tiny flying bugs indoors

Asked November 5, 2018, 4:06 PM EST

Hi. I have a small amount (but annoying) of tiny flying bugs - less than 1/8" long - indoors. I tried spraying all of my indoor plants, but there has been no change. I've heard from other folks in the Twin Cities that they have the same thing this Fall. What could they be? Will they ever leave??

Hennepin County Minnesota fungus gnats

1 Response

In the absence of a picture of these insects, my best guess is that they are probably fungus gnats. The larvae of the adult gnats feed on organic matter in the moist soils of potted plants. This is especially true for potted plants that had been outside for the summer and have recently been brought inside. The adults are perfectly harmless, either to you or to your plants. Spraying your plants will not be an effective control mechanism since such sprays have no effect upon the larvae in the pot.

I have included below several publications that describe this insect, how to prevent its spread, and general remedial procedures:

http://extension.colostate.edu/topic-areas/insects/fungus-gnats-as-houseplant-and-indoor-pests-5-584/

https://extension.umaine.edu/home-and-garden-ipm/common-name-listing/fungus-gnats/

https://ohioline.osu.edu/factsheet/ENT-59

http://apps.extension.umn.edu/garden/diagnose/insect/indoor/flies/small/fungus-gnats.html

https://extension.umn.edu/product-and-houseplant-pests/fungus-gnats

Good Luck!!