Fungus Gnats and Insectivorous Plants
 

Hello,

I recently have had an influx of what I am pretty sure are fungus gnats. I was wondering if certain insectivorous plants like the venus flytrap or Nepenthes pitcher plants might be useful in controlling these. I really don't like the idea of spraying pesticides, since my orchids live, primarilly, in my bedroom in my apartment. Do these plants have similar likes and dislikes to phal and paph orchids? Has anyone ever used these plants to control insects? I tried to search the forums, but it came up a little lacking in results.

Just wondering,

John

I'm not familiar with fungus gnats but I do grow a Nepenthes pitcher. It requires lots of humidity. Mine is grown outdoors in a humid environment in damp coir and dappled sunlight. I mist the leaves once a day to bump up the already humid environment. It attracts a variety of insects and utilizes them as it's only source of food. I'm not sure if a fungus gnat would be attracted to the pitchers. My plant gobbles up much larger insects and it's possible that tiny gnats would not provide enough nutrition to support the life of the pitcher plant. A smaller carniverous plant such Venus fly trap might be a better choice, however I'm not familiar with their growing requirements. Perhaps another OB member will chime in with their knowledge on the subject.:)

The butterworts (Pinguicula) are a better choice in my mind. They work great for gnats. Try Cascade Carnivores

The sundews also collect a lot of smaller flying things and are easy to keep. Flytraps require a winter rest in order to survive.

I have a Drosera adelae [you need to use distilled water and keep it in a saucer with an inch of water] attracts a ton of gnats. I have 2 small pinguicula moctezumae and i thought they would not attract as many gnats but one started trapping them.

there are different Pinguiculas so you have to choose the best one for your environment and one that can skip the winter dormancy [think mexicans are best - from what i read].

The Drosera seems a bit more effective - but I had all these for not long enough. also but the Drosera outside and teh sun caused some leaf burn - hope it will recover [the past week has been a lot hotter than the rest of the summer].
Anyway a Pyrethrin based spray works well and it may be less toxic than other chemical compounds.
I had tried neem oil but it leaves residue and damaged some Mango and Lychee seedlings' leaves.

Anyway I think the Drosera is the most effective - it seems to attracts the gnats.
The Venus Fly Trap could not really catch as many. no experience with pitcher plants... wanted to go for the less fussy.

I got the Pinguiculas off ebay... cheap shipping if you buy 2 or 3. if you send me a private message I can send you the link of the seller.

stefano

I had a pitcher plant, it was very fussy and is near dead. I have a few Venus fly traps, Love umm.
They don't eat the nats though. They love black flies and will eat carpenter ants. I haven't had them very long, but theyare very happy. I keep them sitting in water.
Beverly

I add 1/4 tsp of dish soap to a quart of water and use it to water the orchids. Usually once a week for two weeks does it. Though one year I had to do it a third week. Extremely effective. They don't come back until you bring home a plant from somewhere. I use this on house plants too. Carol

That sounds easy enough to try.:thankyou

Thanks everyone for the great responses and recommendations! I have some research to do now.

John

The soup trick should work to get the media dwelling eggs and larvae. Yellow sticky cards help with flying ones, especially in an enclosed space like a bedroom.

Couldn't help but chuckle at all the carnivorous plants recommended. After the little buggies are gone, I envisioned josterha hustling around to find things to feed "Audrey II" (as in The Little Shop of Horrors)

[QUOTE=catwalker808;248877]The soup trick should work to get the media dwelling eggs and larvae. Yellow sticky cards help with flying ones, especially in an enclosed space like a bedroom.

What's the soup trick? :scratchhead:
Beverly

I too had a bit of a fungus gnat problem and after reading an earlier thread here I tried Bacillus thuringiensis subsp. israelensis which can be found in things like Mosquito Dunks or other things designed to kill mosquito larva. It is a bacteria that is non infectious to humans but when the larvae eats it they die.

It's a great way of stopping the life cycle and its safe. I used it in my bedroom.

Sorry. That's SOAP not soup.

I am not sure if I would use a bacterium in my bedroom - I saw some dunks and had some warning words and I think it mentioned outdoor use.

I also use one sticky tape on a rim of a lamp in front of the bulb catches many.
pyrethrum spray works well and does not seem to damage some plants as oil based sprays.

Anyway it you grow orchids a couple of Droseras and Pinguiculas [which have nice flowers as well] help and are fun to grow. they need similar humidity and light as many orchids and they seem to grow offshoots. the gnats decompose quickly with no smell.
you can buy a couple of Butterworts on ebay for 10 bucks incl shipping

Everything I've read about it says it safe for all humans and animals. The only active ingredient is the bacteria which is incapable of being infectious to humans but its probably a good idea to follow the label.

:rofl:

I was just thinking the same thing! The soap trick certainly sounds easy, but I have to say that I find the idea of creating a small ecosystem very appealing. I looked at some butterworts on line and they look very interesting (and indeed, beautiful). One question, can butterworts survive after they have eaten all the bugs? Thanks everyone for this interesting discussion!

John

i dont think Butterworts can get rid of all the bugs. They can control them - catch quite a few. also Butterworts multiply easily. I would advise also a Drosera or 2. seems to catch more but no flowers. and the drosera can't dry out between waterings and needs distilled water [also better choice for Butterworts]

I bought a Drosera locally at the recomendation of the dealer. He said it was the most effective carnivorous plant at dealing with black gnats in houseplants of all sorts, including orchids. I watered it with distilled water and kept it in the required container of water halfway up the pot. It was very effective at catching the black gnats but decided it was unhappy with my growing conditons and croaked on me. I am going back to soap. I bet it would have liked a greenhouse better than my living room. Too dry an atmosphere I believe. It was an interesting plant. Carol

Dose the color of the Drosera has something to do with it? I seen different color of it and I try to get the right kind.

You have to be able to keep the Drosera's "leaves" moist or it will be unhappy. My home was too dry for it. I may try another when we get a greenhouse. Carol

My D. Adelae is creating many plantlets...
It just got sunburned on my window ledge more than a week ago but it seems to be recuperating. I think a saucer with distilled water should be enough. How long have you had it for? There are many different species so maybe some are easier to grow.
I think when leaves are happy and there is high light they get more reddish coloration.

gnats seems to be attracted by it and many get trapped and get digested pretty fast.

My Pinguicula Moctezumae gets gnats as welll. not as many but propagates easily.
You could try that. I think it requires less humidity and to slightly dry between watering. and it is less finnicky about distilled water. I read you can propagate it by leaf cuttings [you need to use a healthy / new leaf and get the whole leaf just right off the stem]