Caring for Pollinators - Bundesamt für Naturschutz

Ssymank & Kearns Flies – Pollinators on two wings
that even crop plant - pollinator systems are incompletely studied. Many cases of “unknown”
pollinators or order-level indications of “Diptera” indicate the need for more research.
Today, ecologists are concerned that
climate change may decouple the
synchrony of inter-dependent
organisms. For the majority of flies, we
do not have baseline phenology
information. For flower flies (Syrphidae)
the data are better than for many other
small Diptera groups. Examples of
changes in range and phenology of
flower flies exist – however possible
desynchronisation of flowering plants
and their pollinators have not yet been
studied. There is evidence of parallel Fig. 29: One of the biggest European flower flies Volucella
pollinator and insect-pollinated plant zonaria, mimicing hornets, exploiting nectar from Knautia
arvensis with its long proboscis in a dry calcareous grassland in
decline for flower flies and bees in UK western Germany.
and NL (Biesmeijer et al. 2006). The
factors threatening the species are mostly
unknown. Data from other countries is largely
absent. Many pollinating Diptera groups are not even assessed in Red-data-Books as no
data or no fly specialists exist.
Fig. 30: The flower fly Ischiodon aegypticus visiting the
spurge Euphorbia millii, a wide-spread cultivated plant,
in its natural environment in Madagascar.
Fig. 31: The flower fly Parhelophilus frutetorum walking
over the umbels of Heracleum sphondylium, freely
offering nectar and pollen.
What consequences can we expect from the loss of pollinators? To what extent can any one
pollinator be replaced by another? The answers to these questions are unknown and
urgently need investigation. The
loss of honeybees to Colony Collapse Disorder has led to
severe declines of bee colonies in the U.S. Unwise application of pesticides has caused
honeybee losses again and again. The loss of honeybees has not only beekeepers and
ecologists, but the general public alarmed. And yet loss of natural pollinator communities
may cause dramatic changes in ecosystems and biodiversity. Our current knowledge is too
48