Bees – Apis mellifera – play a critically important role in human society. They sustain food production – the Food and Agriculture Organization of the United Nations (FAO) estimates that of the 100 crop species providing 90% of food worldwide, 71 are pollinated by bees – and biodiversity by providing essential pollination for a wide range of crops and wild plants.
As well as their crucial enabling role as pollinators, bees – particularly honeybees – contribute to human wealth and wellbeing directly through the production of honey and other food and feed supplies such as pollen, wax for food processing, propolis in food technology, and royal jelly as a dietary supplement and ingredient in food.
But honey bees are in trouble. In recent years, beekeepers have reported unusual weakening of numbers and colony losses, particularly in North America and western Europe.
No single cause of declining bee numbers has been identified. However, several contributing factors have been put forward. These fall broadly into three groups: