Fruit flies hanging out in a plant. Oh bother.
August 9, 2019 9:03 AM   Subscribe

I’ve got some pothos I’m trying to propagate so I have it in water for root development. I was gone for a week, and now there are lots of fruit flies hanging out there. I know general fruit fly measures, but I don’t want to ditch these plants—the roots aren’t quite developed enough for soil yet. Will changing to fresh water diminish the flies attraction sufficiently to allow them to be more enticed by traps?
posted by ocherdraco to Home & Garden (10 answers total) 1 user marked this as a favorite
I would change to fresh water (there's no benefit to old water) and change regularly.

You probably want to put some fertilizer in the water. Lightly, don't nuke it, a drop or two of Miracle Gro. Or if you have a fish tank, plunk it in there. That's how I propagate pothos, and I have some that just stays there, my fish like the roots for hanging out.

You can put some sticky yellow traps by the plant to deal with the flies.
posted by Lyn Never at 9:20 AM on August 9 [3 favorites]

I bet they aren't fruit flies, but fungus gnats. Fruit flies have no reason to hang out on your pothos, fungus gnats look very similar to the naked eye, and have every reason to be there.

Here is an overview of control methods, including Neem oil, predatory nematodes, etc. But those are assuming potted plants.

Change the water or honestly just ignore the problem and it will likely go away. Fungus gnats don't really hurt plants, and they are just a minor nuisance in my experience.
posted by SaltySalticid at 9:27 AM on August 9 [1 favorite]

They’re definitely fruit flies (they’ve got those red eyes), not fungus gnats. I have had the pleasure of making the acquaintance of both. There’s not much in my apartment for them to live on, but apparently just enough such that I saw like one fly before I left, and came home to fiftyish. This is not the only place I’ve found them, just one where the obvious choice to take away attractants (dumping the water and not replacing it) isn’t what I wanted to do.
posted by ocherdraco at 9:48 AM on August 9

(And I’m pretty sure they don’t care about the pothos, just the funky water it was living in.)
posted by ocherdraco at 9:49 AM on August 9

I would take out the plants, change the water, cover the top of the vase with well-secured plastic wrap, poke small holes in it, and then thread the plants through the holes.

Another option is to just take the vase and put it outside until the roots are developed.
posted by showbiz_liz at 9:53 AM on August 9

I'm honestly not sure what kind of little flies they were, but I had luck getting tiny fruitfly-like critters out of my avocado plants by topping the soil with a layer of sand.
posted by DingoMutt at 10:18 AM on August 9

Fortunately, you needn't put the pothos in water to root them, as I've always had them root just fine in dirt. Stick a pencil in the dirt to make a hole, then insert the pothos stem. Done.

And if you determine that those are really fruit flies, this is the best method I've found to get rid of them. Any rotten fruit works great.
posted by DrGail at 11:11 AM on August 9

This is the fruit fly trap that I use and highly recommend: Apple Cider Fruit Fly Trap

However, my modifications are that I use a small, low bowl, to which I add a layer of plastic wrap snugly over the top. I puncture about 10-12 small holes in the plastic; which act similar to the funnel in the other trap posted in DrGrail's post, but is a lot less finicky to set up, and has less chance of the fruit flies sneaking back out.

And yeah, definitely change your plant's water more often -- that combined with a nearby fruit fly trap and you should be good!
posted by Jade Dragon at 1:20 PM on August 9

I also found the culprit for feeding them while I was gone! I thought I had emptied all the wastebaskets before I left, but had overlooked the one by my table/desk... and the banana peel therein. Sigh.
posted by ocherdraco at 2:17 PM on August 9

You could also try a mosquito dunk, or part of one, in the water. I just found out that it works for fungus gnats -- maybe it will work for other larvae? But maybe not -- I can believe that fungus gnats are more closely related to mosquitoes than fruit flies.

Seconding that you can propagate pothos in soil really easily. It's called "devil's ivy" in some places because it's so so invasive and hard to kill. If you want, you could always treat cuttings with rooting hormone.
posted by amtho at 6:16 PM on August 9

« Older Massively multiplayer music   |   Trouble with my therapist Newer »

You are not logged in, either login or create an account to post comments