I have little tiny flies and larvae in my soil - Ask Extension
We just planted a bunch of seeds inside my house and they've all come up! First time we've done this in years. We noticed a lot of little flies and no...
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I have little tiny flies and larvae in my soil #866366
Asked April 29, 2024, 5:19 PM EDT
We just planted a bunch of seeds inside my house and they've all come up! First time we've done this in years. We noticed a lot of little flies and now the soil is full of those tiny little white specks, larvae I think. The soil we used must've been infected. Do you have any quick and successful ways to get rid of those? Or can you point me to info about this?
Thank you!
Northwest Arctic County Alaska
Expert Response
Hi Stacey, can you send me some photos of the flies/larvae? You can email them to me at <personal data hidden>
Thanks!
Thanks!
I attached a couple of pictures of the flies. Couldn't get the tiny little larvae. I don't see them anymore. Any help you can provide would be very appreciated.
Thank you!
Stacey
I got a video of the larvae moving!
Hi Stacey, unfortunately this system doesn't support video files so I can't see the larvae. The photos of the flies are too far away for me to ID as well. Typically the most common insect people have issues with in potting soil are fungus gnats. These insects typically can be managed by allowing the soil to dry out between waterings, but with new seedlings that can be difficult to do. They typically are not damaging, more of a nuisance.
One thing that may help is getting some yellow sticky cards -- the adult flies are attracted to the yellow but get stuck when they contact the card. This won't eliminate an infestation but it will reduce the number of adults breeding and flying around in the home until the seedlings are transplanted outdoors.
You can find some more information about fungus gnats indoors in this article from Iowa State Extension: https://www.extension.iastate.edu/news/watch-fungus-gnats-house-and-take-action-if-found
One thing that may help is getting some yellow sticky cards -- the adult flies are attracted to the yellow but get stuck when they contact the card. This won't eliminate an infestation but it will reduce the number of adults breeding and flying around in the home until the seedlings are transplanted outdoors.
You can find some more information about fungus gnats indoors in this article from Iowa State Extension: https://www.extension.iastate.edu/news/watch-fungus-gnats-house-and-take-action-if-found
Thank you! I'll look at that site and also order some of those sticky cards you mentioned. It's good to hear that they won't kill my seedlings.
Stacey
Hi Stacey, for the most part fungus gnat larvae are feeding on fungi and decaying organic matter in the soil. Occasionally if populations get really high the larval activity can disrupt root growth of small seedlings, but this is not the norm, and the sticky cards should help keep them in check.
