, to the extreme.

Ok, I think I will not spray alcohol mix on the media, then. I'm sorry to hear that you lost your plant by the way. hope it wasn't something very valuable or a long time family member.