The number of managed honeybee colonies in the US fell by 33.8% last winter, according to the annual survey by the Apiary Inspectors of America and the US government’s Agricultural Research Service (ARS).
The collapse in the global honeybee population is a major threat to crops. It is estimated that a third of everything we eat depends upon honeybee pollination, which means that bees contribute some £26bn to the global economy.
Potential causes range from parasites, such as the bloodsucking varroa mite, to viral and bacterial infections, pesticides and poor nutrition stemming from intensive farming methods. The disappearance of so many colonies has also been dubbed “Mary Celeste syndrome” due to the absence of dead bees in many of the empty hives.
US scientists have found 121 different pesticides in samples of bees, wax and pollen, lending credence to the notion that pesticides are a key problem. “We believe that some subtle interactions between nutrition, pesticide exposure and other stressors are converging to kill colonies,” said Jeffery Pettis, of the ARS’s bee research laboratory.
A global review of honeybee deaths by the World Organisation for Animal Health (OIE) reported last week that there was no one single cause, but pointed the finger at the “irresponsible use” of pesticides that may damage bee health and make them more susceptible to diseases. Bernard Vallat, the OIE’s director-general, warned: “Bees contribute to global food security, and their extinction would represent a terrible biological disaster.”