UNEP reports on bee mortality

The report of UNEP (United Nations Environment Programme ) is explicit: the biodiversity of bees and plants is currently reducing at a rate of up to 10 % per decade. The decline of pollinators is observed with great concern. Biodiversity and the guaranteeing of production are both threatened. If plants are fertilized by animals, wild plants grow better. And on these in turn depend other functions and organisms in the ecosystem. The same goes for many crops whose yield and quality are significantly improved when pollinated by insects.

Because of the close link between the evolution of bees and flowers, the anatomy of a given plant is sometimes so adapted to a specific animal that no other animal can fertilize it. In the case of these specialised species, the loss of plant or animal pollinators results in the loss of a species partner. In Switzerland, the value of honey bee production is estimated at 70 billion Swiss francs annually.

Observable loss in the world, except Australia

The UNEP report gives an overview of the losses in different regions:
– In Europe since 1965, there has been a decline in the production of colonies. Since the late 1990s, there are reports of previously unknown disorders among bee populations.
– In North America the number of producing colonies has halved over the past 50 years. In the United States the recent appearance of excessive bee mortality is designated as Colony Collapse Disorder (CCD) or colony collapse syndrome. In 2006 and 2007, of 577 beekeepers surveyed, 29% said they had suffered damage due to CCD, with losses of up to 75% of the population.
– In China, losses have been reported in recent years but are not clearly attributable to a single cause.
– In Japan, losses of up to 25 % are reported, but the cause is not certain.
– Australia is so far untouched by Varroa. The country is trying to protect its bee population by strict quarantine regulations. Currently, there are no reports of colony losses.
– In Africa, only statistics for Egypt are available. Beekeepers whose colonies are on the banks of the Nile show signs of colony collapse. An experiment showed that the symptoms disappeared when the colonies were taken to a place where the vegetation was more diverse.

Reasons for excess bee mortality

Among the main possible reasons for the decline in bee populations, the UNEP report lists:
– Destruction and fragmentation of habitats.
– Increasing parasite infestation and expansion of imported diseases.
– Air pollution by aerosols, which blocks the symbiotic relationship between pollinators and plants. Although diurnal insects orient themselves mainly by sight, smell plays a vital role in guiding pollinators.
– Electromagnetic fields, especially mobile phone antennae.

Agrochemicals can be directly harmful to pollinators, killing or having negative influences on their reproduction. The report cites:
– Herbicides kill pollen and nectar plants, and as a result also the food sources and potential nesting sites for the larvae of wild bees, butterflies, etc.
– Repeated exposure to agricultural pesticides or those used by beekeepers to fight against parasites, can weaken the immune system of bees.
– Systemic pesticides, especially neonicotinoids, deposited not only on the plant, but carried by the sap into all parts of the plant. Treated plants become permanent sources of trouble to non-target organisms, such as pollinators.