I don’t have a fly problem, I have a carnivorous plant deficiency

I’m over wintering lots of plants in my basement. I already have many houseplants. Added to that, the odd bowl of compost scraps that go out a day late, there’s the inevitable fruit fly and fungus gnat problem.

My favourite Bill Mollison quote is You don’t have a slug problem, you have a duck deficiency.

I have a carnivorous plant deficiency. Has anyone else come to this conclusion solving their own fly problem? What would work well indoors around 14’C to 18’C?

Awesome twist on that classic quote!  I don't know their growing specifics, but pitcher plant has been found useful against smallpox and a lot of other illnesses.  COuld be a good option.

This may just be me, but when I tried keeping a pitcher plant to address my gnat problem, I was finding that the plant didn't attract or eat any bugs. The same thing happened when I was a kid and had a venus fly trap. I would try to feed it, and the traps would never respond to the presence of bugs. From my understanding, the plants evolved to eat insects because the soils they normally grow in are very nutrient poor. So they had to get their nutrients from insects, which are abundant in those contexts. I wonder if when planted in potting mix and/or given fertilizer (as I would expect people wanting to grow out plants to sell would do), the plants don't need to expend energy on attracting and consuming bugs anymore, because their need for nutrients is met? I guess this is a long way of saying, maybe for them to help with bugs, they need to be in a low nutrient growing medium?

I have a pitcher plant in a cool, north facing window that does well. It doesn't seem to attract fruit flies or gnats so much. They might just not be the right kind of bugs cause the plant catches wasps and houseflies all the time, and the occasional stinkbug, too.

We used to have an ant nest that we tolerated in a pot of impatiens right below the pitcher plant. At some point we noticed there didn't seem to be any ants around anymore.  I started investigating and saw that the pitcher plant was dangling into the impatiens on one side. Started checking pitchers and they were full of ants. So they're definitely good for some bugs.

I haven't had venus fly traps since I was a kid, but I remember killing them pretty fast by feeding too much. Like Heather said, they don't like too many nutrients and closing the trap all the time ages them more quickly or something like that.  You might need an impractical number of them to keep up, depending on how gnatty your problem is.

Maybe there's a kind of pitcher plant that likes wee flying things more that the common houseplant type.

Oh, and my pitcher plant came in a pot of maybe pure peat moss or something similar. I transplanted it last year and don't remember what it was anymore. Not a nutrient dense growing material, anyway. The instructions on the tag specifically said not to fertilize, so at least some of the growers have that part figured out.

Pitcher plants are about the only option that will kill enough flies to make a difference. You'll also need quite a lot or at least I would. Remember they need watering with rainwater if you have hard water.

My friend has a pot with at least 3 types of carnivorous plants in it and she told me it doesn't like to live indoors - only if the temps are below freezing does she bring hers in.
She does have them in almost pure sphagnum moss -  so yes, very nitrogen poor soil.
I'll try to remember to ask her which bugs they catch.

You could try researching non-toxic sticky traps to see if fungus gnats are attracted. Vinegar traps with a drop of detergent to break the surface tension works for some people with fruit-fly problems. Fruit-flies are particularly attracted to rotten stuff, so make sure you didn't bring in anything with poorly decomposed leaves in the base for example.

Traps you have to set won't be as nice as plant traps, but you might need them to get the problem under control, and then the natural systems will help from there. Do any spiders like gnats?

I was going to say maybe you have a frog deficiency, but then I remembered I've seen hummingbirds eating gnats. So maybe you have a hummingbird deficiency. (just one specific kind I've seen so far that does it, not all of them. They do poop a lot, not sure what kind of creature you can rope into cleaning that up.)

