Learning to communicate: How do pheromones work in social and solitary bees and how did they evolve?

Honeybees, bumblebees and other bee species are facing a multitude of threats from disease, pesticide exposure and loss of habitat. These threats have resulted in alarming declines in bee numbers, which is a concern for food security, biodiversity and conservation.
Probably the best known and arguably the most important bee species is the honeybee, Apis mellifera. This species and the bumblebee are the most extensively managed pollinator species globally and much of the research on bees has focussed on these two species. These bees are both ‘eusocial’ – they live in colonies with hundreds to thousands of individuals. In each colony, there is only one reproductively active female who is responsible for the majority of reproduction and workers carry out most other colony tasks.
However, the UK is also home to 250 species of solitary bees – these bees spend the majority of their lives on their own, only getting together to mate, and individual females forage, lay eggs and collect provisions for their offspring.
The transition between solitary to eusocial living has occurred multiple times in bees and is one of the major and most successful life history transitions in animal evolution. Understanding how these transitions occurred addresses a major question in evolutionary biology, but also has practical importance for the management of these important species.
This transition between solitary and social living has required the elaboration of complex methods of communication between individuals within a species, and in most eusocial insects this complex communication is carried out using pheromones.
Pheromones are crucially important in all bee species and act as a primary means of communication in social bees. The most extensively studied bee pheromone is honeybee queen mandibular pheromone (QMP) that inhibits worker reproduction, as well as inducing young workers to feed and groom the queen, and to perform colony-related tasks. Other pheromones within the hive, particularly those produced by the brood, also regulate a range of behaviours in the hive, in particular, modulation of sucrose response thresholds and inhibiting ovary development in workers. These pheromones also affect foraging behaviour and increase in the number of foraging trips and the size of pollen loads.
My research to date has been primarily focussed on understanding how worker bees respond to queen pheromone (e.g. [1]) and how the response to QMP may have evolved [2]. But the pheromones found in honeybees are markedly different to bumblebees and also to solitary bees – how did they evolve?
This project will combine behavioural ecology with molecular approaches to understand how these mechanisms of communication work and how they evolved This project will use solitary bees (e.g. the red mason bee Osmia bicornis) and social bees like honeybees and bumblebees to address this question.
Communication is not only central to the function of social bee colonies but also for mating and other intra-species communication in solitary bees. Using a combination of laboratory and field studies this project will also address whether these fundamental communications are disrupted by environmental influences, like climate change and pesticide exposures in solitary and social bees.
This project directly addresses a key question in evolutionary biology but also has practical importance. The honeybee is intensively managed for pollination of crops contributing £651 million to the British economy annually and is incredibly important for the security of our food supply. Understanding how to control pest species without harming beneficial insects, like pollinator species, is of paramount importance. Understanding more about how social insects and solitary bees function will assist with these goals. Ultimately it is hoped that this knowledge about the fundamental biology of these important insects will also help inform conservation efforts aimed at maintaining bee biodiversity in the UK and globally.
For details please contact Dr Elizabeth Duncan ([Email Address Removed])