Pheromonal dominance/recognition signals in primitively eusocial bees

One of the characteristics of social insect colonies is the division of reproductive efforts. Mostly, oviposition is limited to the queen while workers are engaged in brood care and other non-reproductive activities. Behavioural or pheromonal mechanisms, or both, maintain the reproductive dominance of the queen. So far, no information exists on the chemical structures of pheromonal dominance/recognition signals in primitively eusocial bees. Therefore, in a comparative approach, we are studying the evolution and phenotypical plasticity of pheromonal recognition and dominance signals in primitively eusocial bees. Our aim is to identify semiochemicals with a function in the regulation of worker reproduction and compare the odour bouquets of queens and different functional worker groups in primitively eusocial sweat bees and in bumblebees. Furthermore, we are studying the mechanisms of regulation of worker reproduction and the question why the queen looses her reproductive dominance at a certain phase of colony development.

Communication within a social insect colony is thought to rely primarily upon odours (pheromones). Yet how individual workers recognise and discriminate amongst relatives within a colony (e.g. full sisters versus half sisters) is currently not known. In a further collaborative project we want to identify the components of a social bee’s odour that are used in kinship discrimination.