Anthropogenic land-use changes as a key challenge for honeybee foraging and health

Interest in bees has been growing in recent years, mainly because it has become clear that bees are having an increasingly hard time in the modern world and that humans are responsible for, and affected by, a decline in the number and diversity of pollinators. The honeybee (Apis mellifera) is a pollinator of particular importance for many agricultural crops and natural plants, but declining or stagnating colony numbers, in combination with an increasing reliance on bee-pollinated crops, have led to worries about their pollination services in many areas, including the UK.

Honeybees face numerous new challenges in our modern world, including pesticides, climate change and emerging diseases. A key challenge is rapid environmental change, mainly the conversion of natural and semi-natural land into urban or intensively farmed land. Honeybees might simply no longer find enough food in many modern landscapes.

This results in nutritional stress, which is linked to increased susceptibility to diseases and parasites. Since honeybee diseases can spill over to wild bees, poor honeybee health is of a wider epidemiological concern for the conservation of pollinator communities.

A potentially important, but unexplored reason for poor colony nutrition is the honeybee's unique foraging method. Honeybees use the famous waggle dance to communicate about high-quality food sources. Karl von Frisch made the Nobel Prize-winning discovery that, while dancing, bees transmit information about the direction and distance of the food source to surrounding bees.

He called this the "dance language". This communication helps colonies to exploit the best food sources in their environment, but it is also inherently time-consuming because other bees wait inside the hive for dance information. Computer simulations and empirical research have demonstrated that the "dance language" can be detrimental to colony success in some habitats, potentially resulting in a poor nutritional state.

We propose an ambitious experimental approach to test the hypothesis that the honeybee "dance language" is no longer beneficial in many modern landscapes and significantly contributes to nutritional stress and poor health. We will interrupt dance communication and measure how this affects the quantity and diversity of collected food sources and the health of colonies in different landscape types - (1) urban, (2) agricultural and (3) semi-natural - in 24 different sites across the southwest of England.

Specifically, we will explore how land-use and communication affect the prevalence of important drivers of honeybee colony loss in the UK, including Varroa mites and deformed wing virus (DWV). Next-generation-sequencing will be used to test how the different experimental conditions affect the expression of health-relevant genes and laboratory learning tests will establish whether the cognitive performance of bees is related to land-use, communication treatment and the nutritional state of colonies.

The results are expected to transform our understanding of how anthropogenic land-use affects the ability of honeybees to exploit food sources and they will allow us to predict how anthropogenic landscape changes will affect bee health.