Recently I spotted relatively small flying insects gathering around the pots inside my flat.

There are smaller than fruit flies, probably around 1mm - 2mm long, blackish, and fly somewhat erratically. As far as I can tell the insects are active mostly during the day.

I didn't spot any obvious damage to the plants so far, but I might have miss something.

The location is relatively warm (southern window, above heating sink), and excluding the soil in the pots, rather dry.

Image of insects

  • Geographical location: Central Europe
  • Time of observation: Late summer, early autumn.

I'd be grateful if someone could help me identify this species.

  • 1
    $\begingroup$ Hello and welcome to Bio.SE! Take the tour to learn about the site and earn yourself your first badge. Your description is rather accurate, nice first question! $\endgroup$ Commented Oct 12, 2018 at 16:06

1 Answer 1


Looks like some sort of fungus gnat though I won't make any attempt to ID a particular species. Note that fungus gnat describes a very wide range of species over 6 families, though yours looks most like the flies from the family Sciaridae (Wikipedia notes there are ~600 species in Europe).

Fungus gnats feed on organisms decomposing soil, which are most present when the soil is moist, especially if overwatered. The damage you will experience, if any, would be to the roots, rather than visible on the leaves, though you will see wilting if the damage becomes significant.

You say things are dry, however, the important place is the soil. You will deter, though probably not completely eliminate, the fungus gnats if you let the soil dry between waterings (in my personal experience with fungus gnats this approach was sufficient). Some specific parasitic nematodes are also used for pest control of fungus gnats, if they are available in your area.

  • $\begingroup$ Agreeing with @Bryan Krause even as far as family; if we're both right in that respect, species-level identification requires a compound microscope and at least some dissection (look for "Sciaridae 'sp. nov.'" in your favorite search engine; the open access results will give you some idea what specialists seek in preparing their descriptions). $\endgroup$
    – user32396
    Commented Oct 14, 2018 at 21:25

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