I never had good luck with Venus Fly Trap inside. They are happy in the little stream section of my garden pond and since they always suffered by bringing them inside, I decided not to mess with it and just left them outside one fall to die. But they didn't and have been growing there ever since. Temps below 0 F have not killed them, they even bloom. There is a little area maybe 3 sq feet where the water is two or three inches deep. I put a piece of partly rotted driftwood in it and filled it with leaves and stuff.  I had read that these plants grow in bogs, so I tried to simulate one and seems to have worked. The hollow, rotting wood planter keeps them above the water, but it and the rotting leaves stay wet.

They apparently like it there; biggest problem is the big assed frogs are always stomping on them, I don't like that, stupid frogs! And they, the fly traps, eat dragon flies, I don't like that either, stupid Venus Fly Traps!   Ain't much that can catch a dragon fly, but they can.

I reckon that don't help much with your indoor problem. I've never had too much of a problem with that but some kind of little spiders do live in my Christmas cactuses.

Well reading all the replies has brought a big smile to my face!

I was initially thinking about sundews - Drosera family.

The European and North American verities hibernate, so not much good this time of year. There are ornamental sub-tropical species that I thought might be the answer if they can deal with the relatively cool but not cold temperatures.

I’ll continue to investigate and look into pitcher plants. I’ll probably avoid venus fly traps.

Cheers

Teresa said, "I was going to say maybe you have a frog deficiency, but then I remembered I've seen hummingbirds eating gnats. So maybe you have a hummingbird deficiency.

I was going to say Edward has a chicken deficiency then I remembered these plants are in his basement.

Maybe a few bats might work and provide guano.

Hopefully some of the methods suggested will solve the problem.

Edward Norton wrote:I was initially thinking about sundews - Drosera family.

It was my friend's sundews I was thinking might be the most helpful from your description. I think she took some of those in for the winter, but I will check.

Just back from my friend: "Yes, Droceras are what he needs. They’re the ones I brought indoors.

Venus fly traps need prey big enough to trigger at least two hairs, and continue to trigger them for a time. Fungus gnats can’t do that. And I don’t think they’re attracted to pitcher plants. There are two genera of pitcher plants – one genus is temperate and the other is tropical. The tropical ones need to be indoors in the winter, but I don’t think they’ll help with fungus gnats."

Hopefully that helps.

Edward Norton wrote:Well reading all the replies has brought a big smile to my face!

I was initially thinking about sundews - Drosera family.

The European and North American verities hibernate, so not much good this time of year. There are ornamental sub-tropical species that I thought might be the answer if they can deal with the relatively cool but not cold temperatures.

I’ll continue to investigate and look into pitcher plants. I’ll probably avoid venus fly traps.

Cheers

I am so grateful for this thread!
I have also been thinking of carnivorous plants to solve my fruit fly (drosophila) problem. Thank you to the person who explained the mechanism that Venus flytraps use, as that was what I thought would work. My usual problem with house plants is that my house is generally too cold for tropicals. Although I have been getting the temps up to the high 60s and even 70 during the day, it is often in the low 60s and much colder on window sills, even with double pane windows, in Winter when the temps are down to the aughts or single digits.  Would anyone be willing to share their knowledge of the Drosera family as to temperature tolerances and whether they would catch fruit flies?
Thanks!

I allow some web-building spiders to remain in my house, and they do a pretty good job of keeping most of the flies down.  I also use the sticky traps for fruit flies as necessary -- if you can locate them right over or next to whatever is attracting the fruit flies, they do a pretty good job, too.  Outdoors, I rely mostly on chickens and natural predation.  

However, I'm a little cautious about the spiders now, after getting bitten by a brown recluse spider last summer.  I would really rather not repeat that experience!  They aren't web-builders, though, and sticky traps on the floor next to the wall in areas where you think they might be getting into the house should get rid of them.

I have noticed if you abandon a cup of coffee with cream that every fungus gnat for miles around will come drown itself in it. Plain coffee or sugared coffee doesn't have the same effect.

Long term, a little surface treatment of the pots I bring in with that larvae killing diatom sand stops the gnats.