Caring for Pollinators - Bundesamt für Naturschutz

Ssymank & Kearns Flies – Pollinators on two wings
that up to 80% of the regional flora may be visited by flower flies. Preferences for certain
colours, flower types, flight height and phenology of simultaneously flowering plants usually
ensure a high flower constancy of flower flies. With their high flight and flower-visiting activity
they can be quite effective pollinators. Even long distance pollen transport is possible by
migrating species like Eristalis tenax or Helophilus species.
Fig. 21: On forest margins Dasysyrphus tricinctus is
pollinating Euphorbia-species
Many flower fly larvae play an important
role in biocontrol. About 40% of the
species have zoophagous larvae, mainly
eating crop-damaging aphids. Some
species, such as Episyrphus balteatus in
Europe can reproduce rapidly, producing
large numbers of eggs and up to five
generations per year. Females can smell
aphid colonies and and use olfactory
cues to oviposit directly in or in the
vicinity of the colonies. Provided seminatural
structures are present in a
habitat, rapid population growth and
effective biocontrol preventing aphid
outbreaks is possible.
Fig.
23: The flower fly Rhingia campestris comfortably leans
back and probes the pollen of a Nepeta garden mint with its
long proboscis.
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Fig. 22: In continental dunes on the dry
sparse sandy grasslands the purple flowers
of Armeria elongata are visited by the flower
fly Chrysotoxum festivum.