Caring for Pollinators - Bundesamt für Naturschutz

Ssymank & Kearns Flies – Pollinators on two wings
The life cycle of an aphidophagous flower fly like e.g. Episyrphus balteatus can be
completed within only 15 – 20 days under optimal conditions. Eggs are laid in aphid
colonies,
larvae hatch immediately, fist larvae mould after 1 day, the second larvae mould
after 2-3 days and larval stage 3 is devouring up to 300 aphids per night until it pupates. The
newly emerged adult is after a short time ready for mating and giving rise to a new
generation.
Fig. 24 a: Third stage larvae of
Syrphus eating aphids.
5. Plant-pollinator interactions
Fig. 24 b: Flower fly pupae
before hatching (Syrphus).
Pollinators
have a keystone function in ecosystems.
Without pollination many wild plants could not reproduce
and survive. Animals, too, are indirectly
dependent on
pollination services, as they feed on fruit or plants that
would not exist without pollinators. Pollination is an
ecosystem service that maintains wild plant and crop
diversity, guarantees food safety and is a cornerstone of
animal diversity. Flies and bees are the most important
pollinator groups. Over 71 families of Diptera are known
to visit and pollinate flowers, linking the fate of plants and
animals. Depending on the region, the time of the day,
the flowering phenology and weather conditions, flies
may be the main or exclusive pollinators, or share
pollination services with bees and other pollinator
groups.
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Fig. 24 c: Newly emerged
Episyrphus balteatus, male.
Fig. 25: The flower fly Chrysotoxum
bicinctum visiting the small flowers of
Polygonum aviculare on a field margin in
western Germany.