(Thaumatomyia notata)
Biology:
Stalk flies are small, about 2 mm long, mostly yellow-black colored flies with 3 shiny black longitudinal stripes on the back. The larvae develop throughout the summer in meadows, fields and pastures and feed predatorily on root aphids and gall-inhabiting aphids.
The adult flies then often seek out buildings in the fall and enter houses to overwinter.
Damage:
In this context, only the mass occurrence of adult flies, which can become an unpleasant nuisance as house pests in the fall, is of interest. Suitable, tall, light-colored buildings (high-rise buildings, church steeples, etc.), which are often used as winter quarters for several generations, are often black with flies. The animals do not feed or reproduce in the wintering hideout.
Tip:
During the fly season in the fall, windows should remain closed or fly screens should be installed to prevent increased intrusion.
