kenisaac said:
If you grow fungus in your houseplant soils or your drains, the fungus gnat will come find you! As fungus / decaying matter is a food source for the larvae of the fungus gnat, and moisture helps this fugus grow, we have inadvertently provided the right conditions for the fungus gnat to complete its life cycle of egg, soil-dwelling larvae, and adult. And as they exist outdoors, indoors in your household drains, and prevalent in greenhouses, they probably will find you.
This article link below is about as good as any, and while I always suggest you get your information from an educational source (such as a university extension service or a university study,) this article in the NGA files is consistent with my experience with the fungus gnat and monitoring and control methods. I wish they had listed footnotes, so we all can check the actual sources like any university article or study would do. Most of the biological controls can be pricey if you have just a few plants, other than mosquito dunks or bits as your source of the BTi.
https://garden.org/learn/artic...
NOTE: get a positive ID on what your "persistent black fly" is, because what attracts & controls "fruit flies" (Drosophila melanogaster or similar) won't similarly work with "fungus gnats" (often Bradysia species.) If you have one on your 'yellow stickie,' look at it closely and match it to photos-sometimes the wing patterns viewed with a hand lens gives the positive ID. Put your yellow traps touching your soil, as these guys are bad flyers, and often appear to be skipping across the soil- I'm not sure if the yellow color is attracting them as much as their bad eyesight is allowing them to bash headlong into the trap.
Also NOTE that yellow traps and potato wedges (look that one up) are often referred to as "monitoring," and not control, as they won't be your total solution. Water less AND\OR change out your soil to quicker draining and non-larvae infested, if needed. It's a long fight, and be consistent.
Additional NOTE: I found the fun route-it's now a game! I use carnivorous plants (see below) now as my fungus gnat monitor (no more yellow traps,) and they are FAR MORE ENJOYABLE to me, and less disgusting to my family! While it certainly means learning to grow new plants, I have to admit I'm disappointed I don't see any gnats around my plants right now. If I swat a fly or squish a spider, it's gonna end up on the carnivore leaf! And yes, there are NO bugs on those leaves, so I'll probably need to feed them something else until the fungus gnats return again. And, yes, they will return, because apparently I grow fungus WITH my houseplants.
Pinguicula gigantea
Drosera capensis broadleaf
« Return to the thread "Persistent Black Fly"
« Return to Ask a Question forum
« Return to the Garden.org homepage
