Dark-winged fungus gnats
Dark-winged fungus gnats are small, delicate, mostly black insects, which are approximately 1 to 6 mm long. They are very active and often bustle about on the soil in flowerpots and around the pots themselves. The females lay their eggs in the ground. The thin, elongated larvae are translucent white and have a black head. They live in potting soil and rotting substances and feed primarily on decaying organic matter and mushroom spawn.
In the event of a severe infestation, the larvae of the dark-winged fungus gnats can also attack living plant tissue at the roots and stalk and cause damage to various crops, ornamental plants and also mushroom cultures, for example. The adult gnats can sometimes be annoying and unpleasant when they fly into rooms, onto window boxes and around flower pots.
Try to avoid overwatering as this helps the dark-winged fungus gnats to develop. You can significantly reduce an infestation using sticky yellow fly traps, which are available in retail outlets.